MX2008005840A - Plants having improved growth characteristics and a method for making the same - Google Patents

Abstract

The present invention relates generally to the field of molecular biology and concerns a method for improving plant growth characteristics relative to corresponding wild type plants. More specifically, the present invention concerns a method for improving plant growth characteristics comprising modulating expression in a plant of a nucleic acid encoding a class I homeodomain leucine zipper (HDZip) hox5 polypeptide or a homologue thereof;or comprising modulating expression in a plant of a nucleic acid encoding a nitrate transporter protein (NRT) or a homologue thereof;or comprising modulating expression in a plant of a nucleic acid encoding a polypeptide denoted Yield Enhancing Protein 16 (referred to as YEP16);or comprising modulating expression in a plant of a Group I glycogen synthase kinase (Group I shaggy-like kinase) or a homologue thereof. The present invention also concerns plants having modulated expression of a nucleic acid encoding a class I homeodomain leucine zipper (HDZip) hox5 polypeptide or a homologue thereof;or having modulated expression of a nucleic acid encoding a nitrate transporter protein (NRT) or a homologue thereof;or having modulated expression of a nucleic acid encoding a polypeptide denoted Yield Enhancing Protein 16 (hereinafter referred to as YEP16);or having modulated expression of a Group I glycogen synthase kinase (Group I shaggy-like kinase) or a homologue thereof, which plants have improved growth characteristics relative to corresponding wild type plants. The invention also provides constructs useful in the methods of the invention.

Description

PLANTS WHICH HAVE IMPROVED GROWTH CHARACTERISTICS AND METHOD FOR OBTAINING THEM The present invention relates, in general terms, to the field of molecular biology and relates to a method for improving the growth characteristics of plants compared to corresponding wild-type plants. or other control plants. More specifically, the present invention relates to a method for improving the growth characteristics of plants, which comprises modulating the expression in a plant of a nucleic acid encoding a hox5 polypeptide of homeodomain leucine closure [homeodomain leucine zipper ] (HDZip) class I or a homolog thereof; or comprising the modulation of the expression of a plant of a nucleic acid encoding a nitrate carrier protein (NRT) or a homologue thereof; or comprising the modulation of the expression of a plant of a nucleic acid encoding a polypeptide known as Yield Enhancing Protein 16 (hereinafter referred to as YEP16) or a homologue thereof; or comprising modulating the expression in a plant of a nucleic acid encoding a Group I glycogen synthase kinase (Group I hairy kinase) or a homologue thereof. The present invention also relates to plants that have a modulated expression of a nucleic acid encoding a HOZ5 polypeptide of HDZip class I or a homologue thereof; or having a modulated expression of a nucleic acid encoding a NRT polypeptide or a homologue thereof; or having a modulated expression of a nucleic acid encoding a YEP16; or having a modulated expression of a nucleic acid encoding a Group I hairy kinase or a homologue thereof, said plants have improved growth characteristics compared to corresponding wild type plants or other control plants. The invention also offers constructs useful in the methods of the invention. The growing world population and the dwindling supply of arable land available for agriculture drives research towards increasing the efficiency of agriculture. Conventional means to improve crops and improve horticulture use selective breeding techniques to identify plants that have desirable characteristics. However, such selective breeding techniques have several drawbacks, namely that these techniques require a lot of labor in general and result in plants that frequently contain heterogeneous genetic components that do not always result in the transfer of the desirable trait from the plants progenitors. Advances in molecular biology have allowed humanity to modify the plasma Germinal of animals and plants. Genetic manipulation of plants includes the isolation and manipulation of genetic material (typically in the form of DNA or RNA) and the subsequent introduction of this genetic material into a plant. This technology has the capacity to provide crops or plants that have several economic, agronomic or horticultural features improved. A particular economic interest trait is performance. Yield is usually defined as measurable products of economic value from a crop. This can be defined in terms of quantity and / or quality. The yield depends directly on several factors, for example, the number and size of the organs, the architecture of the plant (for example, the number of branches), seed production, leaf senescence, and more. Root development, nutrient absorption and stress tolerance as well as initial vigor can also be important factors in determining yield. The optimization of one of the factors mentioned above can therefore contribute to an increased yield of the crop. Seed yield is a particularly important trait since the seeds of many plants are important for human and animal feeding. Crops such as rice, corn, wheat, canola and soybeansthey represent more than half of the total human intake of calories, either through direct consumption of the seeds themselves or through the consumption of meat products from animals raised with processed seeds. They are also a source of sugars, oils and many types of metabolites used in industrial processes. The seeds contain an embryo (the source of new shoots and roots) and an endosperm (the source of nutrients for the growth of the embryo during germination and during the initial growth of small plants). The development of a seed includes many genes and requires the transfer of metabolites from the roots, leaves and stems to the growing seed. The endosperm in particular assimilates the metabolic precursors of carbohydrates, oils and proteins and synthesizes them into storage macromolecules to fill the grain. Another feature of particular economic interest is the feature of improved tolerance to abiotic stress. Abiotic stress is a primary cause of crop loss on a global scale, reducing average yields for most main crop plants by more than 50% (Wang et al., Planta (2003) 218: 1-14). Abiotic stresses can be caused by drought, salinity, extremes of temperature, chemical toxicity and oxidative stress. The ability to improve the tolerance of plants to abiotic stress would be great economic advantage for farmers around the world and would allow the cultivation of crops during adverse conditions and in territories where the cultivation of crops may not otherwise be possible. The ability to increase the yield of plants would have many applications in areas such as agriculture, including in the production of ornamental plants, arboriculture, horticulture and forestry developments. The increase in yields can also be useful in the production of algae for use in bio-reactors (for the biotechnological production of substances such as pharmaceuticals, antibodies or vaccines, or for the bio-conversion of organic waste) and other areas of this type. BACKGROUND OF THE INVENTION Homeodomain Leucine Closing Proteins [Homeodomain leucine zipper] (HDZip) is a family of transcription factors characterized by the presence of a DNA (HD) binding domain and a motif. of adjacent leucine (Zip) closure. The homeodomain usually consists of 60 conserved amino acid residues that form a helicel-loop-helix2-turn-helix3 that binds the DNA. This DNA binding site is usually pseudopalindromic. The leucine closure, adjacent to the C terminal end of the homeodomain consists of several repeats of heptad (at least four) where usually a leucine (occasionally a valine or an isoleucine) appears every seven amino acids. Closing leucine is important for protein dimerization. This dimerization is a prerequisite for DNA binding (Sessa et al. (1993) EMBO J 12 (9): 3507-3517), and can proceed between two identical HDZip proteins (homodimer) or between two different HDZip proteins ( heterodimers). Homeodomain genes are present in all eukaryotes, and constitute a gene family of at least 89 members in Arabidopsis thaliana. Closing leucine is also found per se in eukaryotes other than plants. However, the presence of both a homeodomain and a leucine closure is specific to plants (found in at least 47 of the 89 Arabidopsis proteins), and has been found in moss as well as vascular plants (Sakakibara et al. (2001) Mol Biol Evol 18 (4): 491-502). The closing of leucine is then located at the C-terminal end of the homeodomain, these two characteristics are joined by three amino acids. The HDZip genes of Arabidopsis have been classified into four different classes, HDZip I to IV, based on criteria of sequence similarity (Sessa et al. (1994) in Plant Molec Biol, pp412-426). Like the HD-Zip proteins from the three other classes, the HDZip proteins of class I are quite divergent in their primary amino structure outside the homeodomain and the leucine closure. Within both homeodomain and leucine closure, HDZip class I proteins are also characterized by two specific characteristics: 1) in the homeodomain, in addition to the invariant amino acids Leui6Trp48P e49 sn5? rg53, position 46 is occupied by a wing (A) and position 56 by a Try (W) (or occasionally by a Phe (F)) (Sessa et al. (1997) J Mol Biol 274 (3): 303-309, see Figure 1), which is known as class I homeodomain, and 2) leucine closure comprises six heptad, except in the case of Cera topteris richardii fern, which has seven heptad (within each heptad, the positions are named a, b, c, d, e, f and g, leucine conserved being in position d, Sakakibara et al (2001) Mol Biol Evol 18 (4): 491-502, see Figure 2). HDZip II, III and IV present a leucine closure with five heptates only. In relation to their DNA binding properties, HDZip class I proteins bind preferentially to 5-base pair sites that are spliced in a central position, CAA (A / T) ATTG (Sessa et al. (1993) EMBO J 12 (9): 3507-3517). It has been shown that different HDZip proteins either activate or repress transcription. In Arabidopsis, it was shown that ATHBl, -5, -6, and -16 act as activators transcriptional assays in transient expression assays in Arabidopsis leaves using a reporter gene (luciferase; Henriksson et al. (2005) Plant Phys 139: 509-518). Two rice HDZip class I proteins, Oshox4 and 0shox5, acted as activators in transient expression assays in rice cell suspension cultures using another reporter gene (glucuronidase; Meijer et al. (2000) Mol Gen Genet 263: 12 -twenty-one). In contrast, two HDZip proteins of Class II rice, Oshoxl and Oshox3, acted as transcriptional repressors in the same experiments (Meijer et al. (1997) Plant J 11: 263-276; Meijer et al. (2000) supra). Several HDZip class I proteins participate in the response in light in a response related to abscisic acid deficit (ABA) / water (Hjellstrom et al. (2003) Plant Cell Environ 26: 11-27-1136). Transgenic Arabidopsis that over expresses ATHBl, -3, -13, -20, and -23 HDZip class I suggest that these genes are involved in the regulation of the development of cotyledons and leaves (Aoyama et al. (1995) Plant Cell 7 : 1773-1785; Hanson (2000) in Comprehensive summaries of Uppsala Dissertations from the Faculty of Science and Technology, Uppsala). The ATHB3, -13, -20, and -23 genes are similar and form a distinct class within HDZip class I. Since these genes cause similar alterations in the form of cotyledons when they are expressed constitutively, they are known as HDZip genes. of Pointed Cotyledon (POC) [joointed cotyledon]. Hanson concludes that HDZip class I proteins that are closely related phylogenetically are also functionally related, in most cases. Ni treatment proteins (NRT) Plants lead a sedentary life and have to depend on the resources in the soil for their nutrition. Nitrogen in the soil is present mainly in the form of ammonium or nitrate. Absorption of nitrate by plants can occur through three N? 3 ~ absorption systems: a low affinity transport system that is active when the concentration of? 3 ~ is greater than 1 mM, a transport system of high constitutive affinity and an inducible high affinity transport system, both for concentrations of NO3"between 1 μM and 1 mM.The three absorption systems are regulated in a complex manner: once absorbed, the nitrate is transported in the vacuole or reduced nitrite, which in turn is further metabolized in the chloroplast Nitrate can also be secreted again into the apoplasm or into the xylem for transport to the outbreak Proteins for nitrate absorption in root cells (NRT, nitrate transporter protein) ) belong to what is known as the Superfamily of Senior Facilitators, which encompasses proteins involved in the transport of small products and that have a length of 450 to 600 amino acids with 12 transmembrane domains. The NRT proteins fall within two families, NRT1 and NTR2 (Crawford &Glass, Trenes Plant Sci. 3, 389-395, 1998) and are encoded by a family of multigenes. NRT proteins are highly conserved in their sequence, for example, NRT2 proteins from mosses share a sequence identity of 60% with protein NRT2 from dicotyledonous plants, within the group of plants the identity of sequences between NRT2 proteins is approximately 81% , which can reach up to 89% in the case of monocotyledonous NRT2 proteins. The NRT2 family of proteins in Arabidopsis was extensively studied by Orsel et al. (Plant Physiol. 129, 886-896, 2002). The family comprises 7 members, distributed in three chromosomes. The protein structure is conserved and five of the 7 NRT2 proteins are preferentially expressed in the roots of young plants. Structurally, NRT2 proteins comprise an MFS_1 domain encompassing approximately 90% of the protein and a C-terminal transmembrane domain. It is predicted that the MFS_1 domain itself comprises 10 or 11 transmembrane domains. It is considered that NRT2 proteins are mainly involved in the high affinity transport system. On higher floors, this high absorption system affinity is postulated to be controlled by a complex of two proteins, consisting of NRT2 and NAR, a protein with an uncleared function (Zhou et al., FEBS Letters 466, 225-227; Tong et al., Plant J. 41, 442 -450, 2005). Overexpression of NRT2 increased the capacity of the high affinity absorption system (Fraisier et al., Plant J.23, 489-496). NRT2 also possibly functions as a nitrate sensor (Little et al Nati, Acad. Sci. USA 102, 13693-13698, 2005). Mori et al. studied transgenic rice plants that overexpressed the NRT2 rice gene and showed that small plants with a nitrate shortage had a better uptake of N? 3 ~ compared to wild type plants. Good et al. (US 20050044585) disclose transgenic plants with high levels of nitrogen utilization proteins, and in particular aminotransferases, under the control of a root-specific promoter that may or may not be stress inducible. These plants showed an improved nitrogen absorption efficiency, but no effects on seed yield were reported. In addition, this document also discloses that over-expression of nitrate transporter proteins did not result in beneficial growth properties for these plants. In addition, NRT proteins have not yet been studied under normal growth conditions or for a cycle of full life of the plant. Performance Improvement Protein 16 (YEP16) A YEP16 polypeptide shares certain similarity with the N-terminal domain of the delta subunit, delta domain of F1F0-ATP synthase ATPase (see InterPro IPR000711 for details of the delta subunit). Hairy-type plant kinases are encoded by a family of multigenes. The Arabidopsis genome has ten hairy-like kinase-encoding genes that fall into four distinct subfamilies. The protein sequences of non-family members are highly conserved throughout the kinase domain, however, the N- and C-terminal regions differ considerably which indicates that several plant-hairy type kinases are involved in various biological processes such as, example, hormonal signaling, development and stress responses. Based on the protein sequence homology, the plant hairy type kinases can be classified into four groups (I-IV), with each of the four groups being involved in different processes (see Figure 13). In addition to the full-length cDNA sequences available for hairy-type kinases of Arabidopsis thaliana, full-length cDNA sequences are also available in public databases for hairy-type kinases from Brassica napus, Medicago sa tiva, Nicotiana tabacum, oryza sa tiva and Petunia hybrida and Zea mays, among others. AtGSKl, a gene encoding a group II Arabidopsis hairy kinase complements the salt-sensitive genotype of the mutant yeast calcineurin. In small plants, the production of the same hairy type kinase is induced by NaCl and abscisic acid. Overproduction of the AtGSKl gene has been reported as inducing salt stress and anthocyanin accumulation genes and altering intracellular cation levels, resulting in improved salt tolerance and drought. Since hairy-type kinases from different groups are known to be involved in various biological processes, it was surprising to find hairy-type kinases from two different groups involved in the same biological process, ie, responses to stress. It was unexpected to find that a hairy type kinase from a different Group II group could provide an increased tolerance in plants to abiotic stress. We have now found that modulating the expression in a plant of a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof; or modulating expression in a plant a nucleic acid encoding a nitrate transporter protein (NRT) or a homologue thereof; or modulation of the expression in a plant of a nucleic acid encoding a YEP16 polypeptide; or modulation of the expression of a plant of a group I hairy kinase or a homologue thereof provides plants having improved growth characteristics compared to corresponding wild type plants or other control plants. The present invention therefore offers a method for improving the growth characteristics of plants comprising the modulation of the expression in a plant of a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof; or comprising the modulation of the expression in a plant of a nucleic acid encoding an NRT or a homologue thereof; or comprising modulating the expression in a plant of a nucleic acid encoding a YEP16 polypeptide; or comprising the modulation of the expression in a plant of a hairy type kinase of group I or a homologue thereof. The choice of suitable control plants is a routine part of an experimental environment and can include corresponding wild-type plants or corresponding plants without the gene of interest. The control plant is typically of the same plant species or even of the same variety as the plant to be evaluated. The control plant can also be a nulligrapher of the plant to be evaluated. A "control plant" as used here refers not only to plants whole, but also parts of plants, including seeds and parts of seeds. Advantageously, the performance of the methods according to the present invention results in plants having improved growth characteristics, especially one or more of the following: improved yield, improved growth, improved biomass, improved architecture, improved cell division and tolerance improved to abiotic stress in relation to the corresponding wild type or other control plants. The term "increased yield" as defined herein means an increase of one or more of the following, each of which in comparison with the corresponding wild type or other control plants: (i) increased biomass (weight) of one or several parts of a plant, especially parts above the ground (harvestable) or increased root biomass, increased root volume, increased number of roots, increased root diameter or increased root length (of thick or thin roots) , or increased biomass of any other harvestable parts; (ii) increased total seed yield, which includes an increase in seed biomass (seed weight) and that may be an increase in the weight of seeds per plant or based on individual seeds and / or per hectare or acre; and (iii) number increased of flowers (florets) per panicle, which is expressed as the ratio between the number of filled seeds and the number of primary panicles; (iv) increased seed filling rate (expressed in terms of percentage as the ratio between the number of filled seeds and the number of florets); (v) increased number of seeds (filled); (vi) increased seed size, which may also influence seed composition; (vii) increased seed volume, which may also influence the seed composition (including the content and composition of oil, protein and total carbohydrate); (viii) increased seed area (individual or average); (ix) increased seed length (individual or average); (x) increased seed width (individual or average); (xi) increased perimeter of seeds (individual or medium); (xii) increased harvest index (Hl), which is expressed as the ratio between the yield of harvestable parts, such as seeds, and total biomass; and (xiii) one thousand grain weight (TKW) increased, which is extrapolated from the number of full seeds counted and their total weight. An increased TKW may result from an increased seed size and / or higher seed weight. An increased TKW may result from an increase in embryo size and / or endosperm size.

Taking corn as an example, an increase in yield can »manifest itself as one or more of the following: increase in the number of established plants per hectare or acre, increase in the number of ears of corn per plant, an increase in the number of rows, number of kernels per row, weight of kernels, weight per thousand kernels, length / diameter of ear, increase in seed filling rate (which is the number of filled seeds divided by the total number of seeds and multiplied by 100), other things. If we take the rice as an example, an increase in yield can be manifested as an increase of one or several of the following: number of plants per hectare or acre, number of panicles per plant, number of pimples per panicle, number of flowers (florets) per panicle (which is expressed as the ratio between the number of filled seeds and the number of primary panicles), increase in the seed filling rate (which is the number of filled seeds divided by the total number of seeds and multiplied by 100) ), increase in weight of a thousand grains, among others. Since the transgenic plants according to the present invention have an increased yield, it is probable that these plants have an increased growth rate (during at least a part of their life cycle), in comparison with the growth rate of plants of control in a corresponding stage of its life cycle. The increased growth rate can be specific to one or several parts of a plant (including seeds), or it can be substantially throughout the entire plant. Plants that have an increased growth rate can have a shorter life cycle. The life cycle of a plant can be taken as the time needed to grow from a mature, dry seed to the stage at which the plant has produced mature, dry seeds, similar to the initial material. This life cycle can be influenced by factors such as vigor, growth rate, green index, flowering time and seed ripening speed. The increase in the growth rate can be carried out in one or several stages in the life cycle of a plant or during substantially the entire life cycle of the plant. An increased growth rate during the initial stages of a plant's life cycle may reflect increased vigor. Increasing the growth rate can alter the harvest cycle of a plant allowing the plants to be sown later and / or harvested earlier than would otherwise be possible (a similar effect can be obtained with a longer flowering time). early). If the growth rate is sufficiently increased, it can allow additional seed of the same plant species (for example, planting and harvesting of rice plants followed by planting and harvesting additional rice plants all within a period of conventional growth) Similarly, if the growth rate is sufficiently increased , may allow the additional planting of seeds of different plant species (for example, planting and harvesting of rice plants followed, for example, by planting and optional harvesting of soybeans, potatoes or any other suitable plant). Additional harvesting from the same rhizome in the case of certain crop plants may also be possible.An alteration of the harvest cycle of a plant may produce an increase in annual biomass production per acre (due to an increase in the number of times (say in a year) that a particular plant can be grown and harvested.) An increase in the growth rate can also allow the cultivation of the plan transgenic crops in a wider geographic area than their wild-type counterparts, since the territorial limitations to cultivate a crop are often determined by adverse environmental conditions either at the time of planting (early season) or at the time of harvest (late season). ). Such adverse conditions can be avoided if the harvest cycle is shortened. The growth rate can be determined by deriving several parameters from growth curves, such as T-Mid points (the time required for plants to reach 50% of their maximum size) and T-90 (the time needed for plants to reach 90% of their Maximum size (among others) The use of the methods of the present invention provides plants having an increased growth rate Therefore, according to the present invention, a method for increasing the growth rate of plants is provided, said The method comprises modulating the expression in a plant of a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof, or comprising the modulation of the expression in a plant of a nucleic acid encoding an NRT or a homologue thereof, or comprising the modulation of the expression in a plant of a nucleic acid encoding a YEP16 polypeptide, or comprising the modulation of expression in a plan of a Group I hairy kinase or a homologue thereof. An increase in yield and / or growth rate occurs when the plant is in non-stress conditions or the plant is exposed to various types of stress compared to control plants. Plants typically respond to stress exposure by slower growth. In conditions of severe stress, the plant may even stop growing completely. A slight stress, on the other On the other hand, it is defined here as any stress to which a plant is exposed that does not result in the suspension of the total growth of the plant without the capacity to resume growth. A slight stress in the sense of the present invention entails a reduction of the growth of plants subjected to stress of less than 40%, 35% or 30% or preferably less than 25%, 20% or 15%, more preferably less than 14%, 13%, 12%, 11% or 10% or less compared to the control plant under non-stress conditions. Due to advances in agricultural practices (irrigation, fertilization, pesticide treatments), severe stress conditions are not often found in cultivated crop plants. As a consequence, compromised growth induced by mild stress is often an undesirable characteristic for agriculture. Mild stress conditions are biotic and / or abiotic (environmental) daily stress to which a plant is exposed. Abiotic stress conditions may be due to drought or excess water, anaerobic stress, salt stress, chemical toxicity, oxidative stress and high, low or freezing temperatures. Abiotic stress can be an osmotic stress caused by water stress (especially in case of drought), salt stress, oxidative stress or ionic stress. The biotic types of stress are typically the types of stress caused by pathogens, such as bacteria, viruses, fungi and insects. The use of the methods according to the present invention results in plants that have a higher tolerance to abiotic stress. As reported in Wang et al. (Planta (2003) 218: 1-14), abiotic stress involves a series of morphological, physiological, biochemical and molecular changes that negatively affect the growth and productivity of plants. Dryness, salinity, extreme temperatures and oxidative stress are known to be interconnected and can induce cell damage and growth through similar mechanisms. For example, drought and / or salinization primarily manifest as osmotic stress, resulting in the disturbance of homeostasis and the distribution of ions in the cell. Oxidative stress, which often accompanies an elevated temperature or a low temperature, salinity or stress due to drought, can cause denaturation of functional and structural proteins. As a consequence, these various environmental stresses frequently activate signaling pathways of similar cells and similar cellular responses, such as for example the production of stress proteins, the up-regulation of antioxidants, the accumulation of compatible solutes and the suspension of growth. Since various types of environmental stress activate similar pathways, the exemplification of the present invention with drought stress (insofar as the invention relates to the use of hox5 HDZip class I polypeptides and their encoding nucleic acids) should not be considered as a limitation to drought stress, but as a screening to indicate the participation of polypeptides hox5 of HDZip class I or a homolog thereof in the abiotic types of stress in general. In addition, the methods of the present invention can be carried out under non-stress conditions or under mild drought conditions to provide plants having improved growth characteristics (especially increased yield) compared to corresponding wild-type plants or other control plants. The term "non-stress" conditions, as used herein, refers preferably to environmental conditions that do not go significantly beyond the climatic conditions and other usual abiotic conditions that plants may encounter, more preferably conditions that allow optimum growth of the plants. Those skilled in the art are aware of normal soil conditions and normal climatic conditions for a given location. A particularly high degree of "interference" is reported between drought stress and high salinity stress (Rabbani et al. (2003) Plant Physiol 133: 1755-1767). Therefore, it would be apparent that a hox5 polypeptide of HDZip Class I or a homologue thereof would also be useful to protect the plant against several other types of abiotic stress in addition to its utility to provide plants with drought tolerance. Similarly, it would be apparent that a Group I hairy kinase (as defined herein) would also be useful for protecting plants against various types of abiotic stress in addition to their utility for providing plants with salt tolerance. In addition, Rabbani et al. (2003, Plant Physiol 133: 1755-1767) report that similar molecular mechanisms of stress tolerance and responses exist between dicotyledons and monocotyledons. The methods of the present invention can therefore be beneficially applied to any plant. The term "abiotic stress" as defined herein means any one or more of the following: water stress (due to dryness or excess water), anaerobic stress, salt stress, temperature stress (due to high, low temperatures) or freezing), chemical toxicity stress and oxidative stress. In accordance with one aspect of the present invention, abiotic stress is an osmotic stress, selected from water stress, salt stress, oxidative stress and ionic stress. Preferably, water stress is drought stress. The term salt stress is not restricted to common salt (NaCl), but may be any or several of the following: NaCl, KCl, LiCl, MgCl2, CaCl2, among others. The increased tolerance to abiotic stress is manifested by an increased plant yield under conditions of abiotic stress. Particularly insofar as the invention relates to the use of hox5 HDZip class I polypeptides and their encoding nucleic acids, said increased yield may include one or more of the following: increased number of filled seeds, total increased seed yield, increased number of flowers per panicle, increased seed filling rate, increased Hl, increased TKW, greater root length or greater root diameter, all of the above compared to corresponding wild type plants. The application of the methods of the present invention provides plants with greater tolerance to abiotic stress. The application of the methods of the present invention provides plants growing in non-stress conditions or in mild drought stress conditions improved growth characteristics (particularly improved yield) compared to corresponding wild-type plants or other plants of Control grown under comparable conditions. In accordance with the present invention, a method for increasing tolerance to abiotic stress in plants, said method comprises modulating the expression in a plant of a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof. According to one aspect of the invention, the abiotic stress is an osmotic stress, selected from one or more of the following: water stress, salt stress, oxidative stress and ionic stress. Preferably, water stress is drought stress. The present invention also provides a method for improving tolerance to abiotic stress in plants, which comprises increasing the activity in a plant of a hairy type kinase Group I or a homologue thereof, said hairy type kinase Group I has : (i) a sequence identity of at least 77% with the amino acid sequence represented by SEQ ID NO: 174; and (ii) motif I: R / H / V / N / Q E / G LK G / N and motif II: K Q / N CXXX G / A / S, where X can be any amino acid. The present invention also offers a method for improving the growth characteristics of plants (particularly increased yield) in plants grown under non-stress conditions or under mild drought conditions, said method comprises the modulation of expression (preferably the increase of expression) in a plant of a nucleic acid encoding a NRT polypeptide or a homologue thereof. In a preferred embodiment of the invention, the increase in yield and / or growth rate occurs in accordance with the methods of the present invention under non-stress conditions. Particularly insofar as the present invention relates to the use of Hox5 HDZip class I polypeptides and their encoding nucleic acids, the practice of the methods of the present invention offers an increased greenness index compared to wild type plants corresponding. The greenness index, according to what is defined in the present, is the proportion (expressed as a percentage) of yellow pixels in images of plants recorded by a digital camera. An increased greenness index may indicate a reduced or delayed senescence, which in turn allows a prolongation of the photosynthetic activity of a plant, which in turn leads to several beneficial effects well known in the art. The invention therefore offers a method for increasing the greenness index in plants, said method comprising the modulation of the expression in a plant of a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof. Preferably, the Greenness Index is increased under conditions of abiotic stress, with greater preference in water stress conditions, additionally preferable under stress conditions of drought. Preferably, when the method of the present invention comprises modulating the expression in a plant of a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof, the increased yield includes one or more of the following: increased of full seeds, increased total yield of seeds, increased number of flowers per panicle, increased seed filling rate, increased HL, increased TKW, greater root length or greater root diameter, all of the above in comparison with plants of type corresponding wild or other control plants. In accordance with a preferred feature of the present invention, there is provided a method for increasing the yield of plants compared to plants of corresponding wild type or other control plants, said method comprising modulating the expression in a plant of an acid nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof. Preferably, when the method of the present invention comprises the modulation of the expression in a plant of a nucleic acid encoding an NRT or a homologue thereof, the resulting plants have an increased yield and more particularly, an increased biomass and / or a increased yield in seeds. Preferably, the increased yield in seeds comprises an increase in one or more of the following: number of seeds (filled), total weight of seeds, size of seeds, weight per thousand grains and harvest index, all of the above compared to wild type plants corresponding or other control plants. In accordance with another preferred feature of the present invention, there is provided a method for increasing the yield of plants, said method comprising modulating the expression (preferably increasing the activity and / or expression in a plant of a nucleic acid that encodes a NRT polypeptide or a homologue thereof Preferably, when the method of the present invention comprises modulating the expression in a plant of a nucleic acid encoding a YEP16 polypeptide, increased or improved yield is an increased yield in seeds compared to the seed yield of corresponding wild-type plants.Therefore, in accordance with another preferred feature of the present invention, a method is provided for increasing the yield of seeds in a plant as compared to corresponding wild-type plants. or other control plants, which the modulation of the expression in a plant of a nucleic acid encoding a YEP16 polypeptide or a homologue thereof.

