Plants having modified growth characteristics and a method for making the same

Abstract

The present invention relates generally to the field of molecular biology and concerns a method for improving various economically important growth characteristics in plants. More specifically, the present invention concerns inter alia a method for modifying growth characteristics in plants by modulating expression in a plant of a nucleic acid encoding a HUB1 (Histone Monoubiquitination 1) polypeptide or encoding another protein useful in the methods of the present invention. The modified growth characteristics comprise a modification of light regulated phenotypes, such as modified circadian clock and/or circadian clock responses, or modified plant architecture.

1 . A method for improving growth characteristics in a plant relative to a control plant, comprising introducing and expressing in a plant a nucleic acid encoding a HUB1 polypeptide operably linked to a medium strength constitutive promoter, wherein the HUB1 polypeptide comprises a RING domain of a C3HC4 type. 
     
     
         2 . The method of  claim 1 , wherein the nucleic acid encodes any one of the proteins listed in Table A or is a portion of such a nucleic acid, or a nucleic acid capable of hybridizing with such a nucleic acid. 
     
     
         3 . The method of  claim 1 , wherein the improved growth characteristics comprise one or more of increased germination vigour, increased early vigour, increased yield, increased biomass, and/or increased seed yield relative to a control plant. 
     
     
         4 . The method of  claim 1 , wherein the improved growth characteristics are obtained under non-stress conditions. 
     
     
         5 . The method of  claim 1 , wherein the improved growth characteristics are obtained under conditions of drought stress, salt stress, or nitrogen deficiency. 
     
     
         6 . The method of  claim 1 , wherein the medium strength constitutive promoter is a HMGP promoter or a HMGP promoter from rice. 
     
     
         7 . A construct comprising:
 (i) a nucleic acid encoding a HUB1 polypeptide as defined in  claim 1 ;   (ii) one or more heterologous medium strength control sequences capable of driving expression of the nucleic acid of (i); and optionally   (iii) a transcription termination sequence.   
     
     
         8 . The construct of  claim 7 , wherein one of the medium strength control sequences is a constitutive promoter, a HMGP promoter, or a HMGP promoter from rice. 
     
     
         9 . A method for making a plant having one or more of increased germination vigour, increased early vigour, and increased yield, relative to a control plant, comprising transforming a plant, plant cell or plant part with the construct of  claim 7 . 
     
     
         10 . A plant, plant cell or plant part comprising the construct of  claim 7 . 
     
     
         11 . A method for the production of a transgenic plant having improved growth properties, increased germination vigour, increased early vigour, and/or increased yield relative to a control plant, comprising:
 (i) introducing and expressing in a plant or plant cell a nucleic acid encoding a HUB1 polypeptide as defined in  claim 1 ;   (ii) cultivating the plant or plant cell under conditions promoting plant growth and development; and   (iii) selecting for a plant having improved growth properties, increased germination vigour, increased early vigour, and/or increased yield relative to a control plant.   
     
     
         12 . A transgenic plant obtained by the method of  claim 11 , or a plant cell, plant part, seed, or progeny of said plant, wherein said plant, plant cell, plant part, seed, or progeny comprises a recombinant nucleic acid encoding said HUB1 polypeptide. 
     
     
         13 . A transgenic plant having improved growth properties, increased germination vigour, increased early vigour, and/or increased yield relative to a control plant, resulting from modulated expression of a nucleic acid encoding a HUB1 polypeptide as defined in  claim 1 , or a transgenic plant cell derived from said transgenic plant. 
     
     
         14 . The transgenic plant of  claim 13 , or a transgenic plant cell derived therefrom, wherein said plant is a crop plant, a monocot, or a cereal, or wherein said plant is rice, maize, wheat, barley, millet, rye, triticale, sorghum, emmer, spelt, secale, einkorn, teff, milo or oats. 
     
     
         15 . Harvestable parts of the transgenic plant of  claim 13 , wherein the harvestable parts are shoot biomass and/or seeds and comprise a recombinant nucleic acid encoding said HUB1 polypeptide. 
     
     
         16 . A product derived from the transgenic plant of  claim 13  and/or from harvestable parts of said plant, wherein said product comprises a recombinant nucleic acid encoding said HUB1 polypeptide. 
     
     
         17 . A method for modifying a light regulated phenotype in a plant, comprising expression in a plant of a nucleic acid encoding a HUB1 polypeptide. 
     
     
         18 . A method for modifying plant growth characteristics relative to a control plant, comprising modulating expression in a plant of a nucleic acid encoding any of the proteins listed in Tables G to K, or an orthologue thereof, wherein the plant growth characteristics comprise increased yield and/or increased stress resistance. 
     
     
         19 . The method of  claim 18 , wherein the modified growth characteristics comprise increased yield, increased stress resistance, and/or modified architecture. 
     
     
         20 . The method of  claim 19 , wherein the increased yield comprises increased biomass and/or increased seed yield, or wherein the increased stress resistance is one or more of increased drought stress resistance, increased salt stress resistance, and/or improved growth under conditions of nutrient deficiency.