Preferably, when the method of the present invention comprises modulating the expression in a plant of a nucleic acid encoding a Group I hairy kinase or a homologue thereof, the enhanced growth characteristic is an improved tolerance to stress. abiotic. In accordance with another preferred feature of the present invention, there is provided a method for improving tolerance to abiotic stress in plants, which comprises the modulation of expression (preferably the increase of activity and / or expression) in a plant of a kinase of hairy type of Group I or a homologue thereof, said hairy type kinase of Group I has: (i) at least a sequence identity of 77% with the amino acid sequence represented by SEQ ID NO: 147; and (ii) motif I: R / H / V / N / Q E / G LK G / N and motif II: K Q / N CXXX G / A / S, where X can be any amino acid. The methods of the present invention are therefore advantageously applicable to any plant. The term "plant" as used herein encompasses whole plants, ancestors and progeny of plants and parts of plants, including seeds, shoots, stems, leaves, roots (including tubers), flowers and tissues and organs, wherein each of the above comprises the gene / nucleic acid of interest. The term "plant" also includes cells plants, suspension cultures, callus tissue, embryos, meristematic regions, gametophytes, sporophytes, pollen and microspores, again all the above comprise the gene / nucleic acid of interest. Plants particularly useful in the methods of the present invention include all plants belonging to the Viridiplantae superfamily, in particular monocotyledonous and dicotyledonous plants including pasture or forage, ornamental plants, food crops, trees or shrubs selected from the list that includes Acacia spp., Acer spp., Actinidia spp., Aesculus spp., Aga esta australis, Albizia amara, tricolor Alsophila, Andropogon spp., Arachis spp, Areca ca techu, Astelia fragrans, Astragalus cicer, Baikiaea plurij uga, Betula spp. , Brassica spp., Bruguiera gymnorrhiza, Burkea africana, leafy Butea, farinosa Cadaba, Calliandra spp, Camellia sinensis, Canna indica, Capsicum spp., Cassia spp., Centroema pubescens, Chaenomeles spp., Cinnamomum cassia, Coffea arabica, Colophospermum mopane, Coronillia varia, Cotoneaster serotype, Cra taegus spp., Cucumis spp., Cupressus spp., Cya thea dealbata, Cydonia oblonga, Cryptomeria japonica, Cy mbopogon spp., Cyn thea Dealba ta, Cydonia oblonga, Dalbergia monetary, Davallia divarica ta, Desmodi um spp., Dicksonia squarosa, diheteropogon amplectens, Dioclea spp, Dolichos spp., Dorycnium rectum, Echinochloa pyramidalis, Ehrartia spp., Eleusine coracana, Eragrestis spp., Erythrina spp., Eucalyptus spp., Euclea schimperi, Eulalia villosa, Fagopyrum spp., Feijoa sellowiana, Fragaria spp., Flemingia spp, Freycinetia banksii, Geranium thunbergii, Ginkgo biloba, Glycine javanica, Gliricidia spp, Gossypium hirsutum, Grevillea spp., Guibourtia coleosperma, Hedysarum spp., Hemarthia altissima, Heteropogon contortus, Hordeum vulgare, Hyparrhenia rufa, Hypericum erectum, Hyperthelia dissoluta, Indigo incarnata, Iris spp., Leptarrhena pyrolifolia, Lespediza spp., Lettuca spp., Leucaena leucocephala, Loudetia simplex, Lotonus bainesii, Lotus spp., Macrotyloma axillare, Malus spp., Manihot esculenta, Medicago sativa, Metasequoia glyptostroboides, Musa sapientum, Nicotianum spp., Onobrychis spp., Ornithopus spp., Oryza spp. , Peltophorum africanum, Pennisetum spp., Persea gratissima, Petunia spp., Phaseolus spp., Phoenix canariensis, Phormium cookianum, Photinia spp., Picea glauca, Pinus spp., Pisum sativum, Podocarpus t other, Pogonarthria fleckii, Pogonarthria squarrosa, Populus spp., Prosopis cineraria, Pseudotsuga menziesii, Pterolobium stellatum, Pyrus communis, Quercus spp., Rhaphiolepsis umbellata, Rhopalostylis sapida, Rhus natalensis, Ribes grossularia, Ribes spp., Robinia pseudoacacia, Rosa spp. , Rubus spp., Salix spp., Schyzachyrium sanguineum, Sciadopitys verticillata, Sequoia sempervirens, Sequoiadendron giganteum, Sorghum bicolor, Spinacia spp., Sporobolus fimbriatus, Stiburus alopecuroides, Stylosanthos humilis, Tadehagi spp, Taxodium distichum, Themeda triandra, Trifolium spp., Triticum spp., Tsuga heterophylla, Vaccinium spp., Vicia spp., Vitis vinifera, Na tsonia pyramida ta, Zantedeschia aethiopica, Zea mays, amaranth, artichokes, asparagus, broccoli, brussel sprouts, cabbages, canola, carrot, cauliflower, celery, kale, flax, cabbage, lentil, oilseed cabbage, okra, onion, potato, rice, soy, strawberry, beet, cane of sugar, sunflower, tomato, pumpkin, tea and seaweed, among others. According to a preferred embodiment of the present invention, the plant is a harvest plant, such as, for example, soybean, sunflower, canola, alfalfa, colsa, cotton, tomato, potato or tobacco. Preferably, the plant is a monocotyledonous plant, such as, for example, sugarcane. More preferably, the plant is a cereal, such as rice, corn, wheat, barley, millet, rye, sorghum or oats. Hox5 of HDZip class I and homologs thereof, and nucleic acids / hox5 genes of HDZip class I useful in the methods of the invention The term "hox5 polypeptide of HDZip class I or homologue thereof" as defined Here, it refers to a polypeptide comprising from N-terminal to C-terminal: (i) an acidic picture; and (ii) a class I homeodomain; and (iii) a leucine closure with more than 5 heptates.

In addition, the Hox5 polypeptide of HDZip class I or a homologue thereof can comprise any of the following or both: (a) a Trp tail; and (b) the amino acid motif RPFF, wherein R is Arg, P is Pro and F is Phe. Within this reason, one or more conservative changes are allowed in any position, and / or one or two non-conservative changes in any position. The reason for (b) precedes the acidic picture, when the N-terminal to C-terminal protein is examined. An example of a hox5 HDZip class I polypeptide according to that defined above comprising N-terminal to C-terminal; and (i) an acidic picture; and (ii) a class I homeodomain; and (iii) a leucine closure with more than 5 heptates; and further comprising: (a) a Trp queue; Y (b) the amino acid motif RPFF, wherein R is Arg, P is Pro, and F is Phe, is represented as in SEQ ID NO: 2. Additional examples of this type are provided in Table A of Example 1 here. A hox5 polypeptide of HDZip class I or homologue thereof is encoded by a nucleic acid / hox5 gene of HDZip class I. Accordingly, the term "nucleic acid / hox5 gene of HDZip class I" as defined herein is any nucleic acid / gene encoding a hox5 polypeptide of HDZip class I or a homologue thereof in accordance with that defined above. Hox5 polypeptides of HDZip class I or homologs thereof they can be easily identified using routine techniques well known in the art, such as by sequence alignment. Methods for sequence alignment for comparison are well known in the art, such methods include GAP, BESTFIT, BLAST, FASTA and TFASTA. GAP uses the algorithm of Needleman and Wunsch ((1970) J Mol Biol 48: 443-453) to find the alignment of two complete sequences that optimizes the number of correspondences and minimizes the number of spaces. The BLAST algorithm (Altschul et al (1990) J Mol Biol 215: 403-10) calculates the percentage of sequence identity and performs a statistical analysis of the similarity between the two sequences. The software to perform a BLAST analysis is publicly available through the National Center for Biotechnology Information. Hox5 homologs of HDZip class I comprising a class I homeodomain and a leucine closure with more than 5 heptad can be easily identified using, for example, the ClustalW multiple sequence alignment algorithm (version 1.83) available at http: // clustalw. genome jp / sit-bin / nph-ClustalW, with the parameters of alignment by default pairs, and a method of qualification in percentage. A minor manual editing can be done in order to optimize the alignment between conserved motifs, as will be apparent to a person with knowledge in the field.

The various structural domains in a hox5 HDZip class I protein, such as homeodomain and leucine closure, can be identified using specialized databases, such as SMART (Schultz et al. (1998) Proc. Nati. Acad Sci USA 95, 5857-5864; Letunic et al. (2002) Nucleic Acids Res 30, 242-244; http://smart.embl-heidelberg.de/), InterPro (Mulder et al., (2003) ) Nucí Acids, Res. 31, 315-318, http://www.ebi.ac.uk/interpro/), Prosite (Bucher and Bairoch (1994), A generalized profile syntax for motifs of biomolecular sequences and their function in automatic interpretation of sequences. (In) ISMB-94; Minutes of the 2nd International Conference on Intelligent Systems for Molecular Biology: Altman R., Brutlag D., Karp P., Lathrop R., Searls D., Eds ., pp53-61, AAAI Press, Menlo Park, Hulo et al., Nucí Acids, Res. 32: D134-D137, (2004), http://www.expasy.org/prosite/) or Pfam (Bateman et al., Nucleic Acids Research 30 (1): 276-280 (2002), http: // www. sanger.ac.uk/Software/Pfam/). The prediction of leucine closure and heptad identification can be made using specialized software, such as 2ZIP, which combines a standard superhelix prediction algorithm with an approximate search for the characteristic leucine repeat (Bornberg-Bauer et al., 1998 ) Computational Approaches to Identify Leucine Zippers, Nucleic Acids Res., 26 (11): 2740-2746, http: //2zip.molgen.mpg.de). In addition, the presence of an acidic painting can also be easily identified. A composition of primary amino acids (in percent) to determine whether a polypeptide domain is rich in specific amino acids can be calculated using ExPASy server software programs, in particular the ProtParam tool (Gasteiger E et al. (2003) ExPASy: the proteomic server for protein knowledge and analysis at depth (Nucleic acids Res 31: 3784-3788) The composition of the protein of interest can then be compared with the average composition of amino acids (in percentage) in 1 data bank Swiss-Prot Protein Sequence In this data bank, the average content of Asp (D) and Glu (E) is 5.3% and 6.6%, respectively, the combined average being 11.9% As an example, the acid table of SEQ ID NO : 2 contains 9.1% of D and 54.5% of E, the combined average being 63.6% As defined herein, an acid-rich box has a combined content of Asp (D) and Glu (E) (in terms of of percentage) above what I found It is based on the average amino acid composition (in percentage terms) of the proteins in the Swiss-Prot Protein Sequence database. An acidic picture can be part of a transcription activation domain. Transcription activation domains Eukaryotes have been classified according to their amino acid content, and major categories include acid activating domains, rich in glutamine and proline-rich (Rutherford et al. (2005) Plant J. 43 (5): 769-88, and references there) . A selected number of proteins between the HOX5 polypeptides of HDZip class I or homologs thereof further comprises the amino acid motif RPFF, wherein R is Arg, P is Pro and F is Phe. Within this reason, one or more conservative changes are allowed in any position, and / or one or two non-conservative changes in any position. This motive precedes the acidic picture, when the N-terminal to C-terminal protein is examined (see Figure 2). The presence of RPFF can be identified using methods for sequence alignment for comparison in accordance with what is described above. In some cases, the default parameters can be adjusted to modify the level of strictness of the search. For example, using BLAST, the threshold of statistical significance (known as "expected" value) for reporting correspondences against database sequences can be increased in order to show less strict correspondences. In this way you can identify almost exact short correspondences. A selected number of proteins among the hox5 polypeptides of HDZip class I or homologs thereof may Also understand a Trp tail. A Trp tail according to that defined herein is the last 10 amino acids of the C-terminus of the protein comprising at least one Trp residue (see Figure 2). Examples of HOX5 polypeptides of HDZip class I or homologs thereof (encoded by the polynucleotide sequence with accession number in parentheses) are given in Table A. It should be understood that the sequences fall within the definition of "polypeptides" Hox5 of HDZip class I or homologs thereof "should not be limited to the sequences provided in Table A, but any polypeptide comprising from N-terminal to C-terminal: (i) an acidic picture; and (ii) a class I homeodomain; and (iii) a leucine closure with more than 5 heptates may be suitable for use in carrying out the methods of the invention. Hox5 polypeptides of HDZip class I or homologs thereof have a DNA binding activity, preferably at half-sites of five 5 bases that are spliced in a central position, CAA (A / T) ATTG, in accordance with detected in trials of a yeast hybrid (Meijer et al. (2000) Mol Gen Genet 263: 12-21). In transient assays in rice cell suspensions, co-bombardment of a Hox 5 HDZip class I polypeptide with the GUS reporter gene resulted in an increased number of stained spots, which they were also more dense in color (Meijer et al, supra). This assay is useful for demonstrating the activating function of the hox5 polypeptides of HDZip class I or homologs. NRT polypeptides and homologs thereof and their coding nucleic acids useful in the methods of the invention The term "NRT or homologue thereof" as defined herein refers to a polypeptide comprising (i) an MFS_1 domain (Pfam access PF07690, InterPro access IPR01 1701) followed by (ii) a transmembrane domain. An example is provided in Figures 6 (a) and (b). Preferably, the NRT protein or homologue thereof has an NRT activity, for example high affinity nitrate transport, and does not comprise a PRT2 domain (Pfam access PF00854, InterPro access IPR000109). Preferably, the NRT protein or homologue thereof comprises a signature sequence 1 (SEQ ID NO: 57): (N / S) (Y / P) (T / G / S / A) W (I / V / L ) (F / L / T) (V / A / F / L) (L / V / M / l) (L / T / l / A / N) YG (Y / F) (S / C / T) (M / F / Y) G (V / I) EL (T / S) (T / I / V) (D / G / N) N (V / I / N) (I / V) (A / S) / H / V) (E / Q / G) Y. Further preferably, the NRT protein or homologue thereof comprises one or more of the following: signature sequence 2 (SEQ ID NO: 58): LG (P / A) RYG (C / T) AF (L / S) ); Signature sequence 3 (SEQ ID NO: 59): STFAA (A / R) PL (V / I) (P / V) (I / L / V) IR (D / E) NL (N / D) (L / P); signature sequence 4 (SEQ ID NO: 60): VRF (L / M) IGF (S / C) LA; Signature sequence 5 (SEQ ID NO: 61): FVSC (Q / R) YW (M / T) S (T / V) (M / S) (F / M). More preferably, the NRT protein or homologue thereof comprises one or more of the following: signature sequence 6 (SEQ ID NO: 62): K (A / Q / S / M / H / T) D (I / V) GNAGVASV (S / T) G (S / A) I (F / L) SR (L / G); Signature sequence 7 (SEQ ID NO: 63): NG (L / T / C) A (A / G) GWG; Signature sequence 8 (SE ID NO: 64): G (A / S) G (L / V / Q) TQ (L / P) (L / V / I) (F / E) F (T / S / D) (S / T) (S / A / T). More preferably, the NRT protein is in accordance with that represented in SEQ ID NO: 53. Transmembrane domains are approximately 15 to 30 amino acids long and are usually made up of hydrophobic residues that form an alpha helix. They are usually predicted on the basis of hydrophobicity (eg, Klein et al., Biochim Biophys, Acta 815, 468, 1985, or Sonnhammer et al., In J. Glasgow, T. Littlejohn, F. Major, R. Lathrop , D. Sankoff, and C. Sensen, editors, Minutes of the Sixth International Conference on Intelligent Systems for Molecular Biology, page 175-182, Menlo Park, CA, 1998. AAAI Press.).

Alternatively, the homolog of a NRT protein has in increasing order of preference a global sequence identity of 50%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80% , 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97 %, 98% or 99% with the amino acid represented by SEQ ID NO: 53. The global sequence identity is determined using a global alignment algorithm, such as the Needleman Wunsch algorithm in the GAP program (GCG Wisconsin Package, Accelrys) , preferably with default parameters. The various structural domains in an NRT protein can be identified using specialized databases, for example SMART (Schultz et al (1998) Proc. Nati, Acad. Sci. USA 95, 5857-5864; Letunic et al. (2002) Nucleic Acids Res 30, 242-244, http://smart.embl-heidelberg.de/), InterPro (Mulder et al., (2003) Nucí Acids, Res. 31, 315-318, http: // www. ebi.ac.uk/interpro/), Prosite (Bucher and Bairoch (1994), A generalized profile syntax for motifs of biomolecular sequences and their function and automatic sequence interpretation. (En) ISMB-94; Proceedings of the second conference International on Intelligent Systems for Molecular Biology: Altman R., Brutlag D., Karp P., Lathrop R., Searls D., Eds., pp53-61, AAAI Press, Menlo Park, Hulo et al., Nuci. Acids Res. 32: D134-D137, (2004), http://www.expasy.org/prosite/) or Pfam (Bateman et al., Nucleic Acids Research 30 (1): 276-280 (2002), http: //www.sanger.ac.uk/ Software / Pfam /). Methods for the search and identification of NRT homologs are within the reach of people with knowledge in the field. Such methods comprise the comparison of the sequences represented by SEQ ID NO: 1 or 2, in a computer readable format, consequences available in public databases such as MIPS (http: // mips. Gsf. De /), GenBank (http: // www. ncbi.nlm.nih.gov/Genbank/index.html) or EMBL Nucleotide Sequence Datábase (http: // www.ebi.ac.uk/ embl / inde.html), using algorithms well known in the art for sequence alignment or comparison, such as GAP (Needleman and Wunsch, J. Mol. Biol. 48; 443-453 (1970)), BESTFIT (using the local homology algorithm of Smith and Waterman (Advances in Applied Mathematics 2; 482-489 (1981))), BLAST (Altschul, SF, Gish, W., Miller , W., Myers, EW &Lipman, DJ., J. Mol. Biol. 215: 403-410 (1990)), FASTA and TFASTA (WR Pearson and DJ Lipman Proc. Nati. Acad. Sci. USA 85: 2444-2448 (1988)). The software to perform a BLAST analysis is publicly available through the National Center for Biotechnology Information [National Center for Information on Biotechnology] (NCBI).

Examples of proteins that fall within the definition of "NRT polypeptide or a homologue thereof" include rice proteins and proteins from other species such as Zea mays, Phragmi tes a ustralis, Hordeum vulgare, Tri ticum aestivum, Brassica napus, Lycopersicon esculen tum, Nicotiana tabacum, Daucus carota, Populus tremulus, Lotus japonica, Prunus pérsica, Glycine max and Arabidopsis thaliana, among others. A non-limiting list of examples of NRT proteins is provided in Table 1 of Example 14 herein. It is contemplated, however, that NRT proteins from other plant taxa, such as mosses or ferns, may also be useful in the methods of the present invention. For example, the Physcomi moss trella pa tens possesses at least 5 NRT proteins (access numbers GenBank BAD00097, BAD00098, BAD00099, BAD00100, BAD00101). It will be understood that the term "NRT polypeptide or a homologue thereof" is not limited to the sequence represented by SEQ ID NO: 53 or to the sequences given in Table I, but any polypeptide that meets the criteria of understanding a domain Functional MFS_1 and one or more conserved signature sequences of SEQ ID NO: 57 to 64, and a transmembrane domain located C-terminally of the MFS_1 domain in accordance with that defined above; or having at least a sequence identity of 50% with the sequence SEQ ID NO: 53, may be suitable for use in the methods of the invention. To determine the transport activity of NRT, the nitrate absorption test is carried out in accordance with that described by Tong et al. (Plant J. 41, 442-450, 2005). In summary, the NRT protein of interest is expressed in Xenopus oocytes, and the uptake of nitrate enriched with 15N is measured. If required, a nar2 gene can be co-expressed to increase nitrate transport. Alternatively, the activity of an NRT protein or homologue thereof can be assayed by expression of the NRT protein or homologue thereof under the control of a GOS2 promoter in the Nipponbare cultivar of Oryza sa tiva, which results in plants with a increased soil biomass and / or increased seed yield compared to the corresponding wild type plants. This increase in seed yield can be measured in several ways (for example, as an increase in the total weight of seeds, number of seeds filled or total number of seeds, such as an increase in the harvest index or as an increase in flowers by A protein of NRT or homologue thereof is encoded by a nucleic acid / NRT gene.Therefore, the term "nucleic acid / NRT gene" as defined herein is a nucleic acid / gene encoding a NRT protein or a homologue thereof compliance with what is defined above. YEP16 Polypeptides and Homologs and Their Encoding Nucleic Acids Useful in the Methods of the Invention The term "YEP16 polypeptide" refers to the sequence of SEQ ID NO: 128. A homologue of a YEP16 polypeptide refers to any shared amino acid sequence, in increasing order of preference, a sequence identity of at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% with the amino acid sequence of SEQ ID NO: 128. Reference herein to a "nucleic acid encoding a YEP16 polypeptide or a homologue thereof" therefore refers to any nucleic acid sequence encoding a polypeptide YEP16 or a homologue thereof "therefore refers to any nucleic acid sequence encoding a YEP16 polypeptide in accordance with that defined above or any nucleic acid encoding a YEP16 polypeptide in accordance with that defined above or any nucleic acid coding It assigns a counterpart of YEP16 in accordance with what is defined above. Group I hairy type kinases and homologues thereof and their encoding nucleic acids useful in the methods of the invention The term "Group I hairy type kinase or homologue thereof" in accordance with that defined above refers to a polypeptide having: (i) a sequence identity of at least 77% with the amino acid sequence represented by SEQ ID NO: 147; and (ii) motif I: R / H / V / N / Q E / G LK G / N and motif II: K Q / N CXXX G / A / S, where X can be any amino acid. A polypeptide that meets the requirements mentioned above allows a hairy-type kinase of group I to be distinguished from kinases from other groups. A "Group I hairy kinase or a homologue thereof" which falls within the above definition can easily be identified using routine techniques well known to those skilled in the art. For example, a polypeptide having an identity of at least 77% with the amino acid represented by SEQ ID NO: 174 can be easily established by sequence alignment. Methods for sequence alignment for comparison are well known in the art, such methods include GAP, BESTFIT, BLAST, FASTA and TFASTA. GAP uses the algorithm of Needleman and Wunsch (J. Mol. Biol. 48: 443-453, 1970) to find the alignment of two complete sequences that maximizes the number of correspondences and minimizes the number of spaces. The BLAST algorithm calculates the percent identity of sequences and performs a statistical analysis of the similarity between the two sequences. The software to perform a BLAST analysis is publicly available through the National Center for Biotechnology Information.

Biotechnology]. A hairy type kinase or a homologue thereof having an identity of at least 77% with the amino acid represented by SEQ ID NO: 147 can be easily identified by aligning a search amino acid sequence with kinase sequences of hairy type of known group I (see, for example, the alignment shown in Figure 14) using, for example, the VNTI AlignX multiple alignment program, based on a modified W clustal algorithm (InforMax, Bethesda, MD, http: // www. informaxinc.com), with default settings for a space opening penalty of 10 and a space extension of 0.05. A person skilled in the art will also easily identify sequences having a motif I: R / H / V / N / QE / G LK G / N and motif II: KQ / N CXXX G / A / S, where X it can be any amino acid. This can be achieved by performing an alignment and looking for homologous regions. Table 1 below shows the motif I: R / H / V / N / QE / G LK G / N and motif II: KQ / N CXXX G / A / S (where X can be any amino acid) as found in the sequence of SEQ ID NO: 174 and the corresponding motifs in homologous sequences. The overall percentage identity shown in Table 1 is when comparing SEQ ID NO: 174 with the access numbers shown in the Table (full length sequences to full length sequence).

Table 1: Conserved motifs found in Group I hairy type kinases and their homologues Examples of polypeptides that fall within the definition of a "hairy type kinase or a homologue thereof" include the following sequences: SEQ ID NO: 147, a rice hairy-like gamma kinase (accession number NCBI AB059621); SEQ ID NO: 149 (accession number NCBI AK058276) a hairy-like kinase of rice; SEQ ID NO: 151 (accession number NCBI AK099599) a hairy-like kinase of rice; SEQ ID NO: 153, a hairy type alpha kinase of Arabidopsis thaliana (accession number NCBI At5g26750); SEQ ID NO: 155, a hairy-like gamma kinase from Arabidopsis thaliana (accession number NCBI At3g05840); SEQ ID NO: 157, a hairy-like alpha kinase of Arabidopsis thaliana (accession number NCBI CAA48538.1); SEQ ID NO: 159, a hairy type epsilon kinase from Arabidopsis thaliana (accession number NCBI At5gl4640); SEQ ID NO: 161, a hairy-like gamma kinase from Arabidopsis thaliana (accession number NCBI CAA73247.1); SEQ ID NO: 163 of corn (access number NCBI AY103545); SEQ ID NO: 165 of corn (number of access NCBI AY108486.1); SEQ ID NO: 167 of Medicago (access number NCBI CAA48472.1); SEQ ID NO: 169 of Medicago (access number NCBI CAA48474.1); SEQ ID NO: 171 of Medicago (access number NCBI CAA48473.1); SEQ ID NO: 173 of tobacco (access number NCBI CAA54803.1); SEQ ID NO: 175 a prediction of hairy-like kinase protein from Tri ticum aestivum (accession number NCBI AAM77397.1); SEQ ID NO: 177 of Petunia hybrida (access number NCBI CAA58594.1). The term "hairy type kinase or a homologue thereof, is not limited to the sequences represented by SEQ ID NOs mentioned in the preceding paragraph but any polypeptide that meets the criteria of having: (i) a sequence identity of at least 77% with an amino acid sequence represented by SEQ ID NO: 174, and (ii) motif I: R / H / V / N / QE / G LK G / N and motif II: KQ / N CXXX G / A / S, wherein X can be any amino acid, would be suitable for use in the methods of the present invention Hairy type kinases, as the name suggests, have a kinase activity One assay for glycogen synthase kinase-3 (GSK) -3), the animal homolog, is reported in The Biochemical Journal, Vol. 303 (Pt3), Nov. 1, 1994, pages 701-704 (Stambolic and Woodgett). Sequences useful in the methods of the present invention are not limited to nucleic acids hox5 of leucine closure of homeodomain (HDZip) of class I mentioned above and polypeptides; or to the aforementioned NRT polypeptides and their encoding nucleic acids; or to the YEP16 polypeptides mentioned above and their encoding nucleic acids; or the hairy-type kinases of group I mentioned above and their coding polypeptides. The methods according to the present invention can also be carried out using homeodomain leucine closure (HDZip) class I polypeptide variants encoding or homologs thereof; or by using nucleic acid variants that encode NRT polypeptides or homologs thereof; or by the use of nucleic acid variants encoding YEP16 polypeptides and homologs thereof; or by the use of nucleic acid variants that code for group I hairy type kinases and homologs thereof. Examples of such variants include portions, hybridization sequences, allelic variants, splice variants and variants obtained by gene recombination. A portion can be prepared, for example, by making one or more deletions to a nucleic acid. The portions can be used in isolation or they can be fused with other coding (or non-coding) sequences to produce, for example, a protein which combines several activities. When fused with other coding sequences, the resulting polypeptide produced at translation may be greater than predicted for the portion. When the sequence useful in the methods of the present invention is a hox5 of HDZip class I, the portion encodes a polypeptide comprising from the N-terminus to the C-terminus: (i) an acidic box; (ii) a class I homeodomain; and (iii) a leucine closure with more than 5 heptates. Preferably, the portion is a portion of one of the nucleic acids provided in Table A. Most preferably, the portion is a portion of a nucleic acid in accordance with that represented by SEQ ID NO: 1. When the sequence useful in the methods of the present invention is a nucleic acid encoding an NRT, the portion refers to a piece of DNA encoding a polypeptide comprising an MFS_1 domain and a transmembrane domain located C-terminally of the MFS_1 domain. . Preferably, the portion comprises one or more of the signature sequences defined above. Preferably, the portion is a portion of one of the nucleic acids provided in Table I. More preferably, the portion of a nucleic acid is in accordance with that represented by SEQ ID NO: 52. When the sequence useful in the methods of the present invention is a nucleic acid encoding YEP16, the portion refers to a DNA part encoding a YEP16 polypeptide or a homologue thereof having, in increasing order of preference, at least 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575 consecutive nucleotides of the nucleic acid sequence represented by SEQ ID NO: 127 or SEQ ID NO: 129 or wherein a portion has in increasing order of preference, at least 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525 , 550, 575 consecutive nucleotides of a nucleic acid sequence encoding a YEP16 polypeptide or a homologue thereof. Preferably, the portion is a portion of a nucleic acid in accordance with that represented by SEQ ID NO: 127 or SEQ ID NO: 129. When the sequence useful in the methods of the present invention is a hairy type kinase of group I, the portion refers to a part of DNA encoding hairy-like kinase of at least 1,200 nucleotides in length and said portion encoding a polypeptide having: (i) a sequence identity of at least 77% with the amino acid sequence represented by SEQ ID NO: 147; and (ii) has motif I: R / H / V / N / Q E / G LK G / N and motif II: K Q / N CXXX G / A / S, where X can be any amino acid. Preferably, the portion is a portion of a nucleic acid in accordance with that represented by any of SEQ ID NO: 146, SEQ ID NO: 148, SEQ ID NO: 150, SEQ ID NO: 152, SEQ ID NO: 154, SEQ ID NO: 156, SEQ ID NO: 158, SEQ ID NO: 160, SEQ ID NO: 162, SEQ ID NO: 164, SEQ ID NO: 166, SEQ ID NO: 168, SEQ ID NO: 170, SEQ ID NO: 172, SEQ ID NO: 174 and SEQ ID NO: 176. The invention therefore offers a method for improving the growth characteristics of a plant comprising the modulation of the expression in a plant of a portion of a nucleic acid encoding a hox5 polypeptide of homeodomain leucine closure (HDZip) of class I or a homolog thereof; or comprising modulating the expression in a plant of a portion of a nucleic acid encoding a NRT polypeptide or a homologue thereof; or comprising the modulation of the expression in a plant of a portion of a nucleic acid encoding a YEP16 polypeptide or a homologue thereof; or comprising the modulation of the expression in a plant of a portion of a nucleic acid encoding a group I hairy kinase or a homologue thereof. Another variant of nucleic acid is a nucleic acid capable of hybridizing under conditions of reduced stringency, preferably under stringent conditions, to a nucleic acid encoding a nucleic acid / hox5 gene of HDZip class I or a homologue thereof; or with a nucleic acid encoding a NRT polypeptide or a homologue thereof; or with a nucleic acid encoding a YEP16 protein or a homologue thereof; or with a nucleic acid encoding a group I hairy kinase or a homologue thereof. The term "hybridization" according to the definition herein is a process in which sequences of substantially homologous complementary nucleotides are joined together. The hybridization process can occur entirely in solution, that is, both complementary nucleic acids are in solution. The hybridization process can also occur with one or more of the complementary nucleic acids immobilized in a matrix, for example magnetic beads, Sepharose beads, or any other resin. The hybridization process may also occur with one or more of the complementary nucleic acids immobilized on a solid support, such as a nitrocellulose or nylon membrane or immobilized for example by means of photolithography, for example on a siliceous glass support (this last known as sets or micro-sets of nucleic acid or as nucleic acid chips). In order to allow hybridization, the nucleic acid molecules are generally thermally or chemically denatured to fuse a double chain into two individual chains and / or to remove hair pins or other secondary structures of single-stranded nucleic acids. The level of strictness of the hybridization is influenced by conditions such as temperature, salt concentration, ionic strength and hybridization buffer composition. "Strict hybridization conditions" and "stringent hybridization wash conditions" in the context of nucleic acid hybridization experiments such as Southern and Northern hybridizations are sequence dependent and are different in different environmental parameters. The person skilled in the art is aware of several parameters that can be altered during hybridization and washing and that will either maintain or change the conditions of strictness. Tm is the temperature under defined ionic strength and pH, in which 50% of the target sequences are hybridized in a perfect match probe. Tm depends on the conditions of the solution and on the base composition and the length of the probe. For example, longer sequences hybridize specifically at higher temperatures. The maximum rate of hybridization is obtained from about 16 ° C to about 32 ° C below Tm. The presence of monovalent cations in the hybridization solution reduces the electrostatic repulsion between the two nucleic acid strands thereby promoting the formation of hybrids. This effect is visible in the case of sodium concentrations of up to 0.4 M. Formamide reduces the fusion temperature of DNA-DNA duplexes and DNA-RNA with 0.6 to 0.7 ° C for each percent of formamide, and in addition to 50% of formamide allows the realization of hybridization at temperatures between 30 and 45 ° C, when the hybridization rate will be reduced. Mismatches between base pairs reduce the hybridization rate and the thermal stability of the duplexes. On average and for large probes, the Tm decreases approximately 1 ° C per% lack of base correspondence. The Tm can be calculated using the following equations, according to the types of hybrids: 1. DNA-DNA hybrids (Meinkoth and Wahl, Anal. Biochem., 138: 267-284, 1984): Tra = 81.5 ° C + 16.6xlog [Na + ] a + 0.41x% [G / Cb] -500x [Lc] _1 - 0.61 x% formamide 2. DNA-RNA or RNA-RNA hybrids: Tm = 79.8 + 18.5 (log? 0 [Na +] a) + 0.58 ( % G / Cb) + 11.8 (% G / C) 2 - 820 / Lc 3. Oligo-DNA hybrids or oligo-RNAd: For < 20 nucleotides: Tm = 2 (/ n) For 20-35 nucleotides: Tm = 22 + 1.46 (/ n) ao for another monovalent cation, but only accurate in the range of 0.01-0.4 M. only exact for% GC in the range from 30% to 75%. c L = length of duplex in base pairs. d Oligo, oligonucleotide; / n, effective length of primer = 2x (No. of G / C) + (No. of A / T). Note: for each 1% of formamide, the Tm is reduced by approximately 0.6 to 0.7 ° C, while the presence of 6 M urea reduces the Tm by approximately 30 ° C. The specificity of the hybridization typically depends on the post-hybridization washes. To remove the bottom that results from non-specific hybridization, samples are washed with diluted salt solutions. Critical factors such as washes include the ionic strength and the temperature of the final wash solution: the lower the salt concentration and the higher the wash temperature, the higher the wash stringency level. The washing conditions are typically carried out at or below the level of stringency of the hybridization. In general, stringent conditions suitable for nucleic acid hybridization assays or gene amplification detection methods are established in accordance with the above. Conditions of greater or lesser strictness can also be selected. In general, low stringency conditions are selected to be approximately 50 ° C below the thermal melting point (Tm) for the specific sequence at the defined ionic strength and established pH. Medium stringency conditions are when the temperature is 20 ° C below Tm, and high stringency conditions are when the temperature is 10 ° C below Tm. For example, strict conditions are those that are at least as strict as, for example, conditions A-L; and reduced stringency conditions are at least as strict, for example, M-R conditions. A non-specific binding can be controlled using any of several known techniques such as for example blocking the membrane with solutions containing protein, additions of RNA, DNA, and heterologous SDS to the hybridization buffer, and RNase treatment. Examples of hybridization and washing conditions are presented in Table 2 below. Table 2: Examples of hybridization and washing conditions > or 65 ° C 4xSSC; or 65 ° C; equal to 45 ° C, 4xSSC and 50% G DNA: DNA 50 formamide lxSSC Th *; H DNA: DNA < 50 Th *; 4xSSC 4xSSC > or 67 ° C 4xSSC; or equal to 45 ° C, 4xSSC and 50% 67 ° C, I DNA: RNA 50 formamide lxSSC Tj *; J DNA: RNA < 50 Tj *; 4xSSC 4xSSC > or 70 ° C 4xSSC; or equal to 40 ° C, 6xSSC and 50% 67 ° C; K RNA: RNA 50 formamide lxSSC TI *; L RNA: RNA < 50 IT *; 2xSSC 2xSSC > or 50 ° C 4xSSC; or equal to 40 ° C, 6xSSC and 50% 50 ° C; M DNA: DNA 50 formamide 2xSSC Tn *; 6 N DNA: DNA < 50 Tn *; 6 xSSC xSSC > or 55 ° C 4xSSC; or equal to 42 ° C, 6xSSC and 50% 55 ° C; 0 DNA: RNA 50 formamide 2xSSC; Tp *; P DNA: RNA < 50 Tp *; 6xSSC dxSSC > or 60 ° C 4xSSC; or equal to 45 ° C, 6xSSC and 50% 60 ° C; Q AR: RNA 50 formamide 2xSSC Tr *; R RNA: RNA < 50 Tr *; 4 xSSC 4xSSC F "Hybrid length" is the anticipated length of the hybridizing nucleic acid. When nucleic acids of known sequence are hybridized, the hybrid length can be determined by sequence alignment and identification of the conserved regions described herein, t SSPE (1 x SSPE is 0.15 M NaCl, 10 mM NaH2P04 and 1.25 mM EDTA, pH 7.4) can be replaced by SSC (lxSSC is 0.15 M NaCl and mM sodium citrate) in the wash and hybridization buffers; the washes are carried out for 15 minutes after the hybridization is finished. Hybridizations and washings may additionally include 5 x Denhardt's reagent, 0.5-1.0% SDS, 100 μg / ml Denatured salmon sperm DNA, denatured, 0.5% sodium pyrophosphate and up to 50% formamide. * Tb-Tr: Hybridization temperature for hybrids anticipated to be less than 50 base pairs in length should be 5-10 ° C less than the melting temperature Tm of the hybrids; Tm is determined in accordance with the equations mentioned above. The present invention also encompasses the substitution of one or more hybrid partners of DNA or RNA with either a PNA or a modified nucleic acid. For the purposes of defining the level of strictness, reference can be made to Sambrook et al. (2001) Molecular Cloning: a laboratory manual, 3rd edition Cold Spring Harbor Laboratory Press, CSH, New York or Current Protocols in Molecular Biology, John Wiley & Sons, N. Y. (1989). When the sequence useful in the methods of the present invention is a hox5 of HDZip class I, the hybridization sequence encodes a polypeptide comprising from the N-terminus to the C-terminus: (i) an acidic cadre; and (ii) a class I homeodomain; and (iii) a leucine closure with more of 5 heptad. Preferably, the hybridization sequence is capable of hybridizing under conditions of reduced stringency, preferably under stringent conditions, to one of the nucleic acids provided in Table A or a portion thereof as defined herein. More preferably, the portion is a portion of a nucleic acid represented by SEQ ID NO: 1. When the sequence useful in the methods of the invention is a nucleic acid encoding a NRT polypeptide or homologue thereof, the hybridization sequence is a nucleic acid / gene capable of hybridizing under conditions of reduced stringency, preferably under stringent conditions, with a nucleic acid / NRT gene encoding a polypeptide comprising an MFS_1 domain and a transmembrane domain located C-terminally of the MFS_1 domain, and preferably also one or more signature sequences defined above. Preferably, the hybridization sequence is a sequence that is capable of hybridizing to a nucleic acid given in Table I of Example 14 or to a portion of any of the nucleic acids provided in Table I, a portion being in accordance with that defined above. . More preferably, the hybridization sequence is capable of hybridizing to SEQ ID NO: 52. When the sequence useful in the methods of the present invention is a nucleic acid encoding a polypeptide YEP16 or homologue thereof, the hybridization sequence is a nucleic acid sequence capable of hybridizing under conditions of reduced stringency, preferably under stringent conditions, to a nucleic acid sequence encoding a YEP16 polypeptide or a homologue thereof. Preferably, the hybridization sequence is capable of hybridizing under conditions of reduced stringency to a nucleic acid in accordance with that represented by SEQ ID NO: 127 or SEQ ID NO: 129. When the nucleic acid useful in the methods of the present invention is a nucleic acid encoding a Group I hairy kinase, the hybridization sequence is a nucleic acid capable of hybridizing under conditions of reduced stringency, preferably under stringent conditions, with a nucleic acid / gene encoding group hairy-like kinase I according to that defined above, said hybridization sequence encodes a polypeptide having: (i) a sequence identity of at least 77% with the amino acid sequence represented by SEQ ID NO: 147; and (ii) motif I: R / H / V / N / Q E / G LK G / N and motif II: K Q / N CXXX G / A / S, where X can be any amino acid. The hybridization sequence is at least 1,200 nucleotides in length. Preferably, the hybridization sequence is capable of hybridizing to a nucleic acid in accordance with that represented by any of SEQ ID.

NO: 146, SEQ ID NO: 148, SEQ ID NO: 150, SEQ ID NO: 152, SEQ ID NO: 154, SEQ ID NO: 156, SEQ ID NO: 158, SEQ ID NO: 160, SEQ ID NO: 162, SEQ ID NO: 164, SEQ ID NO: 166, SEQ ID NO: 168, SEQ ID NO: 170, SEQ ID NO: 172, SEQ ID NO: 174 and SEQ ID NO: 176. The invention therefore offers a method for improving the growth characteristics of plants, comprising modulating the expression in a plant of a nucleic acid capable of hybridizing under conditions of reduced stringency, preferably under stringent conditions with a nucleic acid encoding a hox5 polypeptide of leucine closure of homeodomain (HDZip) of class I or a homolog thereof; or comprising the modulation of the expression in a plant of a nucleic acid capable of hybridizing under conditions of reduced stringency, preferably under stringent conditions with a nucleic acid encoding a NRT polypeptide or a homologue thereof; or comprising modulating the expression in a plant of a nucleic acid capable of hybridizing under conditions of reduced stringency, preferably under stringent conditions with a nucleic acid encoding a YEP16 polypeptide or homolog thereof; or comprising the modulation of the expression in a plant of a nucleic acid capable of hybridizing under conditions of reduced stringency, preferably under stringent conditions to a nucleic acid encoding a Hairy type kinase of Group I or a homologue thereof. The nucleic acids or variants thereof can be derived from any natural or artificial source. The nucleic acid / gene or variant thereof can be isolated from a microbial source, such as for example yeast or fungi, or from a plant, algae or animal (including human). The nucleic acid can be modified from its native form in composition and / or genomic environment through deliberate human manipulation. The nucleic acid is preferably of plant origin, either from the same species of plant (for example from the same species in which it is to be introduced) or from a different plant species. The nucleic acid can be isolated from a monocotyledonous species, preferably from the family Poaceae, preferably from the genus Oryza, more preferably from Oryza sa tiva. The nucleic acid can be isolated from a dicotyledonous species, preferably of the Brassicaceae family, with additional preference of Arabidopsis thaliana. The expression of a nucleic acid can be modulated by the introduction of a genetic modification (preferably at the locus of the gene in question). The locus of a gene according to the definition herein means a genomic region that includes the gene of interest and 10 kb upstream or downstream of the coding region.

The genetic modification can be introduced, for example, by any of the following methods (or several of them): activation of T-DNA, TILLING, site-directed mutagenesis, directed evolution and homologous recombination or by introduction and expression in a plant of a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof; or by the introduction and expression in a plant of a nucleic acid encoding an NRT or a homologue thereof; or by introducing and expressing in a plant a nucleic acid encoding a YEP16 or a homologue thereof; or by the introduction and expression in a plant of a nucleic acid encoding a Group I hairy kinase or a homologue thereof. After the introduction of the genetic modification, a selection step for the modulated expression of the nucleic acid follows, said modulation in expression provides plants having improved growth characteristics, especially increased yield. Labeling of T-DNA activation (Hayashi et al., Science (1992) 1350-1353) includes the insertion of T-DNA, which usually contains a promoter (can also be a translation enhancer or an intron) in the region genomic of the gene of interest or 10 kg upstream or downstream of the coding region of a gene in a configuration such that the promoter directs the expression of the focused gene. Typically, regulation of the expression of the gene targeted by its natural promoter is disrupted and the gene falls under the control of the newly introduced promoter. The promoter is typically integrated into a T-DNA. This T-DNA is inserted randomly into the plant genome, for example, through infection with Agrobacterium and involves the overexpression of genes near the inserted T-DNA. The resulting transgenic plants show dominant phenotypes due to overexpression of genes near the introduced promoter. The promoter to be introduced can be any promoter capable of directing the expression of a gene in the desired organism, in this case a plant. For example, constitutive, tissue preferred, preferred promoters for cellular and inducible types are all suitable for use in T-DNA activation. A genetic modification can also be introduced into the locus of the gene in question using the TILLING technique (Targeted Induced Local Lesions In Genomes). It is a useful mutagenesis technology to generate and / or identify and isolate mutagenized variants. TILLING also allows the selection of plants that carry such mutant variants. These mutant variants may present up to a higher activity than the activity presented by the gene in its form natural. TILLING combines high-density mutagenesis with high-throughput screening methods. The steps typically followed in TILLING are the following: (a) mutagenesis of EMS (Redei GP and Koncz C (1992) in Methods in Arabidopsis Research, Koncz C, Chua NH, Schell J, eds. Singapore, World Scientific Publishing Co., pp 16-82; Feldmann et al., (1994) In Meyerowitz EM, Somerville CR, eds, Arabidopsis, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, pp. 137-172; Lightner J and Caspar T (1998) In J Martinez-Zapater, Salinas J, eds, Methods on Molecular Biology, Vol. 82. Humana Press, Totowa, NJ, pp 91-104); (b) DNA preparation and combination of individuals; (c) amplification by polymerase chain reaction of a region of interest; (d) denaturation and fusion to allow the formation of heteroduplexes; (e) DHPLC, wherein the presence of a heteroduplex in a group is detected in the form of an extra peak in the chromatogram; (f) identification of the mutant individual; and (g) sequencing the mutant polymerase chain reaction product. Methods for TILLING are well known in the art (McCallum et al., (2000) Nat Biotechnol 18: 455-457, reviewed by Stemple (2004) Nat Rev Genet 5 (2): 145-50). Site-directed mutagenesis can be used to generate variant nucleic acids. Several methods are available to achieve site-directed mutagenesis, the most common being methods based on polymerase chain reaction (Current Protocols in Molecular Biology, Wiley Eds http: //www.4ulr.com/products/currentprotocols/index.html). Targeted evolution or gene recombination can also be used to generate nucleic acid variants. This consists of iterations of DNA recombination followed by appropriate screening and / or selection to generate variants having a modified biological activity (Castle et al., (2004) Science 304 (5674): 1151-4, North American patents Nos. 5, 81, 1,238 and 6,395,547). The activation of T-DNA, TILLING, site-directed mutagenesis and directed evolution are examples of technologies that allow the generation of novel alleles and variants. Homologous recombination allows the introduction into a genome of a selected nucleic acid at a defined selected position. Homologous recombination is a standard technology routinely used in the biological sciences for lower organisms such as yeast and Physcomi moss trella. Methods for homologous recombination in plants have been described not only for model plants (Offringa et al (1990) EMBO J 9 (10): 3077-84) but also for crop plants, for example rice (Terada et al. (2002) Nat Biotech 20 (10): 1030-4; Lida and Terada (2004) Curr Opin Biotech 15 (2): 132-8). The nucleic acid to focus does not have to be focused on the locus of the gene in question, but it can be introduced, for example, into regions of high expression. The nucleic acid to be targeted can be an improved allele used to replace the endogenous gene or it can be introduced in addition to the endogenous gene. A preferred method for introducing a genetic modification is to introduce and express in a plant a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof; or introducing or expressing in a plant a nucleic acid encoding an NRT or a homologue thereof; or introducing and expressing in a plant a nucleic acid encoding a YEP16 or a homologue thereof; or introducing and expressing in a plant a nucleic acid encoding a Group I hairy kinase or a homologue thereof. The nucleic acid to be introduced into a plant can be a full-length nucleic acid or it can be a portion of a hybridization sequence according to that defined above. When the sequence useful in the methods of the present invention is a YEP16 polypeptide or a homologue thereof, focusing on a plastic is preferred; Methods for targeting plastid proteins are well known in the art, such as the use of transit peptides for such approach. Table 3 below shows examples of suitable transit peptides for targeting any YEP16 polypeptide or homologue from it to a plastid, preferably a chloroplast. The use of the native transit peptide to the sequence of YEP16 polypeptides of SEQ ID NO: 128 is preferred, said native transit peptide is shown in SEQ ID NO: 131. SEQ ID NO: 130 represents the YEP16 polypeptide together with its peptide of native transit for approach to the chloroplast (SEQ ID NO: 129 represents the nucleic acid sequence encoding the amino acid sequence of SEQ ID NO: 130). The use of the native transit peptide as shown in SEQ ID NO: 131 is more preferred to focus a YEP16 polypeptide in accordance with that represented by SEQ ID NO: 128, even though any transit peptide can be used with any YEP16 polypeptide. or its counterpart. Table 3: Examples of transit peptide sequences useful in the approach of amino acids towards plastids "Homologs" of a protein encompass peptides, oligopeptides, polypeptides, proteins and enzymes having substitutions, deletions and / or amino acid insertions relative to the unmodified protein in question and having a biological and functional activity similar to the unmodified protein from which it is derived. To produce such homologs, amino acids of the protein can be replaced by other amino acids that have similar properties (such as a hydrophobicity, hydrophilicity, antigenicity, propensity to form or break down helical structures or similar β-sheet structures). Tables of conservative substitutions are well known in the art (see, for example Creighton (1984) Proteins, W. H. Freeman and Company and Table 4 below). Homologs useful in the methods according to the present invention are preferably polypeptides having, in increasing order preferably at least 30%, 40%, 50%, 60%, 70%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% or more of sequence identity or similarity (functional identity) with the sequences mentioned herein as useful in the methods of the present invention, for example the sequences provided in Table A and I and here. The term "homologous" also encompasses two special forms of homology that include orthologous sequences and paralogical sequences that encompass evolutionary concepts used to describe ancestral gene relationships. The term "paralog" refers to gene duplications within the genome of a species that leads to paralogical genes. The term "ortholog" refers to homologous genes in different organisms due to speciation. Orthologs, for example in species of monocotyledonous plants can be easily found by carrying out what is known as a reciprocal BLAST search. Taking the example of finding an orthologous or paralog of a hox5 nucleic acid of HDZip class I or hox5 polypeptide of HDZip class I, this can be done through a first Blast that includes submitting Blast to the sequence in question ( for example, SEQ ID NO: 1 or SEQ ID NO: 2) against any sequence database, such as the publicly available NCBI database that can be found at: http: //www.ncbi.nlm.nih .gov. BLASTN or TBLASTX can be used when starting from the sequence of nucleotides, either BLASTP or TBLASTN when starting from the protein, with standard default values. The BLAST results can be filtered. The full length sequences of any of the filtered results or the unfiltered results are then subjected again to BLAST (second BLAST) against the sequences of the organism from which the sequence in question is derived. The results of the first BLAST and the second BLAST are then compared. When the results of the second BLAST provide as a result with the highest similarity a hox5 nucleic acid of HDZip class I or a hox5 polypeptide of HDZip class I, then a paralog has been found, if it comes from the same organism as in the case of the sequence used in the first BLAST. If it originates from an organism other than the organism of the sequence used in the first BLAST, then an ortholog has been found. In the case of large families, ClustalW can be used, followed by a neighbor union tree to help visualize the group. The same procedure can also be used to find nucleic acid orthologs and paralogs that encode an NRT and NRT polypeptides; and to find orthologs and paralogs of nucleic acids encoding YEP16 and YEP16 polypeptides; and to find orthologs and paralogs of nucleic acids that encode hairy type kinases of Group I as well as Group I hairy kinase polypeptides. A homolog can be in the form of a "substitutional variant" of a protein, i.e., wherein at least one residue in an amino acid sequence has been removed and a different residue has been inserted in its place. Amino acid substitutions are typically the individual residues, but may be grouped according to the functional limitations placed on the polypeptide; Inserts will usually be in the order of approximately 1 to 10 amino acid residues. Preferably, amino acid substitutions comprise conservative amino acid substitutions. Conservative substitution tables are readily available in the art. The table below gives examples of conserved amino acid substitutions. Table 4: Examples of conserved amino acid substitutions A homolog may also have the form of an "insertional variant" of a protein, ie, wherein one or more amino acid residues are introduced at a predetermined site of a protein. Inserts may comprise N-terminal and / or C-terminal fusions as well as intrasequence insertions of single or multiple amino acids. In general within the amino acid sequence will be smaller than N-terminal or C-terminal fusions, on the order of approximately 1 to 10 residues. Examples of N-terminal or C-terminal fusion proteins or peptides include the binding domain or the activation domain of a transcriptional activator in accordance with that used in the yeast two-hybrid system, phage coat protein, (histidine) -6, glutathione S-transferase marker, protein A, maltose binding protein, dihydrofolate reductase, TAG_100_ epitope, c-myc epitope, FLAG®-epitope, lacZ, CMP (calmodulin binding peptide) , epitope of HA, protein C epitope and VSV epitope. Homologues in the form of "deletion variants" of a protein are characterized by the removal of one or more amino acids from a protein. Amino acid variants of a protein can be easily made using synthetic peptide techniques well known in the art, such as for example solid phase peptide synthesis and the like, or by manipulations of recombinant DNA. Methods for manipulating DNA sequences to produce substitution, insertion or deletion variants of a protein are well known in the art. For example, techniques for making substitution mutations at predetermined sites on DNA are well known to those skilled in the art and include M13 mutagenesis, T7 gene mutagenesis in vitro (USB, Cleveland, OH), site-directed mutagenesis QuickChange (Stratagene, San Diego, CA), site-directed mutagenesis mediated by polymerase chain reaction and other site-directed mutagenesis protocols. Hox5 polypeptide of HDZip class I or homologue thereof; the nucleic acid encoding a nitrate transporter protein (NRT) or a homolog thereof; the nucleic acid encoding a YEP16 polypeptide; and the nucleic acid encoding a Group I hairy kinase or a homologue thereof can be a derivative. "Derivatives" include peptides, oligopeptides, polypeptides, proteins and enzymes which may comprise substitutions, deletions or additions of amino acid residues occurring naturally and not naturally compared to the amino acid sequence in a naturally occurring form of the protein. The derivatives may comprise naturally occurring, altered, glycosylated, acylated amino acid residues, prenylated or occurring not naturally compared to the amino acid sequence in a naturally occurring form of the polypeptides. A derivative may also comprise one or more non-amino acid substituents in comparison to the amino acid sequence from which, for example, a reporter molecule or another ligand, covalently or non-covalently bound to the amino acid sequence, is derived, for example a reporter molecule that is linked to facilitate its detection, and amino acid residues that do not occur naturally compared to the amino acid sequence of a naturally occurring protein. Hox5 polypeptide of HDZip class I or homologue thereof may be encoded by an alternative splice variant; the NRT polypeptide or homologue thereof may be encoded by an alternative splice variant; the YEP16 polypeptide or homologue thereof may be encoded by an alternative splice variant; and the Group I hairy kinase or a homologue thereof may be encoded by an alternative splice variant. When the sequence useful in the methods of the present invention is a nucleic acid encoding a hox5 polypeptide of HDZip class I or homologue thereof, the splice variant encodes a polypeptide comprising from the N-terminus to the C-terminus: (i) ) an acidic picture; and (ii) a Class I homeodomain; and (iii) a leucine closure with more than 5 heptates. In addition, the Hox5 polypeptide of HDZip class I or a homolog thereof may comprise one or both of the following: (a) a Trp tail; and (b) the amino acid motif RPFF, wherein R is Arg, P Pro and F Phe. Within this reason, one or more conservative changes are allowed in any position and / or one or two non-conservative changes in any position. The motif of (b) precedes the acid table, when the protein is examined from the N-terminus to the C-terminus. Splice variants of nucleic acid sequences provided in Table A are also preferred. A splice variant is especially preferred. a nucleic acid sequence as represented by SEQ ID NO: 1. When the sequence useful in the methods of the present invention is a NRT polypeptide or a homologue thereof or a nucleic acid encoding said polypeptide, the splice variant encodes a polypeptide comprising the MFS_1 domain and a transmembrane domain located C-terminally of the MFS_1 domain, and preferably also one or more conserved signature sequences of SEQ ID NO: 57 to SEQ ID NO: 64 according to that defined above. Splicing variants of any of the nucleic acids provided in Table B are also preferred. More preferably, it is a splice variant of the SEQ nucleic acid.

ID NO: 52. When the sequence useful in the methods of the present invention is a nucleic acid encoding YEP16, the splice variant is a nucleic acid sequence represented by SEQ ID NO: 127 or SEQ ID NO: 129. When the sequence useful in the methods of the present invention is a nucleic acid encoding a Group I hairy kinase or a homologue thereof, alternative splice variants are splice variants of the nucleic acid represented by any of SEQ ID NO. : 146, SEQ ID NO: 148, SEQ ID NO: 150, SEQ ID NO: 152, SEQ ID NO: 154, SEQ ID NO: 156, SEQ ID NO: 158, SEQ ID NO: 160, SEQ ID NO: 162 , SEQ ID NO: 164, SEQ ID NO: 166, SEQ ID NO: 168, SEQ ID NO: 170, SEQ ID NO: 172, SEQ ID NO: 174 and SEQ ID NO: 176. Splicing variants are also preferred. encode a polypeptide having: (i) at least 77% sequence identity with the amino acid sequence represented by SEQ ID NO: 147; and (ii) motif I: R / H / V / N / Q E / G LK G / N and motif II: K Q / N CXXX G / A / S, where X can be any amino acid. The present invention therefore offers a method for improving the growth characteristics of plants, which comprises modulating the expression in a plant of an alternative splice variant of a nucleic acid encoding a hox5 polypeptide of leucine closure. homeodomain (HDZip) class I or a homolog thereof; or comprising modulating the expression in a plant of an alternative splice variant of a nucleic acid encoding a NRT polypeptide or a homologue thereof; or comprising the modulation of the expression in a plant of an alternative splice variant of a nucleic acid encoding a YEP16 polypeptide or a homologue thereof; or comprising the modulation of the expression in a plant of an alternative splicing variant of a nucleic acid encoding a Group I glycogen synthase kinase (Group I hairy kinase) or a homologue thereof. The term "alternative splice variant" as used herein encompasses variants of a nucleic acid sequence wherein selected introns and / or exons have been cut, replaced, or aggregated, or where introns have been shortened or elongated. Such variants will be the variants in which the biological activity of the protein is conserved, which can be achieved by the selective retention of functional segments of the protein. Such splice variants can be found in nature or they can be artificial. Methods for making such splice variants are well known in the art. The homolog may also be encoded by an allelic variant of a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof; or you can be encoded by an allelic variant of a nucleic acid encoding a nitrate transporter protein (NRT) or a homolog thereof; or encoded by an allelic variant of a nucleic acid encoding a YEP16 polypeptide; or encoded by an allelic variant of a nucleic acid encoding a Group I hairy kinase, or a homologue thereof. When the sequence useful in the methods of the present invention is a nucleic acid encoding a hox5 polypeptide of HDZip class I or a homologue thereof, the allelic variant encodes a polypeptide comprising from the N terminus to the C terminus: (i) ) an acidic picture; and (ii) a class I homeodomain; and (iii) a leucine closure with more than 5 heptates. In addition, the Hox5 polypeptide of HDZip class I or a homolog thereof may comprise one or both of the following: (a) a Trp tail; and (b) the amino acid motif RPFF, wherein R is Arg, P is Pro and F is Phe. Within this reason, one or more conservative changes are allowed in any position, and / or one or two non-conservative changes in any position. The reason for (b) precedes the acid table, when the protein is examined from the N-terminus to the C-terminus. Allelic variants of nucleic acid sequences are also preferred in Table A. Most preferably it is an allelic variant of a nucleic acid sequence according to that represented by SEQ ID NO: 1. When the sequence useful in the methods of the present invention is a NRT polypeptide or homologue thereof or a nucleic acid encoding them, the allelic variant encodes a polypeptide comprising the MFS_1 domain and a transmembrane domain located C -terminally of the domain MFS_1, and preferably also one or more of the sequences of conserved signatures of SEQ ID NO: 57 to SEQ ID NO: 64 in accordance with what is defined above. Allelic variants of any of the nucleic acids provided in Table I are also preferred. Especially preferred is an allelic variant of the nucleic acid of SEQ ID NO: 52. When the sequence useful in the methods of the present invention is a nucleic acid encoding YEP16, the allelic variant is of a nucleic acid sequence represented by SEQ ID NO: 127 or SEQ ID NO: 129. When the sequence useful in the methods of the present invention is a nucleic acid encoding a Group hairy-like kinase. I or its homologue, the allelic variants are allelic variants of the nucleic acid represented by any of SEQ ID NO: 146, SEQ ID NO: 148, SEQ ID NO: 150, SEQ ID NO: 152, SEQ ID NO: 154, SEQ ID NO: 156, SEQ ID NO: 158, SEQ ID NO: 160, SEQ ID NO: 162, SEQ ID NO: 164, SEQ ID NO: 166, SEQ ID NO: 168, SEQ ID NO: 170, SEQ ID NO: 172, SEQ ID NO: 174 and SEQ ID NO: 176. Preferred additionally the allelic variants that encode a polypeptide having: (i) a sequence identity of at least 77% with the amino acid sequence represented by SEQ ID NO: 147; and (ii) motif I: R / H / V / N / Q E / G LK G / N and motif II: K Q / N CXXX G / A / S, where X can be any amino acid. The present invention therefore offers a method for improving the growth characteristics of plants, comprising the modulation of the expression in a plant of an allelic variant of a nucleic acid encoding a class I homeodomain leucine closure polypeptide hox5. (HDZip) or a homolog thereof; or comprising modulating the expression in a plant of an allelic variant of a nucleic acid encoding a NRT polypeptide or a homologue thereof; or comprising the modulation of the expression in a plant of an allelic variant of a nucleic acid encoding a YEP16 polypeptide or a homologue thereof; or comprising the modulation of the expression in a plant of an allelic variant of a nucleic acid encoding a Group I glycogen synthase kinase (Group I hairy kinase) or a homologue thereof. Allelic variants exist in nature and the use of these natural alleles is contemplated within the methods of the present invention. Allelic variants encompass Polymorphisms of Individual Nucleotides (SNPs), as well as Polymorphisms of Small Insertion / Deletion (INDELs). The size of INDELs is usually less than 100 base pairs. SNPs and INDELs form the largest group of sequence variants in natural polymorphic strains of most organisms. According to the present invention, the modulated expression of the nucleic acid or variant thereof is contemplated. Methods for modulating the expression of genes or gene products are well documented in the art and include, for example, overexpression driven by appropriate promoters, the use of transcription enhancers or translational enhancers. Isolated nucleic acids serving as promoters or enhancer elements can be introduced in an appropriate position (typically upstream) of a non-heterologous form of a polynucleotide to up-regulate the expression of the nucleic acid or variant thereof. For example, endogenous promoters can be altered in vivo by mutation, deletion and / or substitution (see, Kmiec, U.S. Patent No. 5,565,350; Zarling et al, PCT / US93 / 03868), or isolated promoters can be introduced into a cell. vegetable in the proper orientation and at the correct distance of a gene of the present invention for the purpose of controlling the expression of the gene. Methods to reduce the expression of genes or gene products with well documented in the art. If the expression of a polypeptide is desired, it is generally It is desirable to include a polyadenylation region at the 3 'end of the polynucleotide coding region. The polyadenylation region can be derived from the natural gene, from a variety of other plant genes, or from T-DNA. The 3 'end sequence to be added can be derived, for example, from genes of nopaline synthase or octopine synthase, or alternatively from another plant gene, or from another eukaryotic gene. An intron sequence can also be added to the 5 'untranslated region or to the coding sequence of the partial coding sequence to increase the amount of mature message that accumulates in the cytosol. The inclusion of intron that can be spliced into the transcription unit in plant and animal expression constructs increases gene expression both at the mRNA level and at the protein level up to 1000 times (Buchman and Berg (1988) Mol. Cell biol. 4395-4405; Callis et al. (1987) Genes Dev 1: 1183-1200). Such intron increase of gene expression is typically greater when placed near the 5 'end of the transcription unit. The use of corn introns Adhl - S intron 1, 2, and 6, the Bronze-1 intron are known in the art. See, in general terms, The Maize Handbook, Chapter 1 16, Freeling and Walbot, Eds., Springer, N.Y. (1994). The invention also offers genetic constructs and vectors to facilitate the introduction and / or expression of the nucleotide sequences useful in the methods according to the present invention. Accordingly, a gene construct is provided comprising: (i) a hox5 nucleic acid of HDZip class I or variant thereof; or a nucleic acid encoding NRT or variant thereof; or a nucleic acid encoding YEP16 or variant thereof; or a nucleic acid encoding Group I hairy kinase or variant thereof; (ii) one or more control sequences capable of driving the expression of the nucleic acid sequence of (i); and optionally (iii) a transcription termination sequence. The constructs useful in the methods according to the present invention can be constructed using recombinant DNA technology well known to those skilled in the art. The gene constructs can be inserted into vectors, which can be commercially available, suitable for transformation into plants and suitable for expression of the gene of interest in the transformed cells. The invention therefore offers the use of a gene construct in accordance with that defined above in the methods of the invention.

Plants are transformed with a vector comprising the sequence of interest. The sequence of interest is operatively linked to one or more control sequences (at least one promoter). The term "regulatory element", "control sequence" and "promoter" are all used interchangeably herein and should be considered in a broad context to refer to regulatory nucleic acid sequences capable of effecting the expression of the sequences to which they are subject. linked Within the framework of the terms mentioned above are transcriptional regulatory sequences derived from a classical eukaryotic genomic gene (including the TATA box that is required for the initiation of accurate transcription, with or without a CCAAT box sequence) and additional regulatory elements (ie say, upstream activation sequences, enhancers and silencers) that alter gene expression in response to developmental and / or external stimuli, or specifically for tissue. A regulatory sequence for the transcription of a classical prokaryotic gene is also included within the term, in which case it may include a -35 box sequence and / or box-10 transcriptional regulatory sequences. The term "regulatory element" also encompasses a synthetic fusion molecule or derivative that confers, activates or enhances the expression of a nucleic acid molecule in a cell, tissue or organ. He The term "operably linked" as used herein refers to a functional link between the promoter sequence and the gene of interest, such that the promoter sequence can initiate transcription of the gene of interest. Advantageously, any type of promoter can be used to boost the expression of the nucleic acid sequence. The promoter may be an inducible promoter, i.e. having an initiation of transcription induced or increased in response to a developmental, chemical, environmental or physical stimulus. An example of an inducible promoter is an inducible promoter, that is, an activated promoter when a plant is exposed to various stress conditions. In addition or alternatively, the promoter may be a preferred tissue promoter, i.e., a promoter capable of preferentially initiating transcription in certain tissues, such as leaves, roots, seed tissue, etc. Promoters capable of initiating transcription in certain tissues are only known herein as "tissue-specific". Preferably, the hox5 nucleic acid of HDZip class I or variant thereof; the nucleic acid encoding NRT or variant thereof; the nucleic acid encoding Group I hairy kinase or variant thereof is operably linked to a constitutive promoter. A promoter constitutive is transcriptionally active during most phases of growth and development but not necessarily in all phases of growth and development and is expressed in a substantially ubiquitous manner. The constitutive promoter is preferably a GOS2 promoter, more preferably the constitutive promoter is a rice GOS2 promoter, preferably additionally the constitutive promoter is represented by a nucleic acid sequence substantially similar to SEQ ID NO: 33 or SEQ ID NO: 178 , more preferably the constitutive promoter is in accordance with that represented by SEQ ID NO: 33 or SEQ ID NO: 178. It should be clear that the application of the present invention is not restricted to the HDxip class I or variant hox5 nucleic acid. of the same; the nucleic acid encoding NRT or variant thereof; or the nucleic acid encoding Group I hairy kinase or variant thereof when driven by a GOS2 promoter. Examples of other constitutive promoters that can also be used to effect the methods of the present invention are shown in Table 5 below. Table 5: Examples of constitutive promoters Preferably, the nucleic acid sequence encoding a YEP16 polypeptide or a homologue thereof is operably linked to a seed-specific promoter. A specific promoter for seeds is a promoter that is transcriptionally active predominantly in seed tissue. A specific seed promoter may also have some residual activity elsewhere. Preferably, the seed specific promoter is a specific promoter for endosperm and / or a promoter specific for aleurone, which means that the promoter is transcriptionally active predominantly in endosperm tissue and / or in the aleurone layers of a seed, even when a certain residual activity or expression of leak can be observed in other parts. Preferably, the promoter is an oleosin promoter, such as rice (SEQ ID NO: 143). It should be clear that the applicability of the present invention is not limited to a nucleic acid encoding YEP16 represented by SEQ ID NO: 127 or SEQ ID NO: 129, nor is the application of the present invention limited to the expression of a nucleic acid which encodes YEP16 when driven by an oleosin promoter. Examples of other seed-specific promoters that can also be used to boost expression of a nucleic acid encoding a YEP16 polypeptide or homologue thereof are shown in Table 6 below. Table 6: Examples of specific promoters for seed Gene Source Reference Reference Pattern For the identification of functionally equivalent promoters, the strength of the promoter and / or the expression pattern of a candidate promoter can be analyzed, for example, by operatively linking the promoter with a reporter gene and assaying the level of expression and standard. of the reporter gene in various tissues of the plant.

Suitable well-known reporter genes include, for example, beta-glucuronidase or beta-galactosidase. The promoter activity is assayed by measuring the enzymatic activity of beta-glucuronidase or beta-galactosidase. The strength of the promoter and / or expression pattern can then be compared with those of a reference promoter (as for example used in the methods of the present invention). Alternatively, the strength of the promoter can be assayed by quantifying mRNA levels or by comparing mRNA levels with nucleic acid used in the methods of the present invention, with mRNA levels of domestic genes such as 18S rRNA, using methods known in the art, such as for example the Northern blot method with autoradiogram densitometric analysis, quantitative real-time polymerase chain reaction or RT-PCR (Heid et al., 1996 Genome Methods 6: 986-994). In general, by "weak promoter" is meant a promoter that drives the expression of a coding sequence at a low level. By "low level" is meant levels of approximately 1 / 10,000 transcripts to approximately 1 / 100,000 transcripts, to approximately 1 / 500,0000 transcripts per cell. Conversely, a "strong promoter" drives the expression of a coding sequence at a high level, or at about 1/10 transcripts to about 1/100 transcripts up to approximately 1 / 1,000 transcripts per cell. Optionally, one or more terminator sequences can also be used in the construct introduced in the plant. A "terminator" encompasses a control sequence that is a DNA sequence at the end of a transcriptional unit that signals 3 'processing and polyadenylation of a primary transcript and transcription termination. Additional regulatory elements may include transcriptional enhancers as well as translation. Those skilled in the art will be aware of terminator and enhancer sequences that may be suitable for use in the realization of the present invention. Such sequences will be known or can easily be obtained by a person skilled in the art. The genetic constructs of the present invention may further include an origin of replication sequence that is required for maintenance and / or replication in a specific cell type. An example is when a genetic construct must be maintained in a bacterial cell as an episomal genetic element (e.g., plasmid or cosmid molecule). Preferred replication origins include, without limitation to these examples, fl-ori and colEl. The genetic construct may optionally comprise a selectable marker gene. As used herein, the term "selectable marker gene" includes any gene that provides a phenotype in a cell where it is expressed in order to facilitate the identification and / or selection of cells that are transfected or transformed with a nucleic acid construct of the invention. For the detection of the successful transfer of the nucleic acid sequences as used in the methods of the present invention and / or selection of transgenic plants comprising these nucleic acids, it is advantageous to use marker genes (or reporter genes). Accordingly, the genetic construct may optionally comprise a selectable marker gene. As used herein, the term "selectable marker", "selectable marker gene" or "reporter gene" includes any gene that provides a phenotype in a cell where it is expressed to facilitate the identification and / or selection of cells that are transfected or transformed with a nucleic acid construct of the invention. These marker genes allow the identification of a successful transfer of the nucleic acid molecules through a series of different principles. Suitable markers can be selected from markers that provide resistance to antibiotics or herbicides, that introduce a new metabolic trait or that allow visual selection. Examples of selectable marker genes include genes that provide resistance to antibiotics (as per example nptll that phosphorylates neomycin and kanamycin, or hpt, which phosphorylates hygromycin, or genes that provide resistance, for example, bleomycin, streptomycin, tetracycline, chloramphenicol, ampicillin, gentamicin, geneticin (G418), spectinomycin or blasticidin), herbicides (eg bar that provides resistance to Basta, aroA or gox that provides resistance against glyphosate, or genes that provide resistance such as for example to imidazolinone, phosphinothricin or sulfonylurea), or genes that provide a metabolic trait (such as manA) that allows plants to use mannose as the sole source of carbon or xylose isomerase for the use of xylose, or anti-nutritive markers such as resistance to 2-deoxyglucose). Expression of visual marker genes results in color formation (eg, β-glucuronidase, GUS or β-galactosidase with their colored substrates, eg X-Gal), luminescence (such as luciferin / luciferase system) or fluorescence (green fluorescent protein, GFP, and derivatives thereof). This list represents only a small number of possible markers. People with knowledge of the subject will be familiar with such markers. Different markers are preferred, depending on the organism and the selection method. It is known that when a stable integration or Transient nucleic acids in plant cells, only a minority of cells absorb foreign DNA and, if desired, integrate it into their genome, depending on the expression reader used and the transfection technique used. To identify and select these integrants, a qen encoding a selectable marker (such as those described above) is usually introduced into the host cells in conjunction with the gene of interest. These labels can be used, for example, in mutants in which these genes are not functional, for example, by deletion by conventional methods. In addition, the nucleic acid molecules encoding a selectable marker can be introduced into a host cell in the same vector comprising the sequence and encoding the polypeptides of the invention or used in the methods of the invention, or in a separate vector. Cells that have been stably transfected with the introduced nucleic acid can be identified for example by selection (for example, cells that integrated the selectable marker survive while the other cells die). Since marker genes, especially genes for resistance to antibiotics and herbicides, are no longer desired or are not required in the transgenic host cells once the nucleic acids have been successfully introduced, the process according to the present invention for introducing nucleic acids usefully employs techniques that allow the removal or excision of these marker genes. One method of this type is the method known as co-transformation. The co-transformation method employs two vectors simultaneously for transformation, one vector carrying the nucleic acid according to the present invention and a second vector carrying the marker gene (s). A large proportion of the transformants receives, or in the case of plants, comprises (up to 40% or more of the transformants) both vectors. In case of transformation with Agrobacteria, the transformants usually receive only a part of the vector, that is, the sequence flanked by the T-DAN, which usually represents the expression cassette. The marker genes can be subsequently cut from the transformed plant by making crosses. In other methods, marker genes integrated into a transposon are used for transformation in conjunction with the desired nucleic acid (known as Ac / Ds technology). The transformants can be crossed with a transposase source or the transformants are transformed with a nucleic acid construct that confers expression of a transposase, transiently or stably. In some cases, approximately 10%, the transposon jumps out of the genome of the host cell once the transformation has been effected successfully and lost. In a further number of cases, the transposon jumps to a different location, in these cases, the marker gene must be eliminated by making crosses. In microbiology, techniques were developed that make possible or facilitate the detection of such events. An additional helpful method is based on what is known as recombination systems. Whose advantage is that cross-elimination can be avoided. The best known system of this type is what is known as the Cre / lox system. I thought it is a recombinase that removes the sequences located between the loxP sequences. If a marker gene is integrated between the loxP sequences, it is removed once the transformation has been carried out successfully, by expression of the recombinase. Additional recombination systems are the HIN / HIX, FLP / FRT and REP / STB systems (Tribble et al., J. Biol. Chem., 275, 2000: 22255-22267; Vel urugan et al., J. Cell Biol. , 149, 2000: 553-566). A site-specific integration into the plant genome of the nucleic acid sequences according to the present invention is possible. Naturally, these methods can be applied to microorganisms such as yeast, fungi or bacteria. In a preferred embodiment, a gene construct is provided comprising: (i) a hox5 nucleic acid of HDZip class I or variant thereof; or a nucleic acid encoding NRT or variant thereof; or a nucleic acid encoding Group I hairy kinase or variant thereof; (ii) a constitutive promoter capable of driving the expression of the nucleic acid sequence of (i); and optionally (iii) A transcription termination sequence. The constitutive promoter is preferably a GOS2 promoter, more preferably the constitutive promoter is the rice GOS2 promoter, further preferably the constitutive promoter is represented by a nucleic acid sequence substantially similar to SEQ ID NO: 33 or SEQ ID NO: 178 , more preferably the constitutive promoter is in accordance with that represented by SEQ ID NO: 33 or SEQ ID NO: 178. The invention further provides the use of a construct in accordance with that defined above in the methods of the present invention. In another preferred embodiment, a gene construct is provided comprising: (i) a nucleic acid encoding YEP16 or variant thereof; (ii) a seed-specific promoter capable of driving the expression of the nucleic acid sequence of (i); and optionally (iii) a transcription termination sequence. The present invention also encompasses plants that can be obtained through the methods according to the present invention. The present invention therefore offers plants, plant parts (including plant cells) that can be obtained through the methods of the present invention, said plants or parts of plants (including cells) comprise a hox5 nucleic acid of HDZip class I of transgen or variant thereof; a nucleic acid encoding transgene NRT or variant thereof; a nucleic acid encoding transgene YEP16 or variant thereof; or a nucleic acid encoding Group I hairy kinase transgene or variant thereof. The invention also provides a method for the production of transgenic plants having improved growth characteristics, particularly a higher yield, compared to corresponding wild-type plants or other control plants, which comprises the introduction and expression of a plant of either the nucleic acids described herein as useful in the methods of the invention.

For the purposes of the present invention, the terms "transgenic", "transgene" or "recombinant" refer to, for example, a nucleic acid sequence, an expression cassette, a gene construct or a vector comprising the sequence of nucleic acid or an organism transformed with the nucleic acid sequences, expression cassettes or vectors according to the present invention, all these constructions obtained through recombinant methods in which: a) the nucleic acid sequences encoding proteins useful in the methods of the present invention invention, or b) the genetic control sequence (s) that are (are) operably linked to the nucleic acid sequence according to the present invention such as for example a promoter, c) a) and b) no they are located in their natural genetic environment or have been modified by recombinant methods, it being possible for the modification to assume the form, for example, of a substitution, addition, deletion, inversion, or insertion of one or more nucleotide residues. The natural genetic environment is understood as referring to the genomic or chromosomal locus in the original plant or the presence in a genomic library. In the case of a genomic library, the natural genetic environment of the nucleic acid sequence is preferably conserved, at least partially. The environment flanks the nucleic acid sequence on at least one side and has a sequence length of at least 50 base pairs, preferably at least 500 base pairs, particularly preferably at least 1,000. base pairs, and most especially at least 5,000 base pairs. A naturally occurring expression cassette-for example, the naturally occurring combination of the natural promoter of the nucleic acid sequences with the corresponding nucleic acid sequence encoding a polypeptide useful in the methods of the present invention, as defined above. - it becomes a cassette of transgenic expression when its expression cassette is modified by synthetic (artificial), non-natural methods, for example, mutagenic treatment. Suitable methods are described, for example, in US 5,565,350 or WO 00/15815. More specifically, the present invention offers a method for the production of transgenic plants having improved growth characteristics (particularly improved yield), said method comprising: (i) introduction and expression in a plant, plant part or plant cell of a hox5 nucleic acid of HDZip class I or variant thereof; a nucleic acid encoding NRT or variant thereof; a nucleic acid encoding YEP16 or variant thereof; a nucleic acid encoding Group I hairy kinase or variant thereof; (ii) cultivate the plant cell under conditions that promote the growth of the plant and its development.

The nucleic acid can be introduced directly into a plant cell or into the plant itself (including the introduction of a tissue, organ, or any other part of the plant). In accordance with a preferred feature of the present invention, the nucleic acid is preferably introduced into a plant by transformation. The term "transformation" as used herein encompasses the transfer of an exogenous nucleotide into a host cell, regardless of the method used for the transfer. A plant tissue capable of subsequent clonal propagation, either by organogenesis or embryogenesis, can be transformed with a genetic construct of the present invention and a whole plant can be regenerated therefrom. The particular tissue selected will vary according to the clonal propagation systems available for the particular transformed species and more suitable to said species. Exemplary tissue blanks include leaf discs, pollen, embryos, cotyledons, hypocotyls, megagametophytes, callus tissue, existing meristematic tissue (e.g., apical meristem, axillary buds, and root meristems), induced meristem tissue (e.g. , cotyledon meristem and hypocotyl meristem). The polynucleotide can be introduced transiently or stably into a host cell and can be maintained in a non-integrated manner, for example, in the form of a plasmid. Alternatively, you can integrate into the host's genome. The resulting transformed plant cell can then be used to regenerate a transformed plant in a known manner by persons skilled in the art. The transformation of plant species is currently a relatively routine technique. Advantageously, any of several transformation methods for the gene of interest in a suitable ancestor cell can be employed. Transformation methods include the use of liposomes, electroporation, chemical substances that increase the absorption of free DNA, injection of DNA directly into the plant, particle bombardment, transformation using viruses or pollen and microprojection. Methods can be selected from the calcium / polyethylene glycol method for protoplasts ((Krens, FA et al. (1982) Nature 296, 72-74; Negrutiu I et al. (1987) Plant Mol Biol 8: 363-373); protoplasts (Shillito RD et al. (1985) Bio / Technol 3, 1099-1102), microinjection in plant material (Crossway A et al. (1986) Mol Gen Genet 202: 179-185), bombardment of roofing particles with RNA or DNA (Klein TM et al (1987) Nature 327: 70), virus infection (non-integrative) and the like Transgenic rice plants are preferably produced through Agrobacterium-mediated transformation using any of the well known methods for the transformation of rice as described in any of the following: Published European Patent Application EP 1198985 Al, Aldemita and Hodges (Planta 199: 612-617, 1996); Chan et al. (Plant Mol Biol 22 (3): 491-506, 1993), Hiei el al. (Plant J 6 (2): 271-282, 1994), whose disclosures are incorporated by reference herein as if they were fully reproduced. In the case of the corn transformation, the preferred method is according to what is described in Ishida et al. (Nat. Biotechnol 14 (6): 745-50, 1996) or Frame et al. (Plant Physiol 129 (1): 13-22, 2002), the disclosures of which are incorporated herein by reference as if they were fully reproduced. Generally after a transformation, plant cells or groups of plant cells are selected to determine the presence of one or several markers encoded by genes that can be expressed in plant cotransferred with the gene of interest, after which the transformed material is regenerated into a whole plant. After DNA transfer and regeneration, putatively transformed plants can be evaluated, for example using Southern analysis, to determine the presence of the gene of interest, number of copies and / or genomic organization. Alternatively or additionally, the levels of newly introduced DNA expression can be monitored using Northern and / or Western analysis, or quantitative polymerase chain reaction, all of which are techniques are well known to those of ordinary skill in the art. The transformed transformed plants can be propagated through various means, such as by clonal propagation or classical breeding techniques. For example, a first generation (or Ti) transformed plant can be reproduced inbreeding to provide homozygous second generation (or T2) transformants, and T2 plants can be propagated further through classical breeding techniques. The transformed organisms generated can take various forms. For example, they can be chimeras of transformed cells and non-transformed cells; clonal transformants (e.g., all cells transformed to contain the expression cassette); grafts of transformed and non-transformed tissues (for example, in plants, a transformed rhizome grafted onto a non-transformed offspring). The present invention clearly extends any plant cell or plant produced through any of the methods described herein, and all parts of plants and propagules thereof. The present invention also encompasses the progeny of a primary transformed or transfected primary cell, tissue, organ or plant that has been produced at through any of the methods mentioned above, the only requirement being that the progeny present the same (s) characteristic (s) genotypic (s) and / or phenotypic (s) that the characteristics produced by the ancestor in the methods in accordance with the present invention. The invention also includes host cells comprising a hox5 nucleic acid of HDZip class I isolated or variant thereof; host cells comprising a nucleic acid encoding isolated NRT or variant thereof; host cells comprising a nucleic acid encoding isolated YEP16 or variant thereof; host cells comprising a nucleic acid encoding Group I hairless kinase or variant thereof. Preferred host cells are plant cells. The invention also encompasses harvestable parts of a plant such as, but not limited to, these examples, seeds, leaves, fruits, flowers, stems, rhizoses, tubers and bulbs. The invention also relates to products derived from a harvestable part of a plant of this type, such as for example dry granules or powder, oil, fat and fatty acids, starch or proteins. The present invention also encompasses the use of hox5 nucleic acids of HDZip class I and variants thereof and the use of hox5 HDZip class I polypeptides and homologs thereof; the use of nucleic acids that encode NRT and variants thereof and the use of NRT polypeptides and homologs thereof; the use of nucleic acids encoding YEP16 and variants thereof and the use of YEP16 polypeptides and homologs thereof; the use of nucleic acids encoding Group I hairy kinase and variants thereof and the use of Group I hairy kinase polypeptides and homologs thereof. Such uses refer to the improvement of any of the characteristics of plant growth in accordance with what is defined above. Hox5 nucleic acids of HDZip class I or variant thereof, or HDZip class I polypeptides or homologs thereof; nucleic acids encoding NRT and variants thereof, or NRT polypeptides and homologs thereof; nuclei encoding YEP16 and variants thereof or YEP16 polypeptides and homologs thereof; nucleic acids encoding Group I hairy kinase and variants thereof, or Group I hairy-like kinase polypeptides and homologs thereof may be used in breeding programs where a DNA marker is identified that may be genetically linked to one of the nucleic acids or 'variants mentioned above. The nucleic acids or variants, or polypeptides or homologs thereof can be used to define a molecular marker. This DNA or protein marker can then be used in breeding programs to select plants that have improved growth characteristics (such as increased yield). The nucleic acids or variants are in accordance with what is defined above. Allelic variants of a nucleic acid / hox5 gene of HDZip class I; a nucleic acid / gene encoding NRT; a nucleic acid / gene encoding YEP16; a nucleic acid / gene encoding Group I hairy kinase can also be used in marker-assisted breeding programs. Such breeding programs sometimes require the introduction of allelic variation by mutagenic treatment of the plants, the use for example of EMS mutagenesis; alternatively, the program may start with a collection of allelic variants of what is known as a "natural" origin unintentionally caused. The identification of allelic variants is then effected, for example, by polymerase chain reaction. This is followed by a step of selecting higher allelic variants of the sequence in question that provide improved growth characteristics, such as higher throughput. The selection is typically carried out by monitoring the growth performance of plants containing allelic variants different from the sequence in question, for example, different allelic variants of any of the nucleic acids / genes described herein as useful in the methods of the present invention. Growth performance can be monitored in a greenhouse or field. Additional optional steps include the crossing of the plants in which the top allelic variant was identified with another plant. This can be used, for example, to make a combination of interesting genotype characteristics. The nucleic acid and variants mentioned above can also be used as probes to genetically and physically map the genes of which they are a part, and as markers for traits related to these genes. This information can be useful in the improvement of plants in order to develop lines with desired genotypes. Said use of the nucleic acids or variants requires only a nucleic acid sequence of at least 156 nucleotides in length. The nucleic acids or variants can be used as restriction fragment length polymorphism (RFLP) markers. Southern blots (Sambrook J, Fritsch EF and Maniatis T (1989) Molecular Cloning, A Laboratory Manual) of genomic DNA from plants digested with restriction enzymes can be probed with the nucleic acids or variants. The resulting band patterns can then be subjected to genetic analysis using computer programs such as MapMaker (Lander et al. al (1987) Genomics 1: 174-181) in order to build a genetic map. In addition, nucleic acids can be used to probe Southern blots containing genomic DNAs treated with restriction endonuclease from a set of individuals representing ancestor and progeny of a defined genetic cross. The segregation of DNA polymorphisms is noted and used to calculate the position of the nucleic acid or variant in the genetic map previously obtained using this population (Botstein et al. (1980) Am. J. Hum. Genet. 32: 314- 331). The production and use of probes derived from plant genes for use in genetic mapping is described in Bematzky and Tanksley (1986) Plant Mol. Biol. Repórter 4: 37-41. Numerous publications describe the genetic mapping of specific cDNA clones using the methodology presented above or variations thereof. For example, interbreeding F2 populations, backcross populations, randomly crossed populations, almost isogenic lines, and other groups of individuals can be used for mapping. Such methodologies are well known by people with knowledge in the field. Nucleic acid probes can also be used for physical mapping (ie, placement of sequences on physical maps, see Hoheisel et al., In: Non-mammalian Genomic Analysis: A Practical Guide, Academic Press 1996, pp. 319-346, and references cited there). In another embodiment, the nucleic acid probes can be used in direct fluorescence in hybridization (FISH) mapping (Trask (1991) Trends Genet 7: 149-154). Although current methods of FISH mapping favor the use of large clones (from several kb to several hundred kb, see Laan et al. (1995) Genome Res. 5: 13-20), improvements in sensitivity may allow performance of FISH mapping using shorter probes. Several methods based on nucleic acid amplification for genetic and physical mapping can be performed using nucleic acids. Examples include allele-specific amplification (Kazazian (1989) J. Lab. Clin. Med 11: 95-96), fragment polymorphisms amplified by polymerase chain reaction (CAPS, Sheffield et al. (1993) Genomics 16: 325- 332), specific linkage for allele (Landegren et al. (1988) Science 241: 1077-1080), nucleotide extension reactions (Sokolov (1990) Nucleic Acid Res. 18: 3671), hybrid mapping by radiation (Walter et al. al. (1997) Nat. Genet 7: 22-28) and Happy Mapping (Dear and Cook (1989) Nucleic Acid Res. 17: 6795-6807). For these methods, the sequence of a nucleic acid is used to design and produce primer pairs for use in the amplification reaction or in primer extension reactions. The design of such primers is well known to people with knowledge in the subject. In methods employing genetic mapping based on polymerase chain reaction, it may be necessary to identify differences in DNA sequences between the ancestors and the cross-mapping in the region corresponding to the nucleic acid sequence of the present invention. However, this is generally unnecessary for mapping methods. The methods according to the present invention result in plants having improved growth characteristics, in accordance with what is described above. These improved growth characteristics can also be combined with other economically beneficial traits in order to further improve these traits that improve yield, tolerance to other abiotic and biotic stresses, traits that modify various architectural features and / or biochemical characteristics and / or physiological DESCRIPTION OF THE FIGURES The present invention will be described below with reference to the following figures in which: Figure 1 shows a multiple alignment of HDZip class I homeodominies from different plant sources, using the AlignX VNTI multiple alignment program, based on a modified ClustalW algorithm (InforMax, Bethesda, MD, http://www.informaxinc.com), with adjustments for omission for space opening penalty of 10 and a space extension of 0.05. The invariant amino acids of Lie, W48, F4g, N51 and R53 homeodomain are vertically framed. Preferred amino acids A46 and W56 of HDZip class I are also presented in vertical frames. The three helices necessary for DNA binding are marked as black squares above the alignment. The six heptad are separated by a vertical line. The seventh position within each heptad is indicated as a, b, c, d, e, f and g. Leu occupies the "d" position within each heptad, and is in a vertical box. Figure 2 shows a multiple alignment of several hox5 HDZip class I polypeptides from several plants, using the AlignX VNTI multiple alignment program, based on a modified ClustalW algorithm (InforMax, Bethesda, MD, http: // www. . com), with default settings for space opening penalty of 10 and an extension of 0.05. The three main characterized domains, from the N-terminus to the C-terminus, are in strong frames and identified as the acidic picture, the class I homeodomain, and the leucine closure of six heptad. In addition, the Trp tail and the RPFF amino acid motif are in light boxes. Figure 3 shows a binary vector for expression in Oryza sa tiva of a hox5 of HDZip class I of Oryza sa tiva under the control of a G0S2 promoter. Figure 4 presents examples of hox5 homeodomain leukin lock (HDZip) class I sequences useful for carrying out the methods in accordance with the present invention. Several sequences result from public EST assemblies (see Table A), with lower quality sequencing. As a result, fewer substitutions of nucleic acid can be expected. The start codons (ATG) and termination delimit the nucleic acid sequences. Figure 5 shows the typical domain structure of an NRT protein useful in the methods of the present invention, which is exemplified herein with SEQ ID NO: 53. The protein of SEQ ID NO: 53 comprises an MFS_1 domain starting at S69 and ends with F432, indicated in bold. C-terminally of this domain MFS_1, a putative transmembrane domain is found (T441 to P463, underlined). Figure 6 (a) shows a phylogenetic tree, where SEQ ID NO: 126 represents the protein sequence of NRT1 of rice, comprising a PTR2 domain, and figure 6 (b) a multiple alignment of the sequences listed in the Table I of Example 14. The asterisks in the multiple alignment identify amino acids that are identical between the aligned sequences, the semicolons indicate conservative substitutions and the dots represent less conserved substitutions. Figure 7 shows the binary vector for expression increased in Oryza sa tiva of a nucleic acid encoding a NRT protein of rice under the control of a G0S2 promoter. Figure 8 presents examples of useful NRT sequences (with the exception of SEQ ID NO: 125 and SEQ ID NO: 126) to carry out the methods of compliance with the present invention. The sequences SEQ ID NO: 123 and 124 are probably not full-length sequences. Figure 9 shows a binary vector for the expression in Oryza saliva of a nucleic acid encoding YEP16 of Arabidopsis thaliana YEP16 under the control of an oleosin promoter. Figure 10 shows YEP16 sequences useful in the methods of the invention. Figure 11 taken from Plant (2003) 218: 1-14 (Wang et al.), Shows the response of plants to abiotic stress. Primary stresses, such as drought, salinity, cold, heat and chemical contamination are often interconnected and cause cell damage and secondary stress, such as osmotic stress and oxidative stress. Initial stress signals (eg osmotic and ionic effects, or temperature, changes in membrane fluidity) activate the downstream signaling process and transcription controls that activate a stress response mechanism to re-establish homeostasis and protect and repair damaged proteins and membranes. An inadequate response in one or several stages in gene signaling and activation may ultimately result in irreversible changes in cellular hemeostasis and in the destruction of functional and structural proteins and membranes, leading to cell death. Figure 12, taken from TRENDS in plant Science Vol. 7, No. 10, Oct. 2002 (Claudia Jonak and Heribert Hirt) shows possible trajectories of hairy type kinase in plants. AtGSKl is a positive regulator of high saline response. WIG (GSK induced by wound) participates in the signaling of wounds. AtSKll and AtSK12 participate in a correct pattern of the flowers. Genetic and biomedical analyzes indicate that signaling of brassinosteroids (BR) mediated by BIN2 (insensitive to brassinosteroid 1), which controls the nuclear accumulation of BES1 (suppressor of BR11-EMS 1) and BRZ1 (resistant to brasinazol 1). Figure 13, taken from TRENDS in plant Science Vol. 7, No. 10, Oct. 2002 (Claudia Jonak and Heribert Hirt) shows: (a) Phylogenetic analysis of the ten glycogen synthase kinase 3 / hairy-like protein kinase (GSKs) of Arabidopsis. The GSKs of Arabidopsis can be classified into four subgroups, (b) phylogenetic tree of full-length GSK cDNAs from different plant species obtained from several BLAST searches. Brassica napus, BSKT (Y12674); Medicago sa tiva, MSK1 (X6841 1), MSK2 (X68410), MSK3 (X68409), MSK4 (AF432225), WIG (AJ295939); Nicotiana tabacum, NSK6 (Y08607), NSK59 (AJ002315), NSK91 (AJ224163), NSK111 (AJ002314), NTK-1 (X77763); Oryza sa tiva, OSK? (AB59612), OSK? (Y13437); Petunia hybrida, PSK4 (X83619), PSK6 (AJ224164), PSK7 (AJ224165), SPK6 (X83620). Alignments were made with Clustal X by the neighbor binding method using Arabidopsis MPK1 (Q39021) as an external group; trees were designed by the TreeView program. Figure 14 shows a multiple CLUSTAL alignment of hairy-type kinases of plant group I. Motives I and II are framed. Figure 15 shows a binary vector for Oryza expression of a Group I hairy kinase from Oryza sativa under the control of a GOS2 promoter.

Figure 16 presents examples of Group I hairy kinase sequences useful in carrying out the methods according to the present invention. EXAMPLES The present invention will now be described with reference to the following examples, which are presented for illustrative purposes only and are not intended to fully define or otherwise limit the scope of the invention. Unless otherwise indicated, DNA techniques recombinant were performed in accordance with standard protocols described in (Sambrook (2001) Molecular Cloning: a laboratory manual, 3rd Edition Cold Spring Harbor Laboratory Press, CSH, New York) or volumes 1 and 2 of Ausubel et al. (1994), Current Protocols in Molecular Biology, Current Protocols. Standard materials and methods for molecular work in plants are described in Plant Molecular Biology Labfase (1993) by R.D.D. Croy, published by BIOS Scientific Publications Ltd (United Kingdom) and Blackwell Scientific Publications (United Kingdom). EXAMPLES: Hox5 HDZip class I polypeptides and coding sequences Example 1: Identification of sequences related to SEQ ID NO: 1 and SEQ ID NO: 2 Sequences (full-length cDNA, ESTs or genomics) were identified among those maintained in the Entrez Nucleotides database at the National Center for Biotechnology Information (NCBI) using sequence search tools. database such as the Basic Local Alignment Tool (BLAST) (Altschul et al. (1990) J. Mol. Biol. 215: 403-410; and Altschul et al. (1997) Nucleic Acids Res. 25: 3389- 3402). The program was used to find regions of local similarity between sequences by comparing the nucleic acid or polypeptide sequences with sequence database and by calculating the statistical significance of correspondences. ' For example, the polypeptide encoded by the nucleic acid of SEQ ID NO: 1 was used for the TBLASTN algorithm, with default settings and the filter to ignore lag of low complexity sequences. The output of the analysis was considered by comparison in pairs, and classified according to the probability rating (E value), where the result reflects the probability that a particular alignment occurs randomly (the lower the E value, the greater the significance of the result). In addition to E-values, comparisons were also qualified by percentage identity. Percent identity refers to the number of identical nucleotides (or amino acids) between the two compared nucleic acid sequences (or polypeptide) in a particular segment. In some cases, the default parameters can be adjusted to modify the strictness of the search. For example, the value E can be increased to show less strict correspondences. In this way you can identify almost exact short correspondences. Table A below gives a list of nucleic acid sequences related to the nucleic acid sequence of SEQ ID NO: 1. Table A: Examples of sequences related to the nucleic acid sequence of SEQ ID NO: 1 Contig compiled from several EST accesses (the main ones are shown); The quality of EST sequencing is usually low so some nucleic acid substitutions can be expected. The sequences of Daucus carota and Glycine max have been corrected in comparison with their access number. Example 2: Alignment of hox5 polypeptide sequences of HDZip class I AlignX of Vector NTI (Invitrogen) was used based on the popular Clustal algorithm of progressive alignment (Thompson et al. (1997) Nucleic Acids Res 25: 4876-4882; Chenna et al. (2003). Nucleic Acids Res 31: 3497 -3500). A phylogenetic tree can be constructed using a neighbor-joining grouping algorithm. Default values are 10 for the space opening penalty, 0.1 for the space extension penalty, and the selected weight matrix is Blosum 62 (if polypeptides are aligned). The result of the multiple sequence alignment is shown in Figure 2. The three main domains characterized, from the N-terminus to the C-terminus, are in strong frames and identified as the acidic box, the class I homeodomain and the closure of six heptad leucine. The "Conserved Domain" comprises these three domains. Additionally, the Trp tail and the RPFF amino acid motif are in light boxes. Example 3: Calculation of global percentage identity between hoxd polypeptide sequences of HDZIp class I Global percentages of similarity and identity were determined between full length class I HDZip hox5 polypeptide sequences using the Matrix Global Alignment Tool (MatGAT) software (BMC Bioinformatics, 2003 4:29) MatGAT: an application that generates similarity / identity matrices using DNA or protein sequences.

Campanella JJ, Bitincka L, Smalley J; software hosted by Ledion Bitincka). The MatGAT software generates similarity / identity matrices for protein or DNA sequences without the need for pre-alignment of the data. The program performs a series of alignments in pairs using the global alignment algorithm of Myers and Miller (with a space opening penalty of 12, and a space extension penalty of 2), calculates similarity and identity using for example Blosum 62 (for polypeptides), and then place the results in a distance matrix. The sequence similarity is shown in the lower half of the dividing line and the sequence identity is shown in the upper half of the diagonal dividing line. The parameters used in the comparison were: Rating matrix: Blosum 62 First space: 12 Space extension: 2 The results of the software analysis are shown in Table Bl for global similarity and identity over the entire length of the polypeptide sequence (excluding partial polypeptide sequences). The percentage identity is provided above the diagonal and the percentage similarity is provided below the diagonal. The percentage identity between the polypeptide sequences shown can be as low as 29% identity of amino acids compared to SEQ ID NO: 2. Table B 1: MatGAT results for overall similarity and identity throughout the polypeptide sequences.

The "Conserved Domain" of the hox5 polypeptide sequences of HDZip class I comprises from the N-terminus to the C-terminus, an acidic box, a class I homeodomain and the leucine closure of six heptad (see Figure 2), compliance with what is defined above. When a percentage identity analysis is carried out on the conserved domains instead of performing said analysis on the sequences of full-length polypeptides, an increase in the percentage identity is observed, as can be seen in Table B2. The lower values are now above 50% amino acid identity compared to SEQ ID NO: 2. Table B 2: MatGAT results for overall similarity and identity in the "Conserved Domain" of the polypeptide sequences.

Example 4: Identification of domains that are comprised in HDxip class I hoxd polypeptide sequences The Integrated Resource of Protein Families, Domains and Sites (InterPro) database is an integrated interface for signature databases commonly used for searches based on text and search based on sequence. The InterPro database combines these databases, which use different methodologies and various degrees of biological information on well-characterized proteins to derive protein signatures. Collaborating databases include SWISS-PROT, PROSITE, TrEMBL, PRINTS, ProDom and Pfam, Smart and TIGRFAMs. Interpro is hosted by the European Bioinformatics Institute in the United Kingdom. The results of the InterPro scan of the polypeptide sequence represented by SEQ ID NO: 2 are presented in Table C. Table C: InterPro scan results of the polypeptide sequence represented by SEQ ID NO: 2 The composition of primary amino acids (in percent) to determine whether a polypeptide domain is rich in specific amino acids (eg, in an acidic box) can be calculated using ExPASy server software programs, in particular the ProtParam tool (Gasteiger E et al. (2003) ExPASy: the preomic server for in-depth protein knowledge and analysis.

Acids Res 31: 3784-3788). The composition of the polypeptide sequence of interest can then be compared with the Average amino acid composition (in%) in the Swiss-Prot Protein Sequences database. In the Table below (Table D), the% Asp (D),% Glu is compared (E) and its combined content in the acid table of SEQ ID NO: 2 with the mean of the protein sequence database Swiss-Prot. Table D An acidic picture can be part of a transcription activation domain. Eukaryotic transcription activation domains have been classified according to their amino acid content, and major categories include acid, glutamine-rich and proline-rich activation domains (Rutherford et al. (2005) Plant J. 43 (5) 769-88, and references there). The Gene Ontology (GO) Consortium is an international collaboration between scientists in several biological databases, with an Editorial Office based at the European Bioinformatics Institute. The goal of GO is to provide a controlled vocabulary for the description of the function molecular, biological process and cellular component of gene products. When an InterPro scan is performed in accordance with what is described above, the GO database is also searched. Hox5 polypeptide sequences of HDZip class I have a transcription factor of molecular function and a sequence-specific DNA binding activity, and are located in the nucleus of the plant cell (see Table below (Table E)). Table E Example 5: Prediction of Hox5 polypeptide sequence topology of HDZip class I A leucine closure prediction and identification of heptad was performed using specialized software such as 2ZIP, which combines a standard super-helix prediction algorithm with a search approximate characteristic leucine repeat (Bornberg-Bauer et al. (1998) Nucleic Acids Res 26 (11): 2740- 2746, hosted by Max Planck Institut, Golm in Germany). A potential leucine closure, a leucine repeat or a Super-helix can be identified using this software. Hox5 polypeptide sequences of HDZip class I comprise a prediction of leucine closure with at least five haptens, preferably six heptates. When the polypeptide of SEQ ID NO: 2 is subjected to this algorithm, a potential leucine closure is found between positions 143 and 178, as shown in the output below (the numbers reflect the position of amino acids, dC the region of super -helix, and L the leucine inside the heptad): MDPGRVVFDSGVARRACPGGAQML FGGGGSANSGGFFRGVPAAVLGMDESRSSSSAAGA 61 71 81 91 101 111 121 131 GAKRPFFTTHEELLEEEYYDEQAPEKKRRLTAEQVQMLERSFEEENKLEPERKTELARRL 141151161171 GMAPRQVAVWFQNRRARWKTKQLEHDFDRLKAAYDALAADHHALLSDNDRLRAQVISLTE CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC LZLZLZLZLZLZLZLZLZLZLZLZLZLZLZLZLZLZ 181 191 201 211 221 231 241 251 KLQDKETSPSSATITTAAQEVDQPDEHTEAASTTGFATVDGALAAPPPGHQQPPHKDDLV CCCCCCCC 261271281291 301311321331 SSGGTNDDGDGGAAWVFDVTEGANDRLSCESAYFADAAEAYERDCAGHYALSSEEEDGG 341 AVSDEGCSFDLPDAAAAAAAMFGAAGWHHDAADDEEAQLGS TAWFWS Example 6: Assay for Hox5 polypeptide sequences of HDZip class I Hox5 polypeptides of HDZip class I or homologues of the they have a DNA binding activity, preferably in the semi-sites of 5 base pairs that are spliced in a central position, CAA (A / T) ATTG, in accordance with that detected in tests of a yeast hybrid (Meijer et al. (2000) Mol Gen Genet 263: 12-21). In transient assays in rice cell suspensions, the co-bombardment of a Hox5 HDZip class I polypeptide with the GUS reporter gene supposedly resulted in an increased number of stained spots, which were also more intense in color (Meijer et al, supra). This assay is useful to demonstrate the function of activator of hox5 polypeptides of HDZip class I or homologs. Example 7: Cloning of hox5 nucleic acid sequence from HDZip class I of Oryza sativa The nucleic acid sequence hox5 of HDZip class I from Oryza sa tiva was amplified by polymerase chain reaction using a seedling cDNA library as a template of Oryza sativa (Invitrogen, Paisley, United Kingdom). After reverse transcription of RNA extracted from the seedlings, the cDNAs were cloned into pCMV Sport 6.0. The average size of the insert of the bank was 1.6 kb and the original number of clones was of the order of 1.67xl07 ufe. The original titer was determined at 3.34 x 10 6 cfu / ml after the first amplification of 6x10 0 cfu / ml. After plasmid extraction, 200 ng of tempering was used in a polymerase chain reaction mixture of 50 μl. The primers prm06000 (SEQ ID NO: 34; sense, initial codon in bold, AttBl site in italics: 5'- GGGGACAAGGGGGGACAAAAAAGCAGGCTTAAACAATGGATCCCGGCCG 3 ') and prmOdOOl (SEQ ID NO: 35; reverse, complementary, site AttB2 in italics: 5' GGGGACCACGGGGGACAAGAAAGC? GGGTGATCAGCTCCAGAACCAGG 3 '), which include the AttB sites for Gateway recombination, were used for amplification by polymerase chain reaction. The polymerase chain reaction was performed using Hifi Taq DNA polymerase under standard conditions. A polymerase chain reaction fragment of 1116 base pairs (including attB sites from start to finish 1050 base pairs) was also amplified and purified using standard methods} . The first step of the Gateway procedure, the BP reaction, was then carried out, during which the polymerase chain reaction fragment recombines in vivo with the plasmid pDONR201 to produce, in accordance with the Gateway terminology, an "entry clone". Plasmid pDONR201 was purchased from Invitrogen, as part of the Gateway® technology. Example 8: Construction of Vector The input clone comprising the nucleic acid sequences was subsequently used in an LR reaction with a "target" vector used for the transformation from Oryza sa tiva. This vector contained as functional elements within the borders of T-DNA: a selectable plant marker; a screened marker expression cassette; and a Gateway cassette contemplated for LR in vivo recombination with the sequence of interest already cloned in the input clone. A rice GOS2 promoter (SEQ ID NO: 33 or SEQ ID NO: 178) for constitutive expression was located upstream of this Gateway cassette. After the LR recombination step, the resulting expression vector (Figure 3) was transformed into Agrobacterium strain LBA4044 in accordance with methods well known in the art. Example 9: Transformation of Rice Transformation Plant The Agrobacterium that contains the expression vector was used to transform Oryza sa tiva plants. The rind of mature dry seeds of the Nipponbare Japanese rice variety was removed. Sterilization was performed by incubation for 1 minute in 70% ethanol, followed by 30 minutes in 0.2% HgC12, followed by washing 6 times 15 minutes with sterile distilled water. The sterile seeds were then germinated in a medium containing 2,4-D (means of callus induction). After incubation in the dark for four weeks, embryogenic calli derived from scutellum were cut and propagated in the same medium. After two weeks, the calluses were multiplied and propagated by subculture in the same medium for an additional 2 weeks. Embryogenic callus pieces were subcultured in fresh medium 3 days before co-culture (to reinforce cell division activity). Agrobacterium strain LBA4404 containing the expression vector was used for co-culture. Agrobacterium was inoculated in AB medium with the appropriate antibiotics and cultured for 3 days at a temperature of 28 ° C. The bacteria were then harvested and suspended in a liquid co-culture medium at a density (OD600) of about 1. The suspension was then transferred into a Petri dish and the calli immersed in the suspension for 15 minutes. The callus tissues were then dried on filter paper and transferred to a solidified coculture medium and incubated for 3 days in the dark at a temperature of 25 ° C. The co-cultured canoes were cultured in medium containing 2,4-D for 4 weeks in the dark at a temperature of 28 ° C in the presence of a selection agent. During this period, fast-growing resistant callus islands were developed. After the transfer of this material to a medium of regeneration and incubation in the dark, the embryogenic potential was released and shoots developed over the next four to five weeks. The shoots were cut from the corns and incubated for 2 to 3 weeks in a medium containing auxin from which they were transferred to the soil. The hardened buds were grown under conditions of high humidity and short days in a greenhouse. Approximately 35 independent TO rice transformants were generated for a construct. The primary transformants were transferred from a tissue culture chamber to a greenhouse. After a quantitative polymerase chain reaction analysis to verify the number of T-DNA insert copies, only single-copy transgenic plants that exhibited tolerance to the selection agent were conserved for IT seed harvest. The seeds were then harvested three to five months after the transplant. The method provided individual locus transformants at a rate of more than 50% (Aldemita and Hodges 1996, Chan et al., 1993, Hiei et al., 1994). Example 10: Phenotypic evaluation procedure 10.1 Evaluation conditions About 35 independent TO rice transformants were generated. The primary transformants were transferred from a tissue culture chamber to a greenhouse for growth and harvest of IT seed. Seven events were conserved, among which the IT progeny segregated 3: 1 for presence / absence of the transgene. For each One of these events was selected by visual marker expression monitoring approximately 10 IT seedlings containing the transgene (heterozygous and homozygous) and approximately 10 IT seedlings that did not have the transgene (nullizygotes). The transgenic plants and the corresponding nullizygotes were grown side by side in random positions. The greenhouse conditions were short days (12 hours of light), temperature 28 ° C in the light and 22 ° C in the dark, and a relative humidity of 70%. All TI events were evaluated additionally and generation T2 followed the same evaluation procedure as in the case of the Ti generation. From the stage of sowing until the stage of maturity, the plants passed several times through a cabinet of digital images. At each point of time, digital images (2048x1536 pixels, 16 million colors) of each plant were taken from at least six different angles. Salt Stress Screening 4-event plants (T2 seeds) were grown on a substrate made of coconut and argex fibers (3 to 1 ratio). A normal nutrient solution was used during the first two weeks after the transplant of the small plants in the greenhouse. After the first two weeks, 25 mM of salt (NaCl) was added to the nutrient solution, until the plants were harvested.

Drought Screening Five-event plants (T2 seeds) were grown on potting soil under normal conditions until they approached the spike stage. They were then transferred to a "dry" section where irrigation was removed. Moisture probes were inserted in randomly selected pots to monitor soil water content (SWC). When the water content of the soil was below certain limits, the plants were automatically watered again continuously until reaching a normal level again. The plants were then transferred again to normal conditions. The rest of the crop (plant maturation, seed harvest) was the same as in the case of non-cultivated plants under conditions of abiotic stress. A confirmation round was carried out which consisted in the repetition of the screening with non-harvested T2 seeds of plants from the first drought screening, but of plants grown under normal conditions. Screening of reduced nutrient availability (nitrogen) Rice plants are grown in potting soil under normal conditions except for the nutrient solution. The pots are watered from the transplant until the maturation with a solution of specific nutrient that contained a reduced content of nitrogen (N), usually between 7 and 8 times less. The rest of the cropd D (plant maturation, seed harvest) is the same as for plants not cultivated under abiotic stress. Parameters related to seed are then measured. 10.2 Statistical analysis: F test An ANOVA (variant analysis) of factor two was used as a statistical model for the overall evaluation of the phenotypic characteristics of the plants. An F test was carried out on all the measured parameters of all the plants of all events transformed with the gene of the present invention. The F test was carried out to review an effect of the gene on the totality of the transformation events and to verify the global effect of the gene that is also known as the global gene effect. The significance threshold for a true global gene effect was established at a 5% probability level for the F test. A significant F test value indicates a gene effect, which means that it is not only the simple presence or position of the gene which is causing the differences in phenotype. 10.3 Measured parameters 10.3.1 Measurement of parameters related to biomass From the stage of sowing to the stage of maturity, the plants were passed several times through a digital image cabinet. At each point of time, digital images were taken (2048x1536 pixels, 16 million colors) of each plant from at least six different angles. The area above the ground of the plant (or leaf biomass) was determined by counting the total number of pixels in the digital images of the parts of plants above the ground discriminated from the bottom. This value was averaged for the image taken at the same time point from different angles and was converted to a physical surface value expressed in square millimeters per calibration. Experiments show that the above-ground floor area measured in this way correlates with the biomass of plant parts above ground. The area above the ground is the point of time at which the plant has reached its maximum leaf biomass. Early vigor is the area above the soil of the plant (seedling) three weeks after germination. An additional parameter was used to measure tolerance to abiotic stress if necessary: the Green Index after drought that provides an indication of senescence of the plant. It is the proportion (expressed as a percentage) of yellow pixels in the first image after the drought. To measure parameters related to roots, plants were cultivated in pots specially designed with transparent backgrounds to allow the visualization of the roots.

A digital camera recorded images through the bottom of the pot during the growth of the plant. Root characteristics such as total projected area (which can be correlated with total root volume), average diameter and root length above a certain thickness threshold (thick root length, or coarse root length) were deducted from the image using appropriate software. The increase in root biomass is expressed in an increase in total root biomass (according to what is measured as maximum root biomass observed during the life of a plant); or as an increase of the root / shoot index (according to what is measured as the ratio between the root mass and the shoot mass in the period of active root and shoot growth). 10.3.2 Parameter measurements related to seeds The mature primary panicles were harvested, counted, bagged, labeled with a bar code and then dried for three days in an oven at a temperature of 37 ° C. The panicles were then shelled and all the seeds were collected and counted. The filled shells were separated from the empty shells using an air blowing device. The empty shells were discarded and the remaining fraction was counted again. The full husks were weighed on an analytical scale. The number of filled seeds was determined by counting the number of full shells that remained after the separation step. The total seed yield was measured by weighing all the full husks harvested from a plant. The total number of seeds per plant was measured by counting the number of peels harvested from a plant. The Thousand Grains Weight (TKW) was extrapolated from the number of seeds filled, counted and their total weight. The Harvest Index (Hl) in the present invention is defined as the ratio between the total yield of seed and the area above the ground (mm2) multiplied by a factor of 106. The total number of flowers per panicle according to that defined in the present invention is the ratio between the total number of seeds and the number of mature primary panicles. The seed filling rate according to that defined in the present invention is the ratio (expressed as a percentage) between the number of filled seeds and the total number of seeds (or florets). Example 11: Results of transgenic rice plants expressing a hox5 nucleic acid of HDZip class I under normal growth conditions The results of the evaluation of transgenic rice plants expressing the hox5 nucleic acid of HDZip class I under normal conditions of growth are presented in Table F. The percentage difference between the transgenic and the corresponding nullizygotes is shown, with a P value from the F test below 0.05. Table F: Results of the evaluation of transgenic rice plants expressing a hox5 nucleic acid of HDZip class I under normal growth conditions Example 12: Results of transgenic rice plants expressing the nucleic acid sequence useful in carrying out the methods of the present invention, under growth conditions in salt stress The results of the evaluation of transgenic rice plants expressing the acid nucleic acid encoding a hox5 polypeptide sequence of HDZip class I Salt stress growth conditions are presented in Table G. The percentage difference between the transgenic and the corresponding nullizygotes is shown, with a P value from the F test below 0.05. Table G: Result of the evaluation of transgenic rice plants expressing the hox5 nucleic acid of HDZip class I under salt stress growth conditions.

Example 13: Results of transgenic rice plants expressing the hox5 nucleic acid of HDZip class I under drought stress growth conditions The results of the evaluation of transgenic rice plants expressing the nucleic acid sequence useful in the embodiment of the methods of the present invention under drought stress growth conditions are presented in Table H. The percentage difference between the transgenic and the corresponding nullizygotes is shown, with a P value from the F test lower than 0.05. Table H: Results of the evaluation of transgenic rice plants expressing the nucleic acid sequence useful in carrying out the methods of the invention, under conditions of drought stress growth.

EXAMPLES NRT polypeptides and encoding nucleic acids Example 14: Identification of sequences related to SEQ ID NO: 52 and SEQ ID NO: 53 Sequences (full-length cDNA, ESTs or genomic) related to SEQ ID NO: 52 and / or sequences of proteins related to SEQ ID NO: 53 were identified among those maintained in the Entrez Nucleotides database at the National Center for Biotechnology Information (NCBI) using the basic sequence search tools of data, such as the Basic Local Alignment Tool (BLAST) (Altschul et al. (1990) J. Mol. Biol. 215: 403-410; and Altschul et al. (1997) Nucleic Acids Res. 25: 3389- 3402). The program is used for regions of local similarity between sequences by comparing polypeptide or nucleic acid sequences with sequence databases and by calculating the statistical significance of the correspondences. The polypeptide encoded by SEQ ID NO: 52 was used for the TBLASTN algorithm, with default settings and the filter to ignore variations of low complexity sequences. The output of the analysis was considered by comparison in pairs, and classified according to the probability result (E value), where the result reflects the probability that a particular alignment occurs randomly (the smaller the E value, the more significant). it is the result) . In addition to E-values, comparisons were also qualified by percentage identity. Percent identity refers to the number of identical nucleotides (or amino acids) between the two nucleic acid sequences compared (or polypeptides) in a particular segment. In certain cases, the default parameters can be adjusted in order to modify the strictness of the search. In addition to the publicly available nucleic acid sequences found in NCBI, databases of Own sequences are also searched following the same procedure as the procedure described above. Table I provides a list of protein and nucleic acid sequences related to the nucleic acid sequence represented by SEQ ID NO: 1 and the protein sequence represented by SEQ ID NO: 2. Table I: Nucleic acid sequences related to the nucleic acid sequence (SEQ ID NO: 1) useful in the methods of the present invention, and the corresponding deduced polypeptides.

Example 15: Aligning sequences of relevant AlignX polypeptides of Vector NTI (Invitrogen) is based on the popular Clustal algorithm of progressive alignment (Thompson et al (1997) Nucleic Acids Res 25: 4876-4882; Chenna et al. (2003) Nucleic Acids Res 31: 3497-3500). A phylogenetic tree can be constructed using a neighbor-joining grouping algorithm. Default values are a penalty of 10 for space opening, a penalty of 0.1 for space extension and the selected weighting matrix is Blosum 62 (if polypeptides are aligned). The result of multiple sequence alignment using relevant polypeptides in the identification of the tools for carrying out the methods of the present invention is shown in Figures 6 (a) and (b) of the present application. The multiple alignment shows the high conservation of sequences between NRT proteins of the various species. Proteins comprising a PTR2 domain (and implemented by SEQ ID NO: 126) clearly do not fall within the group of NRT proteins as defined herein. Example 16: Overall percentage identity calculation between NRT polypeptide sequences Global percentages of similarity and identity between sequences of full-length polypeptides useful in carrying out the methods of the present invention were determined using the MatGAT (Matrix Global Alignment Tool) software ( BMC Bioinformatics, 2003 4:29 MatGAT: an application that generates similarity / identity matrices using protein or DNA sequences Campanella JJ, Bitincka L, Smalley J, software hosted by Ledion Bitíncka). The MatGAT software generates similarity / identity matrices for DNA or protein sequences without the need for pre-alignment of the data. The program performs a series of alignments in pairs using the global alignment algorithm of Myers and Miller (with a space-opening penalty of 12, and a space-extension penalty of 2), calculates the similarity and identity using for example Blosum 62 (for polypeptides), and then place the results in a distance matrix. A sequence similarity is shown in the lower half of the dividing line and a sequence identity is shown in the upper half of the diagonal dividing line. Parameters used in the comparison were: Qualification matrix: Blosum62 First space: 12 Space extension: 2 The results of the software analysis are presented in Table 1 for global similarity and identity throughout the polypeptide sequences (excluding the sequences of partial polypeptides). The percentage identity is provided above the diagonal and the percentage similarity is provided down the diagonal. The percentage identity between the polypeptide sequences useful for carrying out the methods of the present invention is usually higher than an amino acid identity of 60% compared to SEQ ID NO: 53 (although exceptions occur); whereas proteins comprising a PTR2 domain (such as for example rice nitrate transporter represented by SEQ ID NO: 126, row 31 in the Table below) show only a very limited sequence identity with NRT proteins (17% or less) .

Table J: MatGAT results for global similarity and identity throughout the polypeptide sequences in Example 17: Identification of domains comprised in polypeptide sequences useful for carrying out the methods of the invention The Integrated Resource of Protein Families database, Domains and Sites (InterPro) is an integrated interface for signature databases commonly used for text-based searches and sequence-based searches. The InterPro database combines these databases that use different methodologies and various degrees of biological information on well-characterized proteins to derive protein signatures. The collaborating databases include SWISS-PROT, PROSITE, TrEMBL, PRINTS, ProDom and Pfam, Smart and TIGRFAMs. Interpro is hosted at the European Bioinformatics Institute in the United Kingdom. The results of the InterPro scan of the polypeptide sequences according to that represented by SEQ ID NO: 53 are presented in Table K. Table K: InterPro scan results of the polypeptide sequence represented by SEQ ID NO: 53 Example 18: Topology prediction of NRT polypeptides (subcellular, transmembrane localization) TargetP 1.1 predicts subcellular protein localization eukaryotic Location assignment is based on the predicted presence of any of the N-terminal pre-sequences: chloroplast transit peptide (cTP), mitochondrial focus peptide (mTP) or secretory pathway signal peptide (SP). The results on which the final prediction is based are not really probabilities, and do not necessarily add one. However, the location with the highest result is the most likely according to TargetP, and the relationship between the results (the reliability class) can be an indication of the accuracy of the prediction. The reliability class (RC) is within a range of 1 to 5, where 1 indicates the strongest prediction. TargetP is maintained on the server of the Center for Biological Sequence Analysis, Technical University of Denmar. For sequences predicted to contain an N-terminal pre-sequence, a potential dissociation site can also be predicted. Numerous parameters were selected, such as organism group (no plant or plant), cutoff adjustments (none, predefined cutoff adjustment, or cutoff adjustment specified by the user), and calculation of prediction of dissociation sites (yes or not) . The results of TargetP 1.1 analysis of the polypeptide sequence represented by SEQ ID NO: 53 are presented in Table L. The organism group "plant" has been selected, no cut has been defined, and the predicted length of the transit peptide required. No sub-cellular location could be predicted. Table L: TargetP 1.1 analysis of the polypeptide sequence according to that represented by SEQ ID NO: 53 Many other algorithms can be used to perform such analyzes, including: • ChloroP 1.1 hosted on the server of the Technical University of Denmark; • Protein Prowler Subcellular Localisation Predictor version 1.2 hosted on the server of the Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia; PENCE Proteome Analyst PA-GOSUB 2.5 hosted on the server at the University of Alberta, Edmonton, Alberta, Canada.

Using the TMHMM program (Center for Biological Sequence Analysis, Technical University of Denmark) it was predicted that the number of transmembrane helices was 11, see Table M below. Table M: The expected number of amino acids in transmembrane helices was predicted in at least 242 (if it is greater than 18, the protein is most likely a transmembrane protein). In addition, the presence of a secretion signal is not very likely, since there is no predicted transmembrane helix within the first 60 amino acids, nor a N-terminal signal sequence (Exp number, first 60 AAs: 0.00085). Example 19: Test for NRT To determine the transport activity of NRT, the nitrate absorption test was carried out in accordance with that described by Tong et al. (Plant J. 41, 442-450, 2005). Briefly, mRNA is prepared from constructs in which the ORF encoding the NRT protein of interest is preceded by 5'-UTR of the ß-globin gene of Xenopus and followed by 3'-UTR of the same gene. This mRNA is injected into stage V and VI oocytes of Xenopus after which the NRT protein of interest is expressed. The oocytes are incubated in a solution with 15N03"for 3 to 12 hours at a temperature of 18 ° C. After that, the oocytes are washed and dried at 60 ° C.

Nitrate absorption enriched with 15N is measured by measuring the 15N / 14N ratio with a mass spectrometer. Other suitable assays for measuring the uptake of N03 are recognized by those skilled in the art, see, for example Filleur et al (absorption of 15N03 ~ in roots, FEBS Letters 489, 220-224, 2001), or Zhou et al (current measurement caused by anions with the two-electrode voltage fixation method, J. Biol. Chem. 275, 39894-39899, 2000). If required, a nar2 gene can be co-expressed in order to increase nitrate transport. Alternatively, the activity of an NRT protein or homologue thereof can be assayed by expression of the NRT protein or homologue thereof under the control of a G0S2 promoter in the Oryza sa tiva Nipponbare species, which results in plants with a Increased soil biomass and / or increased seed yield compared to corresponding wild type plants. This increase in seed yield can be measured in several ways, such as an increase in the total weight of seeds, number of seeds filled or total number of seeds, such as an increase in the harvest index or an increase in flowers per panicle. . Example 20: Cloning of nucleic acid sequence according to that represented by SEQ ID NO: 52 The NRT gene from Oryza sativa was amplified by polymerase chain reaction using a cDNA library from Oryza sa tiva seedlings (Invitrogen, Paisley, United Kingdom) as a template. After reverse transcription of RNA extracted from seedlings, the cDNAs were cloned into pCMV Sport 6.0. The average size of the inserts of the bank was 1.5 kb and the original number of clones was of the order of 1.59 x 107 ufe. The original titre was determined at 9.6 x 105 cfu / ml after the first amplification of 6 x 10 11 cfu / ml. After plasmid extraction, 200 ng of annealing was used in a 50 μl PCR mixture. The primers prm07061 (SEQ ID NO: 54, sense, initial codon in bold, site AttBl in italics: 5'-ggggacaagtttgtacaaaaaagcaggcttaaacaatggactcgtcgacggtg-3 ') and prm07062 (SEQ ID NO: 55 reverse, were used for amplification by polymerase chain reaction. complementary, Bold termination codon, AttB2 site in italics: 5'-ggggaccactttgtacaagaaagctgggtctcggtcgcagaattgtttac-3 '), which include the AttB sites for Gateway recombination. A polymerase chain reaction was performed using Hifi Taq DNA polymerase under standard conditions. A fragment of polymerase chain reaction of 1683 base pairs (including AttB sites) was amplified and purified using standard methods as well. The first stage of the Gateway procedure, the BP reaction, was carried out then, during which the polymerase chain reaction fragment recombines in vivo with the plasmid pDONR201 to produce, according to the Gateway terminology, an "entry clone". Plasmid pDONR201 was purchased from Invitrogen, as part of the Gateway® technology. Example 21: Construction of expression vector using the nucleic acid sequence represented by SEQ ID NO: 52 The input clone was subsequently used in the LR reaction with a target vector used for the transformation of Oryza sa tiva. This vector contains as functional elements within the borders of T-DNA: a selectable plant marker; a screened marker expression cassette; and a Gateway cassette contemplated for in vivo recombination of LR with the sequence of interest already cloned in the input clone. A rice GOS promoter (nucleotides 1 to 2188 of SEQ ID NO: 56, the promoter-gene combination) for constitutive expression was located upstream of this Gateway cassette. After the step of LR recombination, the resulting expression vector for NRT (Figure 7) was transformed into the LBA4044 strain of Agrobacterium and subsequently into Oriza sativa plants. Example 22: Transformation of Plants The Agrobacterium that contains the expression vector was used to transform Oriza sa tiva plants. HE They removed the husks from the mature dried seeds of the Japanese rice species Nipponbare. Sterilization was performed by incubation for one minute in 70% ethanol followed by 30 minutes in 0.2% HgCl2, followed by six 15 minute washes with sterile distilled water. The sterile seeds were then germinated in a medium containing 2,4-D (callus induction medium). After incubation in the dark for 4 weeks, scrapie-derived tripe, embryogenic were cut and propagated in the same medium. After two weeks, the calluses were multiplied or propagated by subculture in the same medium for two additional weeks. Embryogenic callus pieces were subcultured in fresh medium 3 days before co-culture (to reinforce cell division activity). Agrobacterium strain LBA4404 containing the expression vector was used for co-culture. Agrobacterium was inoculated in AB medium with the appropriate antibiotics and cultured for 3 days at a temperature of 28 ° C. The bacteria were then harvested and suspended in liquid co-culture medium at a density (OD600) of approximately 1. The suspension was then transferred to a Petri dish and the tripe was submerged in the suspension for 15 minutes. The tissues of the calluses were then dried on filter paper and transferred to a co-culture medium, solidified, and incubated for 3 days in the dark at a temperature of 25 ° C. The co-cultured calli were cultured in a medium containing 2,4-D for 4 weeks in the dark at a temperature of 28 ° C in the presence of a selection agent. During this period, islands of resistant calluses of rapid growth were developed. After the transfer of this material to a medium of regeneration and incubation in the light, the embryogenic potential was released and batches were developed in the following 4 to 5 weeks. The shoots were cut from the calluses and incubated for 2 to 3 weeks in a medium containing auxin from which they were transferred to the soil. Hardened shoots were grown under high humidity and short days in a greenhouse. Approximately 35 independent TO rice transformants were generated for a construct. The primary transformants were transferred from a tissue culture chamber to a greenhouse. After a quantitative polymerase chain reaction analysis to verify the number of copies of the T-DNA insert, only single copy transgenic plants exhibiting tolerance to the selection agent were conserved for IT seed harvest. The seeds were then harvested 3 to 5 months after the transplant. The method provided single locus transformant at a rate of more than 50% (Aldemita and Hodges 1996, Hiei et al., 1994). Example 23: Phenotypic Evaluation Procedure 23.1 Evaluation Conditions Approximately 30 independent TO rice transformants were generated. The primary transformants were transferred from a tissue culture chamber to a greenhouse for cultivation and harvesting of IT seeds. Five elements, from which the IT progeny segregated 3: 1 for presence / absence of transgene, were retained. For each of these events, approximately 10 IT seedlings containing the transgene (heterozygous and homozygous) and approximately 10 IT seedlings without the transgene (nullizygotes) were selected by visual marker expression monitoring. The transgenic plants and the corresponding nullizygotes were grown side by side in random positions under the following environmental conditions: photoperiod = 11.5 hours, daylight intensity = 30,000 lux or more, daylight temperature = 28 ° C or more , night temperature = 22 ° C, relative humidity = 60-70%. Four IT events were evaluated additionally in the T2 generation following the same evaluation procedure as for the TI generation but with more individuals per event. From the stage of sowing until the stage of maturity, the plants were passed several times through a cabinet of digital images. At each point of time Digital images (2048 x 1536 pixels, 16 million colors) were taken from each floor of at least 6 different angles. 23.2 Statistical Analysis An ANOVA (variant analysis) was used in the factors as a statistical model for the global evaluation of the phenotypic characteristics of the plants. An F test was carried out on all the measured parameters of all the plants of all the events transformed with the gene of the present invention. The F test was carried out to review an effect of the gene on the totality of the transformation events to verify the overall effect of the gene, which is also known as the global gene effect. The significance threshold for a true global gene effect was established at a 5% probability level for the F test. A significant F test value points to a gene effect, which means that it is not just the simple presence or position of the gene. gene that is causing the differences in phenotype. To review an effect of the genes within an event, that is, for a specific effect for line, a T test was performed within each event using data sets from the transgenic plants and the corresponding null plants. The terms "null plants" or "null segregantes" or "nulicigotos" are the treated plants of the same way that the transgenic plant, but of which the transgene has been segregated. Null plants can also be described as the homozygous negative transformed plants. The threshold for significance for the T test is set at a probability level of 10%. The results for certain events can be above or below this threshold. This is based on the hypothesis that a gene can have only one effect in certain positions in the genome and that the occurrence of this effect of slope of the position is common. This type of gene effect is also known here as "gene line effect". The value T is obtained by comparing the value T with the distribution T or alternatively, comparing the value F with the distribution F. The value P then provides the probability that the null hypothesis (that is, there is no transgene effect) is correct. Since there were two experiments with splicing events, a combined analysis was carried out. This is useful to review the consistency of the effects on new experiments, and if so, to accumulate evidence from both experiments in order to increase confidence in the conclusion. The method used was a mixed model approach that takes into account the multilevel structure of the data (ie, experiment-event-segregant). P values are obtained by comparing the proof of the proportion of probability with chi square distributions. 23.3 Measured Parameters Measurement of parameters in relation to the biomass From the stage of sowing until the stage of maturity, the plants passed several times through a cabinet of digital images. At each point of time, digital images (2048 x 1536 pixels, 16 million colors) of each plant were taken from at least 6 different angles. The area above the soil of the plants (or leaf biomass) was determined by counting the total number of pixels in the digital images of the parts of the plant above the ground discriminated from the bottom. This value was averaged from the images taken at the same time point from the different angles and was converted into a physical surface value expressed in square mm per calibration. The experiments show that the above-ground floor area measured in this way correlates with the biomass of plant parts above the ground. The area above the ground is the point of time at which the plant has reached its maximum leaf biomass. The initial vigor is the area above the soil of the plant (seedling) 3 weeks after germination. Parameter measurements related to seeds The mature primary panicles were harvested, counted, bagged, labeled with bar code and then dried for 3 days in an oven at a temperature of 37 ° C. The panicles were then shelled and all the seeds were collected and counted. The filled shells were separated from the empty shells using an air blowing device. The empty peels were discarded and the remaining fraction was counted again. The full husks were weighed on an analytical scale. The number of filled seeds was determined by counting the number of full shells that remained after the separation step. The total seed yield was measured by weighing all the full husks harvested from a plant. The total number of seeds per plant was measured by counting the number of peels harvested from a plant. The thousand grain weight (TKW) is extrapolated from the number of filled seeds counted and their total weight. The Harvest index (Hl) in the present invention is defined as the ratio between the total yield of seeds and the area above the ground (mm2), multiplied by a factor of 106. The total number of flowers per panicle in accordance with defined in the present invention is the ratio between the total number of seeds and the number of mature primary panicles. The seed filling rate is defined in the present invention as the ratio (expressed as a percentage) of the number of seeds filled and the total number of seeds (or florets). Flowers per panicle is a parameter that estimates the average number of florets per panicle in a plant, which is derived from the number of total seeds divided by the number of first panicles. The highest panniculus and all the panicles that were joined with the highest panniculus when they are aligned vertically were considered as first panicles and were counted manually. Example 24: Results of the genotypic evaluation of the transgenic plants When analyzing the seeds in accordance with what was described above, the inventors found that plants transformed with the NRT gene construct had a higher seed yield, which is expressed as number of seeds filled (which may be at least partly the result of an increased fill rate), but total seed and Harvest Index, compared to plants that do not have the NRT transgene. The results obtained for plants in the TI generation are presented in summary form in Table N. Table N These positive results with seed yield were obtained again in the T2 generation. In Table O, data shows that the overall percentage increases for the number of seeds filled, the total weight of seeds and the harvest index, which are calculated from the data of the individual lines of generation T2, and P values respective. These T2 data were re-evaluated in a combined analysis with the results of the TI generation, and the P values obtained show that the observed effects were highly significant. Table O: In addition, the transgenic plants also showed an increase in biomes (max area: + 7% in the TI generation and + 4% in T2) that said increase was significant (P value of combined analysis: 0.0001). Examples YEP16 polypeptides and encoding nucleic acids Example 25: Gene cloning of nucleic acid encoding YEP16 from Arabidopsis thaliana The gene encoding YEP16 from Arabidopsis thaliana was amplified by polymerase chain reaction using a cDNA seedling library from Cryza sa as a template tiva (Invitrogen, Paisley, UK). After reverse transcription of the RNA extracted from the seedling, the cDNAs were cloned into pCMV Sport 6.0. The average size of the insert of the bank was 1.6 kb and the original number of clones was of the order of 1.6 x 107 ufe. The original titer was determined at 3.34 x 106 cfu / ml after the first amplification of 6 x 10 10 cfu / ml. After plasmid extraction, 200 ng of annealing was used in a 50 μl PCR mixture. For amplification by polymerase chain reaction primers prm00735 (SEQ ID NO: 144, sense, initial codon in bold letters, site AttBl in italics: 5 '-ggggacaagtttgtacaaaaaagcaggcttcacaatgga tactctctcagcatcc-3') and prm00736 (SEQ ID NO: 145; , complementary, site AttB2 in italics: 5'- ggggaccactttgtacaagaaagctgggttgtatca tcaagaaacccaga-3 '), which includes the AttB sites for Gateway recombination. Polymerase chain reaction was performed using Hifi Taq DNA polymerase under standard conditions. A polymerase chain reaction fragment of 12173 base pairs (including AttB sites, from start to completion: 1050 base pairs) was amplified and purified using standard methods as well. The first step of the Gateway procedure, the BP reaction, was then carried out, during which the polymerase chain reaction fragment in vivo with the plasmid pDONR201 to produce, according to the Gateway terminology, an "entry clone". Plasmid pDONR201 was purchased from Invitrogen, as part of the Gateway® technology. Example 26: Construction of Vector The input clone was subsequently used in an LR reaction with p00640, a target vector used for Oryza sa tiva transformation. This vector contains as functional elements within the limits of T-DNA: a selectable plant marker; a screened marker expression cassette; and a Gateway cassette contemplated for in vivo recombination of LR with the sequence of interest already cloned in the input clone. A rice oleosin promoter (SEQ ID NO: 143) for seed specific expression was located upstream of this Gateway cassette.

After the recombination step, the resulting expression vector (Figure 9) was transformed into strain LBA4044 of Agrobacterium and subsequently into Oriza sa tiva plants. The growth of transformed rice plants which were examined for the parameters described in Example 27 was allowed. Example 27: Evaluation and results of YEP16 coding nucleic acid from Oriza sativa under the control of the rice oleosin promoter under normal conditions of growth. Approximately 15 to 20 independent TO rice transformants were generated. The primary transformants were transferred from a tissue culture chamber to a greenhouse for growth and harvesting of Ti seed. Seven events, of which the TI progeny were segregated 3: 1 for the presence / absence of the transgene, were retained. For each of these events, approximately 10 IT seedlings containing the transgene (heterozygous and homozygous) and approximately 10 IT seedlings that did not have the transgene (nullizygotes) were selected by visual marker expression monitoring. Four IT events were evaluated additionally in the T2 generation following the same evaluation procedure as in the case of the TI generation but with more individuals per event. 27.1 Statistical analysis: Test F ANOVA (variant analysis) of two factors was used as a statistical model for the global evaluation of the phenotypic characteristics of the plants. An F test was carried out on all the measured parameters of all the plants of all the events transformed with the gene of the present invention. The F test was carried out to review an effect of the gene on all transformation events and for the overall effect of the gene, which is also known as the global gene effect. The significance threshold for a true global gene effect was established at a 5% probability level for the F test. A significant F test value points to a gene effect, meaning that it is not just the presence or position of the gene what is causing the differences in phenotype. Parameter measurements related to seeds The mature primary panicles were harvested, counted, bagged, and labeled with a bar code and then dried for 3 days in an oven at a temperature of 37 ° C. The panicles were then shelled and all the seeds were collected and counted. The filled shells were separated from the empty shells using an air blowing device. The empty peels were discarded and the remaining fraction was counted again. The full husks were weighed on an analytical scale. The number of filled seeds was determined by counting the number of full shells that remained after the separation step. The total seed yield was measured by weighing all the full husks harvested from a plant. The total number of seeds per plant was measured by counting the number of peels harvested from a plant. The thousand grain weight (TKW) is extrapolated from the number of filled seeds counted and their total weight. The Harvest index (Hl) in the invention is defined as the ratio between the total yield of seeds and the area above the ground (mm2), multiplied by a factor of 106. The total number of flowers per panicle in accordance with that defined in the present invention is the ratio between the total number of seeds and the number of mature primary panicles. The number of seeds filled, the total yield of seeds (total weight of seeds), the rate of seed filling (which is the number of filled seeds divided by the total number of seeds and multiplied by 100) and the harvest index of Transgenic plants transformed with a nucleic acid encoding YEP16 are shown in Table P. These parameters were significantly increased in the TI generation compared to the corresponding control plants. Average increases in the same parameters were also observed in the T generation: Table P: Results of the number of filled seeds, total weight of seeds, filling rate and harvest index in the Ti generation of transgenic plants transformed with a nucleic acid encoding YEP16.

Examples; Group I hairy kinase and coding nucleic acids Example 28: Gene cloning The gene coding for the hairy type kinase of group I of Oriza sa tiva was amplified by polymerase chain reaction using a cDNA library of seedlings from Arabidopsis thaliana (Invitrogen, Paisley, UK). After reverse transcription of RNA extracted from seedlings, the cDNAs were cloned into pCMV Sport 6.0. The average insert size of the bank was 1.5 kb and the original number of clones was of the order of 1.59 x 107 ufe. He Original titre was determined at 9.6 x 105 cfu / ml after the first amplification of 6 x 10 11 cfu / ml. After plasmid extraction, 200 ng of the quenching was used in a 50 μl PCR mixture. For amplification by polymerase chain reaction, primers prm5797 SEQ ID NO: 179; sense, initial codon in bold, site AttBl in italics: 5 '-ggggacaagtttgtacaaaaaagcaggcttaaacaatgggttcagtaggggttg-3') and prm5798 (SEQ ID NO: 180; reverse, complementary, stop codon in bold letters, site AttB2 in italics: 5'-ggggaccactttgtacaagaaagctgggtgaagctgtctcatactcctgc-3 '), which includes the AttB sites for Gateway recombination. Polymerase chain reaction was performed using Hifi Taq DNA polymerase under standard conditions. A 1328 base pair polymerase chain reaction fragment was amplified and purified using standard methods as well. The first step of the Gateway procedure, the BP reaction, was then carried out, during which the polymerase chain reaction fragment is recombined in vivo with the plasmid pDONR201 to produce, according to the Gateway terminology, an "entry clone". Plasmid pDONR201 was purchased from Invitrogen, as part of the Gateway® technology. Example 29: Construction of Vector The input clone was subsequently used in a reaction of LR with a target vector used for transformation of Oryza sa tiva. This vector contains as functional elements within the borders of T-DNA: a selectable plant marker; a screened marker expression cassette; and a Gateway cassette contemplated for in vivo recombination of LR with the sequence of interest already cloned in the input clone. A GOS2 promoter from rice, for constitutive expression, was upstream of this Gateway cassette (De Peter et al., Plant J. 1992 Nov; 2 (6): 837-44). After the recombination step of RL, the resulting expression vector (FIG. 15) was transformed into strain LBA4044 of Agrobacterium and subsequently into plants of Oriza sativa according to that described in Example 30. The growth of plants was allowed. processed rice which were examined to determine the parameters described in Example 27. Example 30: Rice transformation The rind of mature dry seeds of a variety of rice from Japan was removed. Sterilization was carried out by incubation for 1 minute in 70% ethanol, followed by 30 minutes in 0.2% HgCl2, followed by a 6 x 15 minute wash with sterile distilled water. The sterile seeds were then germinated in a medium containing 2,4-D (callus induction medium). After the incubation in the dark for 4 weeks, embryogenic callus, scutellum derivatives were cut and propagated in the same medium. After two weeks, the calluses were multiplied or propagated by subculture in the same medium for two additional weeks. Embryogenic callus pieces were subcultured in fresh medium 3 days before co-culture (to reinforce cell division activity). Agrobacterium strain LBA4404 containing binary T-DNA vectors was used for co-culture. Agrobacterium was inoculated in AB medium with the appropriate antibiotics and was cultured for 3 days at a temperature of 28 ° C. The bacteria were then harvested and suspended in liquid co-culture medium at a density (OD600) of about 1. The suspension was then transferred to a petri dish and the Callus were submerged in the suspension for 15 minutes. The callus tissues were then dried on filter paper and transferred to a solidified co-culture medium and incubated for 3 days in the dark at a temperature of 25 ° C. The co-cultivated calli were cultured in a medium containing 2 g., 4-D for 4 weeks in darkness at 28 ° C in the presence of an adequate concentration of the selective agent. During this period, islands of resistant calluses of rapid growth were developed. After the transfer of this material to a medium of regeneration and incubation in the light, The embryogenic potential was released and outbreaks developed over the next 4 to 5 weeks. Sprouts were cut from the calluses and incubated for 2 to 3 weeks in a medium containing auxin from which they were transferred to the soil. Hardened shoots were grown under high humidity and short days in a greenhouse. Seeds were then harvested 3 to 5 months after transplanting. The method provided single-locus transformants at a rate of more than 50 (Aldemita and Hodges 199 612-617, 1996, Chan et al., Plant Mol. Biol. 22 (3) 491-506, 1993, Hiei et al., Plant J ., 6 (2) 271-282, 1994). Example 31: Salt Stress Screening Seeds were sown and seedlings were selected by visual marker expression monitoring. Ten days after the planting, the seedlings were transplanted into 12 cm diameter plastic pots, filled with a mixture of wet sand and vermicudite. The pots were soaked with fresh water before transplanting. The seedlings were then transplanted from tissue culture chambers to a greenhouse for growth and harvesting of Pl seeds. The pots were subjected to salt conditions 1 day after transplanting. The pots were watered 4 times a day at 8 am, 12 pm, 4 pm and 9 pm with a salt stress nutrient solution containing 25 mM NaCl and the components listed below.

• NPK nutrient mixture, 20-20-20 Peters professional (Scotts, Marysville, OH, USA) at a concentration of 1 kg / m3. • Magnesium chelate, Chelal Mg (BMS, Bornem, Belgium) at 333.33 ml / m3. • Iron chelate, (CIBA, Bradford, UK) at 21.67 g / m3.

• NaCl 1,425 kg / m3. The salt concentration was monitored weekly and additions were made if necessary. Plants were cultivated under these conditions until the beginning of the filling of the grains. They were then transferred to a different compartment of the greenhouse where they were irrigated daily with fresh water until the seeds were harvested. Growth and yield parameters were recorded in accordance with what was presented in detail in Example 32. Example 32: Evaluation and results Approximately 15-20 independent rice transformants T0 were generated. The primary transformants were transferred from a tissue culture chamber to a greenhouse for growth and harvesting of IT seeds. At least five events were retained for which the IT progeny segregated 3: 1 for the presence / absence of the transgene. For each of these events, approximately 10 Ti seedlings containing the transgene (heterozygous and homozygous) and approximately 10 Ti seedlings that they did not have in the transgene (nullizygotes) were selected by visual marker expression monitoring. Four of the best performing IT events were also evaluated in the T2 generation following the same evaluation procedure as in the case of the IT generation but with more individuals per event. Statistical analysis: Test F An ANOVA (variant analysis) of two factors was used as a statistical model for the global evaluation of the phenotypic characteristics of the plants. An F test was carried out on all the measured parameters of all the plants of all the events transformed with the gene of the present invention. The F test was carried out to review an effect of the gene on the transformation events and for the overall effect of the gene, which is also known as the global gene effect. The significance threshold for a true global gene effect was established at a 5% probability level. A significant F test value points to a gene effect, which means that it is not just the presence or position of the gene that is causing the phenotype differences. 32.1 Measurements of seeds-related parameters Mature primary panicles were harvested, bagged, labeled with a bar code and then dried for 3 days in the oven at a temperature of 37 ° C. they were then shelled and all the seeds were collected and counted. The filled shells were separated from the empty shells using an air blowing device. The empty shells were discarded and the remaining fraction was counted again. The filled husks were weighed on an analytical scale. The total seed yield was measured by weighing all the full husks harvested from a plant. The Harvest Index in the present invention is defined as the ratio between the total yield of seeds and the area above ground (mm2), multiplied by a factor of 106. The Table of results below shows the P values from the test F for TI and T2 evaluations. The percentage difference between the transgenics and the corresponding nullizygotes (or plants without the transgene) is also shown. For example, in the case of the total weight of seeds in the TI generation, two events were positive for total weight of seeds (that is, they showed an increase in the total weight of seeds (of> 54%, with a P value of of the F test of <0.1938) in comparison with the seed weight of corresponding nullizygous plants under salt stress conditions). In generation T2, one event was positive for the total seed weight (ie, it showed an increase in total seed weight (of 65%, with a P value from F test of 0.0252) compared to the seed weight of corresponding nullizygous plants under salt stress conditions). Table Q: Transgenic hairy type kinase plants of Ti and T2 generation and corresponding non-transgenic plants under salt stress Transformation of corn, wheat, soybean, canola, alfalfa, with sequences useful in the methods of the invention Corn transformation The transformation of corn (Zea mays) is carried out with a modification of the method described by Ishida et al. (1996) Nature Biotech 14 (6): 745-50. The transformation depends on the genotype in the maize and only specific genotypes lend themselves to transformation and regeneration. The inbred line A188 (University of Minnesota) of hybrids with A188 as ancestor are good sources of donor material for transformation, but these genotypes can be used successfully as well. Cobs are harvested from maize plants approximately 11 days after the pollination (DAP) when the length of the immature embryo is approximately 1 to 1.2 mm. Mature embryos are co-cultured with Agrobacterium tumefaciens that contains the expression vector, and transgenic plants are recovered through organogenesis. The reported embryos are cultured in callus induction medium, then corn regeneration medium, which contains the selection agent (for example imidazolinone but several selection markers can be used). The Petri dishes are incubated in the light at a temperature of 25 ° C for 2-3 weeks, or until the development of shoots. The green shoots are transferred from each embryo to a medium of corn root development and are incubated at a temperature of 25 ° C for 2-3 weeks, or until the development of the roots. The Ingrained shoots are transplanted to the soil in the greenhouse. TI seeds are produced from plants that exhibit tolerance to the selection agent and that contain a single copy of the T-DNA insert. Transformation of wheat The transformation of wheat was carried out with the method described by Ishida et al. (1996) Nature Biotech 14 (6): 745-50. The Bobwithe species (available at CIMMYT, Mexico) is commonly used in transformation. Immature embryos are co-cultivated with Agrobacterium tumefaciens that contains the expression vector, and transgenic plants are recovered through organogenesis. After incubation with Agrobacterium, the embryos grow in vi tro in callus induction medium, then regeneration medium, which contains the selection agent (for example, imidazolinone but several selection markers can be used). The Petri dishes are incubated in the light at a temperature of 25 ° C for 2-3 weeks, or until the development of shoots. The green shoots are transferred from each embryo to a medium for the development of roots and are incubated at 25 ° C for 2-3 weeks, or until the development of the roots. The rooted shoots are transplanted to the soil in the greenhouse. TI seeds are produced from plants that exhibit tolerance to the selection agent and that contain a single copy of the T-DNA insert.

Soy transformation Soybeans are processed in accordance with a modification of the method described in US Pat. No. 5,164,310 of Texas A &M. Several commercial varieties of soybean lend themselves to transformation with this method. The Jack variety (available at the Illinois Seed Foundation) is commonly used for transformation. Soybeans are sterilized for sowing in vi tro. The hypocotyl, the radiculum and a cotyledon are cut from young 7-day-old seedlings. The epicotyl and the remaining cotyledon are further cultured to develop axillary nodes. These axillary nodes are cut and incubated with Agrobacterium tumefaciens which contains the expression vector. After the co-culture treatment, the explants are washed and transferred to selection medium. The regenerated shoots are cut and placed in a shoot elongation medium. Sprouts no larger than 1 cm are placed in the middle for the development of roots until the development of the roots. The shoots with roots are transplanted to the soil in the greenhouse. TI seeds are produced from plants that exhibit tolerance to the selection agent and that contain a single copy of the T-DNA insert. Transformation of rapeseed / canola Cotyledonary and hypocotyl petioles of 5-6-day-old seedlings are used as explant for cultivation tissue and transformed according to Babic et al. (1998, Plant Cell Rep 17: 183-188). The commercial variety Westar (Agriculture Canada) is the standard variety used for transformation, but other varieties can also be used. Cannula seeds are sterilized on the surface for sowing in vi tro. Plants of cotyledon petioles with the enclosed cotyledon are removed from the in vitro plantlets, and inoculated with Agrobacterium (which contains the expression vector) by submerging the cut end of the petiole explant in the bacterial suspension. The explants are then cultured for 2 days in an MSBAP-3 medium containing 3 mg / ml of BAP, 3% sucrose, 0.7% Phytagar at a temperature of 23 ° C, 16 hours of light. After 2 days of co-culture with Agrobacterium, the petiole explant is transferred to an MSBAP medium containing 3 mg / ml of BAP, cefotaxime, carbenicillin, or timentin (300 mg / l) for 7 days, and then cultured in MSBAP-3 medium with cefotaxime, carbenicillin, or timentina and selection agent until regeneration of shoots. When the shoots are 5-10 mm long, they are cut and transferred to a shoot elongation medium (MSBAP-0.5, which contains 0.5 mg / l BAP). Sprouts of approximately 2 cm in length are transferred to the root development medium (MS0) for root induction. The shoots with roots are transplanted to the ground in the greenhouse. Ti seeds are produced from plants that exhibit tolerance to the selection agent and that contain a single copy of the T-DNA insert. Transformation of alfalfa A clone of alfalfa regeneration (Medicago sa tiva) is transformed using the method of (McKersie et al., 1999 Plant Physiol 119: 839-847). The regeneration and transformation of alpha is dependent on the genotype and therefore a regeneration plant is required. Methods to obtain regeneration plants have been described. For example, they can be selected from the Rangelander variety (Agriculture Canada) or any other commercial variety of alfalfa as described by Brown DCW and A Atanassov (1985. Plant Cell Tissue Organ Culture 4: 111-112). Alternatively, the RA3 variety ((University of Wisconsin) has been selected for use in tissue culture (Waiker et al., 1978 Am J Bot 65: 654-659). Petiole explanations are co-cultured with overnight culture. Agrobacterium tumefaciens C58C1 pMP90 (McKersie et al., 1999 Plant Physiol 119: 839-847) or LBA4404 containing the expression vector Explants are co-cultured for 3 days in the dark in SH induction medium containing 288 mg / L of Pro, 53 mg / L of thioproline, 4.35 g / L of K2S04, and 100 μm of acetosyrininone The explants are washed in medium Murashige-Skoog (Murashige and Skoog, 1962) of semiconcentration and plated on the same SH induction medium without acetosyrininone but with a suitable selection agent and an appropriate antibiotic to inhibit the growth of Agrobacterium. After several weeks, somatic embryos are transferred to a B0Í2Y development medium that does not contain growth regulators, does not contain antibiotics and 50 g / L of sucrose. Somatic embryos are subsequently germinated in a semi-concentrated Murashige-Skoog medium. Ingrained seedlings were transferred to pots and grown in a greenhouse. TI seeds are produced from plants that exhibit tolerance to the selection agent and that contain a single copy of the T-DNA insert.

Claims (114)

1. CLAIMS 1. A method for increasing the yield of plants compared to corresponding wild-type plants, which comprises modulating the expression in a plant of a Hox5 polypeptide of homeodomain leukin lock (HDZip) class I or homologue thereof , and optionally the selection of plants that have an increased yield, wherein said hox5 HDZip class I polypeptide or homologue thereof comprises from N-terminal to C-terminal: (i) an acidic cadre; and (ii) a class I homeodomain; and (iii) a leucine closure with more than 5 heptates.
2. 2. A method according to claim 1, wherein said hox5 polypeptide of HDZip class I or homolog thereof thereof further comprises one or both of the following: (i) a Trp tail; and (ii) an amino acid motif of RPFF, wherein R is Arg, P is Pro and F is Phe, and within this motif, allowing one or several conservative changes at any position, and / or one or two non-conservative changes in any position.
3. 3. A method according to claim 1 or 2, wherein said modulated expression is effected by introducing a genetic modification preferably at the locus of a gene encoding a hox5 polypeptide of HDZip class I or homologue thereof.
4. 4. A method according to claim 3, in where said genetic modification is effected by one of the following: activation of T-DNA, TILLING, site-directed mutagenesis or directed evolution.
5. 5. A method for increasing the yield of plants compared to wild-type plants comprising the introduction and expression in a plant of a hox5 nucleic acid of HDZip class I or a variant thereof.
6. 6. A method according to claim 5, wherein said variant is a portion of a hox5 nucleic acid of HDZip class I, said portion encoding a polypeptide comprising from N-terminal to C-terminal: (i) an acidic picture; and (ii) a class I homeodomain; and (iii) a leucine closure with more than 5 heptates.
7. 7. A method according to claim 5, wherein said variant is a sequence capable of hybridizing with a hox5 nucleic acid of HDZip class I, said hybridization sequence encoding a polypeptide comprising from N-terminal to C-terminal: (i) an acidic picture; and (ii) a class I homeodomain; and (iii) a leucine closure with more than 5 heptates.
8. 8. A method according to claims 5 to 7, wherein said hox5 nucleic acid of HDZip class I or variant thereof is expressed in a plant.
9. 9. A method according to any of claims 5 to 8, wherein said nucleic acid hox5 of Class I HDZip or variant thereof is of vegetable origin, preferably of a monocotyledonous plant, with additional preference of the Poaceae family, with a greater preference of the genus Oryza, especially of Oryza sa tiva.
10. 10. A method according to any of claims 5 to 9, wherein said variant encodes an ortholog or paralog of the hox5 protein of HDZip of class I of SEQ ID NO: 2.
11. 11. A method of compliance with any of the claims 5 to 10, wherein said hox5 nucleic acid of HDZip class I or variant thereof is operably linked to a constitutive promoter.
12. 12. A method according to claim 11, wherein said constitutive promoter is a GOS2 promoter, more preferably, the constitutive promoter is a rice GOS2 promoter, further preferably the constitutive promoter is represented by a nucleic acid sequence substantially similar to SEQ ID NO: 33 or SEQ ID NO: 178, more preferably the constitutive promoter is in accordance with that represented by SEQ ID NO: 33 or SEQ ID NO: 178.
13. 13. A method according to any of the claims 1 to 12, wherein said increased yield is selected from one or more of the following: increased number of filled seeds, total yield of increased seed, increased number of flowers per panicle, increased seed filling rate, increased harvest index (Hl), increased thousand kernel weight (TKW), increased root length or increased root diameter, all in comparison with corresponding wild type plants.
14. 14. A method according to any of claims 1 to 13, wherein said increased yield occurs under abiotic stress.
15. 15. A method according to claim 14, wherein said abiotic stress is an osmotic stress, selected from one or more of the following: water stress, salt stress, oxidative stress and ionic stress, preferably wherein said stress Water is stress of drought.
16. 16. A method according to claim 14 or 15, wherein said abiotic stress tolerance is manifested in the form of an increased yield selected from one or more of the following: increased number of filled seeds, total increased seed yield, number increased of flowers per panicle, increased rate of seed filling, increased Hl, increased TKW, increased root length or increased root diameter, all these compared to wild type plants.
17. 17. A method according to claims 13 to 16, wherein said increased yield comprises an increased greenness index.
18. 18. Plant, plant part, or plant cell that can be obtained through a method according to any of claims 1 to 17.
19. 19. Use of a construct comprising: (i) a hox5 nucleic acid of HDZip of class I or variant thereof; (ü) one or more control sequences capable of promoting the expression of the nucleic acid sequence of (i); and optionally (iii) a transcription termination sequence, in a method according to any of claims 5 to 17.
20. 20. The construct according to claim 19, wherein said control sequence is a constitutive promoter.
21. 21. The construct according to claim 20, wherein said constitutive promoter is a GOS2 promoter, preferably the rice GOS2 promoter, further preferably the constitutive promoter is represented by a nucleic acid sequence substantially similar to SEQ ID NO: 33 or SEQ ID NO: 178, more preferably the constitutive promoter is in accordance with that represented by SEQ ID NO: 33 or SEQ ID NO: 178.
22. 22. Plant, plant part, or plant cell transformed with a construct comprising a hox5 nucleic acid of HDZip class I or a variant thereof under the control of a GOS2 promoter.
23. 23. A method for the production of a transgenic plant that has an increased yield as compared to a corresponding wild-type plant, said method comprising: (i) introducing and expressing in a plant or plant cell a hox5 nucleic acid of HDZip class I or variant thereof; (ii) (ii) cultivate the plant cell under conditions that promote the growth and development of the plant.
24. 24. A method according to claim 23, wherein said increased yield occurs under increased abiotic stress.
25. 25. Transgenic plant having an increased yield as compared to a corresponding wild-type plant, said increased growth is the result of a hox5 nucleic acid of HDZip class I or a variant thereof introduced in said plant.
26. 26. A transgenic plant according to claim 18, 22 or 25, wherein said plant is a monocotyledonous plant such as, for example, sugar cane, or where The plant is a cereal, such as rice, corn, wheat, barley, millet, rye, oats or sorghum.
27. 27. Harverable parts of a plant according to any of claims 18, 22, 25 or 26.
28. 28. Harverable parts of a plant according to claim 27, wherein said harvestable parts are seeds.
29. 29. Products derived from a plant according to claim 26 and / or from harvestable parts of a plant according to claims 27 or 28.
30. 30. The use of nucleic acid / hox5 gene of HDZip class I or variant thereof , or the use of a hox5 polypeptide of HDZip class I or homologue thereof, in the increase of yield of plants compared to corresponding wild-type plants.
31. 31. The use according to claim 30, wherein said increased yield is selected from one or more of the following: increased number of filled seeds, total yield of seeds increased, increased number of flowers per panicle, rate of seed filling increased, increased HL, increased TKW, increased root length or increased root diameter, all of the above compared to wild type plants.
32. 32. Use according to claim 30 or 31, wherein said increased yield occurs under increased abiotic stress.
33. 33. The use according to claim 32, wherein said increased yield comprises increased greenness index.
34. 34. The use of a nucleic acid / hox5 gene of HDZip class I or variant thereof, or use of a hox5 polypeptide of HDZip class I or homolog thereof, as a molecular marker.
35. 35. A method for improving the growth characteristics of plants compared to corresponding wild-type plants, comprising modulating the expression in a plant of a nucleic acid encoding a NRT polypeptide or a homologue thereof, and optionally selecting plants which have improved growth characteristics.
36. 36. A method according to claim 35, wherein said modulated expression is effected by introducing a genetic modification preferably at the locus of a gene in accordance with a NRT polypeptide or a homologue thereof.
37. 37. A method according to claim 36, wherein said genetic modification is effected by one of the following: activation of T-DNA, TILLING, site-directed mutagenesis, homologous recombination or directed evolution.
38. 38. A method for improving growth characteristics compared to corresponding wild type plants, comprising the introduction and expression in a plant of a NRP nucleic acid or a variant thereof.
39. 39. A method according to claim 38, wherein said nucleic acid encodes a homolog of the NRT protein of SEQ ID NO: 53, preferably said nucleic acid encodes an ortholog or a paralog of the NRT protein of SEQ ID NO: 53
40. 40. A method according to claim 38, wherein said variant is a portion of a NRT nucleic acid or a sequence capable of hybridizing with NRT nucleic acid, said portion or hybridization sequence encoding a polypeptide comprising: (i) an MFS_1 domain, (ii) a transmembrane domain located C-terminally of the MFS_1 domain and preferably also having an NRT activity.
41. 41. A method according to any of claims 38 to 40, wherein said NRT nucleic acid or variant thereof is over expressed in a plant.
42. 42. A method according to any of claims 38 to 41, wherein said nucleic acid NRT or variant thereof is of plant origin, preferably of a monocotyledonous plant, more preferably of the Poaceae family, more preferably the nucleic acid. is from Oryza sa tiva.
43. 43. A method according to any of claims 38 to 42, wherein said nucleic acid NRT or variant thereof is operably linked to a constitutive promoter.
44. 44. A method according to claim 43, wherein said constitutive promoter is a GOS2 promoter.
45. 45. A method according to any of claims 35 to 44, wherein said improved growth characteristic is increased yield.
46. 46. A method according to claim 45, wherein said increased yield is increased yield of seeds.
47. 47. A method according to claim 46, wherein said increased yield of seeds is selected from: increased total weight of seeds, total number of seeds increased, number of seeds increased, number of flowers increased per panicle or harvest index increased.
48. 48. Plant or plant cell obtainable by a method according to any of claims 35 to 47.
49. 49. Construct comprising: (i) a NRT nucleic acid or a variant thereof; (ii) one or more control sequences capable of boost the expression of the nucleic acid sequence of (i); and optionally (iii) a transcription termination sequence.
50. 50. Construct according to claim 49, wherein said control sequence is a constitutive promoter.
51. 51. Conformity construct according to claim 50, wherein said constitutive promoter is a GOS2 promoter.
52. 52. Conformity construct according to claim 51, wherein said GOS2 promoter is in accordance with that represented by nucleotides 1 to 2193 of SEQ ID NO: 56.
53. 53. Plant or plant cell transformed with a construct in accordance with any of claims 49 to 52.
54. 54. A method for the production of a transgenic plant having an increased yield as compared to corresponding wild-type plants, said method comprising: (i) introduction and expression in a plant or plant cell of a NRT nucleic acid or variant thereof; (ii) cultivation of the plant cell under conditions that promote the growth of the plant and its development.
55. 55. Transgenic plant or plant cell having improved growth characteristics resulting from a NRT nucleic acid or a variant thereof introduced into said plant.
56. 56. A transgenic plant or plant cell according to claim 48, 53 or 55, wherein said plant is a monocotyledonous plant, such as, for example, sugar cane, or wherein the plant is a cereal, such as, for example, rice, corn , wheat, barley, millet, rye, oats or sorghum, or wherein said cell of transgenic plant is derived from a monocotyledonous plant, such as sugarcane or where the plant is a cereal, such as rice, corn, wheat, barley, millet, rye, oats or sorghum.
57. 57. Harverable parts of a plant according to any of claims 48, 53, 55 or 56.
58. 58. Harverable parts of a plant according to claim 57, wherein said harvestable parts are seeds.
59. 59. Products directly derived from a plant according to claim 56 and / or harvestable parts of a plant according to claims 57 or 58.
60. 60. The use of nucleic acid / NRT gene or variant thereof, or use of a NRT polypeptide or a homologue thereof, in improving the growth characteristics of plants, preferably in an improvement of yield, especially of seed yield, in comparison with corresponding plants of wild type.
61. 61. The use according to claim 60, wherein said seed yield is one or more of the following: increased total seed weight, increased total number of seeds, increased number of filled seeds, increased number of flowers per panicle or increased harvest index.
62. 62. Use of a nucleic acid / NRT gene or variant thereof, or use of a NRT polypeptide or a homologue thereof, as a molecular marker.
63. 63. A method for improving the yield of plants compared to corresponding wild type plants, which comprises modulating the expression in a plant of a nucleic acid encoding a YEP16 polypeptide or a homolog thereof, wherein said YEP16 polypeptide or a counterpart thereof comprises, in increasing order of preference, a sequence identity of at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% with the amino acid sequence of SEQ ID NO: 128.
64. 64. A method according to claim 63, wherein said modulated expression is an increased expression.
65. 65. A method according to claim 63 or 64, wherein said modulated expression is effected by means of the introduction of a genetic modification preferably at the ungen locus encoding a YEP16 polypeptide or a homologue thereof.
66. 66. A method according to claim 65, wherein said genetic modification is effected by one of the following: activation of T-DNA, TILLING, site-directed mutagenesis, or directed evolution.
67. 67. A method to improve the performance of plants compared to corresponding wild-type plants, which comprises the introduction and expression in a plant of a nucleic acid encoding a YEP16 polypeptide or a homologue thereof, wherein said YEP16 polypeptide or a homologue thereof comprises, in increasing order of preference, a sequence identity of less 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% with the amino acid sequence of SEQ ID NO: 128.
68. 68. A method according to any of claims 63 to 67, wherein said YEP16 polypeptide or homologue thereof is targeted to a plastid.
69. 69. A method according to claim 68, wherein said plastid is a chloroplast.
70. 70. A method according to any of claims 67 to 69, wherein said nucleic acid encoding a YEP16 polypeptide or a homolog thereof is a nucleic acid sequence capable of hybridizing under reduced stringency conditions to a nucleic acid in accordance with that represented by SEQ ID NO: 127 or SEQ ID NO: 129.
71. 71. A method according to any of claims 67 to 70, wherein said nucleic acid encoding a YEP16 polypeptide or a homologue thereof is a nucleic acid sequence having, in increasing order of preference, at least 100, 125, 150. 175, 200, 225, 250, 275, 300, 325, 350, 375, 400 , 425, 450, 475, 500, 525, 550, 575 consecutive nucleotides of a nucleic acid in accordance with that represented by SEQ ID NO: 127 or SEQ ID NO: 129.
72. 72. A method according to any of claims 67 to 71, wherein said nucleic acid encoding a YEP16 polypeptide or a homologue thereof encodes an ortholog or paralog of the YEP16 polypeptide of SEQ ID NO: 128 or SEQ ID NO: 130.
73. 73. A method according to claim 67 a 72, wherein said nucleic acid encoding a YEP16 polypeptide or a homolog thereof is over expressed in a plant.
74. 74. A method according to claim 67 a 73, wherein said nucleic acid encoding a YEP16 polypeptide or a homologue thereof is of plant origin, preferably of a dicotyledonous species, preferably of the Brassicaceae family, with a greater preference for Arabidopsis thaliana.
75. 75. A method according to any of claims 67 to 74, wherein said nucleic acid encoding a YEP16 polypeptide or a homologue thereof is operably linked to a seed-specific promoter.
76. 76. A method according to claim 75, wherein said seed-specific promoter is an oleosin promoter, preferably the rice oleosin promoter, preferably further in accordance with that represented by SEQ ID NO: 143.
77. 77. A method of according to claims 63 to 76, wherein said improved yield is the improved yield of seeds compared to corresponding wild-type plants.
78. 78. A method according to claim 77, wherein said improved seed yield is selected from one or more of the following: increased seed weight, increased number of filled seeds, increased rate of seed filling, and harvest index increased.
79. 79. Plant or plant cell obtainable by the method according to any of claims 63 to 78.
80. 80. Construct comprising: (i) a nucleic acid encoding a YEP16 polypeptide or a homologue thereof, wherein said polypeptide YEP16 or a homologue thereof comprises in increasing order of preference a sequence identity of at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% with the amino acid sequence of SEQ ID NO: 128; (ii) one or more control sequences capable of driving the expression of the nucleic acid sequence of (i); and optionally (iii) a transcription termination sequence.
81. 81. A construct according to claim 80, wherein said control sequence is a seed-specific promoter.
82. 82. A construct according to claim 81, wherein said seed-specific promoter is an oleosin promoter, preferably the rice oleosin promoter.
83. 83. Plant, part of plant, or plant cell transformed with a construct according to any of claims 80 to 82.
84. 84. A method for the production of a transgenic plant that has an improved yield as compared to a plant of type corresponding wild type, said method comprises: (i) introducing and expressing in a plant or plant cell a nucleic acid encoding a YEP16 polypeptide or a homologue thereof, wherein said YEP16 polypeptide or a homologue thereof comprises, in increasing order of preference, a sequence identity of at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% with the amino acid sequence of SEQ ID NO: 128 , (ii) cultivate the plant cell under conditions that promote the growth of the plant and its development.
85. 85. A transgenic plant having an improved yield as compared to a corresponding wild-type plant resulting from a nucleic acid encoding a YEP16 polypeptide or a homologue thereof, wherein said YEP16 polypeptide or a homologue thereof comprises in increasing order of preference a sequence identity of at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% with the amino acid sequence of SEQ ID NO: 128.
86. 86. Transgenic plant according to claim 79, 83 or 85, wherein said plant is a monocotyledonous plant, such as sugarcane, or wherein the plant is a cereal, such as rice, corn, wheat, barley, millet, rye, oats or sorghum.
87. 87. Harverable parts of a plant according to any of claims 79, 83, 85 or 86.
88. 88. Harverable parts of a plant according to claim 87, wherein said harvestable parts are seeds.
89. 89. Products directly derived from a plant according to claim 86 and / or harvestable parts of a plant according to claims 87 or 88.
90. 90. The use of a nucleic acid encoding a YEP16 polypeptide or a homologue thereof. , wherein said YEP16 polypeptide or a homologue thereof comprises, in increasing order of preference, a sequence identity of at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65% , 70%, 75%, 80%, 85%, 90%, 95% with the amino acid sequence of SEQ ID NO: 128 in plant yield improvement compared to the corresponding wild-type plants.
91. 91. The use according to claim 90, wherein said improved yield is selected from one or more of the following: increased seed weight, increased number of filled seeds, increased rate of filling and increased rate of harvest.
92. 92. The use of a nucleic acid encoding a YEP16 polypeptide or a homologue thereof as a molecular marker, wherein said YEP16 polypeptide or a homologue thereof comprises, in increasing order of preference, a sequence identity of at least 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85 %, 90%, 95% with the amino acid sequence of SEQ ID NO: 128.
93. 93. A method for improving tolerance to abiotic stress in plants, comprising increasing the activity in a plant of a hairy type kinase of group I or a homologue thereof, said hairy type kinase of group I is a kinase having: (i) a sequence identity of at least 77% with the amino acid sequence represented by SEQ ID NO: 147; and (ii) motif I: R / H / V / N / Q E / G LK G / N and motif II: K Q / N CXXX G / A / S, where X can be any amino acid.
94. 94. A method according to claim 93, wherein said increased activity is effected by the introduction of a genetic modification, preferably at the locus of a gene encoding a group I hairy type kinase, said locus is a genomic region which includes the gene of interest and 10 kb upstream or downstream of the coding region.
95. 95. A method according to claim 94, wherein said genetic modification is effected by any of the following: site-directed mutagenesis, homologous recombination, TILLING, activation of T-DNA and by introduction and expression in a plant of an acid nucleic acid encoding a hairy type of group I or its homologue.
96. 96. A method for improving tolerance to abiotic stress in plants, comprising the introduction and expression in a plant of a nucleic acid / gene encoding a Group I hairy kinase or variant thereof.
97. 97. A method according to claim 96, wherein said variant is a portion of a nucleic acid / gene encoding a Group I hairy kinase and / or a nucleic acid capable of hybridizing to a nucleic acid / gene that encodes a Group I hairy kinase, said portion or hybridization sequence having a length of at least 1,200 nucleotides, and said portion or hybridization sequence encoding a polypeptide having: (i) a sequence identity of at least 77% with the amino acid sequence represented by SEQ ID NO: 147; and (ii) motif I: R / H / V / N / Q E / G LK G / N and motif II: K Q / N CXXX G / A / S, where X can be any amino acid.
98. 98. A method according to claim 96 or 97, wherein said nucleic acid / gene encoding a Group I hairy kinase or variant thereof is over expressed in a plant.
99. 99. A method according to any of claims 96 or 98, wherein said nucleic acid / gene encoding a hairy type kinase of Group I or variant thereof is of vegetable origin, preferably of a monocotyledonous plant, with additional preference of the family Poaceae, with greater preference of the genus Oryza, and very especially of Oriza sa tiva.
100. 100. A method according to any of claims 96 to 99, wherein said nucleic acid / gene encoding a Group I hairy type kinase or variant thereof is operably linked to a constitutive promoter, preferably a GOS2.0 promoter.
101. 101. A method according to any of claims 93 to 100, wherein said abiotic stress is one or several of the following: water stress, anaerobic stress, salt stress, temperature stress, chemical toxicity stress and oxidative stress .
102. 102. A method according to any of claims 93 to 101, wherein said abiotic stress is an osmotic stress selected from salt stress, water stress, oxidative stress, ionic stress.
103. 103. Plant or plant cell that can be obtained through a method according to any of claims 93 to 102, wherein the plant or plant cell has an increased activity of a Group I hairy kinase and / or increased expression of a nucleic acid encoding a Group I hairy kinase.
104. 104. Construct comprising: (i) a nucleic acid that modifies a hairy type kinase of Group I or variant thereof; (ii) one or more control sequences capable of driving the expression of the nucleic acid sequence of (i); and optionally (iii) a transcription termination sequence.
105. 105. The construct according to claim 104, wherein said control sequence comprises a constitutive promoter, preferably the GOS2 promoter, such as for example the rice GOS2 promoter.
106. 106. Plant or plant cell transformed with a construct according to claim 104 or 105.
107. 107. A method for the production of transgenic plants having an improved tolerance to abiotic stress, said method comprises: (i) introduction into a plant or plant cell of a nucleic acid encoding a Group I hairy kinase or variant thereof; (ii) cultivation of the plant cell under conditions that promote the growth of the plant and its development.
108. 108. A method according to claim 107, wherein said abiotic stress is an osmotic stress, selected from salt stress, water stress, stress oxidant, ionic stress.
109. 109. A transgenic plant having an improved tolerance to abiotic stress in comparison with corresponding wild-type plants, said transgenic plant having an increased activity of a Group I hairy kinase and / or an increased expression of a nucleic acid encoding a Group I hairy kinase.
110. 110. Transgenic plant according to any of claims 103, 106 and 109, said transgenic plant is a harvest plant, for example soybean, sunflower, canola, alfalfa, rapeseed, cotton, tomato, potato or tobacco, preferably further this plant is a monocotyledonous plant such as sugarcane, more preferably a cereal, such as rice, corn, wheat, barley, millet, rye, sorghum or oats.
111. 111. Harverable parts, including seeds, of transgenic plant according to any of claims 103, 106, 109 to 110.
112. 112. The use of a nucleic acid encoding a hairy type kinase of Group I or variant thereof or use of a Group I hairy kinase or its homologue in the increase of the tolerance of the plant to abiotic stress.
113. 113. The use according to claim 112, wherein said abiotic stress is an osmotic stress, selected between salt stress, water stress, oxidant stress, ionic stress.
114. 114. The use of a nucleic acid encoding a Group I hairy kinase or variant thereof or the use of a Group I hairy kinase or homologue thereof as a molecular marker. SUMMARY OF THE INVENTION The present invention relates, in general terms, to the field of molecular biology and relates to a method for improving the growth characteristics of plants compared to corresponding wild-type plants. More specifically, the present invention relates to a method for improving the growth characteristics of plants, said method comprising modulating the expression in a plant of a nucleic acid encoding a class I homeodomain leucine closure polypeptide hox5. (HDZip) or a homolog thereof; or it comprises the modulation of the expression in a plant of a nucleic acid encoding a nitrate carrier protein (NRT) or a homologue thereof; or it comprises the modulation of the expression in a plant of a nucleic acid encoding a polypeptide designated Performance Enhancing Protein 16 (known as YEP 16), or comprising the modulation of the expression in a plant of a glycogen synthase kinase of group I (hairy type kinase of group I) or a homologue thereof. The present invention also relates to plants having a modulated expression of a nucleic acid encoding a Hox5 polypeptide of homeodomain leukin lock (HDZip) class I or a homologue thereof; or that it has a modulated expression of a nucleic acid that encodes a nitrate transporter protein (NRT) or a counterpart thereof; or else having a modulated expression of a nucleic acid encoding a polypeptide designated Protein Enhancement Protein 16 (hereinafter referred to as YEP 16); or that it has a modulated expression of a group glycogen synthase kinase I (hairy type kinase of group I) or a homologue thereof, said plants have improved growth characteristics compared to corresponding wild type plants. The invention also provides constructs useful in the methods of the invention.