Mutation of the ear motif of class ii hd-zip polypeptides

Abstract

The application describes producing polynucleotide variants of the AtHB 17 clade members and introducing the mutant variants into plants to improve plant traits. The mutant polynucleotides encode polypeptides that comprise mutations in the EAR motifs.

What is claimed is: 
     
         1 . A transgenic plant having an improved trait relative to a first control plant of the same species wherein
 the transgenic plant comprises a recombinant polynucleotide encoding a polypeptide that comprises:   a mutant EAR motif of X 1 -X 2 -X 3 -X 4 -X 5  (set forth in SEQ ID NO: 1), where X 1  and X 3  are any amino acid other than leucine, isoleucine or valine; X 2  and X 4  are any amino acid; and X 5  is isoleucine, leucine or methionine;   a homeodomain that shares an amino acid percentage identity to the homeodomain of any of SEQ ID NO: 2-20; and   a homeobox-associated leucine zipper (HALZ) domain that shares an amino acid percentage identity to the HALZ domain of any of SEQ ID NO: 2-20;   wherein the amino acid percentage identity is selected from the group consisting of at least 60%, at least 61%, at least 62%, at least 63%, at least 64%, at least 65%, at least 66%, at least 67%, at least 68%, at least 69%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, and about 100%;   wherein said polypeptide confers the improved trait which is selected from the group consisting of: higher nitrogen use efficiency, greater stomatal conductance, lower chlorophyll levels, greater size, greater biomass, greater yield, and a greater growth rate, when the polypeptide is expressed in the transgenic plant;   wherein the first control plant comprises a recombinant polynucleotide encoding any of SEQ ID NO: 2-20.   
     
     
         2 . The transgenic plant of  claim 1 , wherein the transgenic plant has improved traits relative to a second control plant of the same species, wherein the second control plant is a wild type or non-transformed plant of the same species;
 wherein the improved trait is selected from the group consisting of higher nitrogen use efficiency, greater size, greater biomass, greater yield, greater growth rate, greater chlorophyll levels, greater photosynthetic capacity, greater photosynthetic rate and greater stomatal conductance.   
     
     
         3 . The transgenic plant of  claim 1 , wherein the polypeptide is at least 30%, at least 31%, at least 32%, at least 33%, at least 34%, at least 35%, at least 36%, at least 37%, at least 38%, at least 39%, at least 40%, at least 41%, at least 42%, at least 43%, at least 44%, at least 45%, at least 46%, at least 47%, at least 48%, at least 49%, at least 50%, at least 51%, at least 52%, at least 53%, at least 54%, at least 55%, at least 56%, at least 57%, at least 58%, at least 59%, at least 60%, at least 61%, at least 62%, at least 63%, at least 64%, at least 65%, at least 66%, at least 67%, at least 68%, at least 69%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or about 100% identical to the full length sequence of any of SEQ ID NO: 2-20. 
     
     
         4 . The transgenic plant of  claim 1 ,  2  or  3 , wherein X 1  or X 3 , or both X 1  and X 3  are alanine residues. 
     
     
         5 . The transgenic plant of  claim 1 ,  2 ,  4 , or  5 , wherein the polypeptide is SEQ ID NO: 21. 
     
     
         6 . The transgenic plant of any of  claims 1 - 5 , wherein the transgenic plant is a C3 plant. 
     
     
         7 . The transgenic plant of  claim 1 , wherein the transgenic plant is a legume. 
     
     
         8 . The transgenic plant of  claim 1 , wherein the transgenic legume plant is a soybean plant. 
     
     
         9 . A plant material or plant part produced from the transgenic plant of any of  claims 1 - 8 , wherein the plant material or plant part comprises the polypeptide. 
     
     
         10 . A transgenic seed produced by the transgenic plant of any of  claims 1 - 9 . 
     
     
         11 . The transgenic plant of  claim 4 , wherein X 2  is Aspartic acid and X 4  is threonine. 
     
     
         12 . A method for conferring an improved trait to a plant, the method comprising:
 (a) providing a polynucleotide encoding a first Class II HD-Zip subfamily polypeptide that comprises
 (1) a consensus EAR motif set forth as SEQ ID NO: 50; 
 (2) a homeodomain that shares an amino acid percentage identity to a homeodomain of any of SEQ ID NO: 2-20; and 
 (3) a homeobox-associated leucine zipper (HALZ) domain that shares an amino acid percentage identity to a HALZ domain set forth in any of SEQ ID NO: 2-20;
 wherein the amino acid percentage identity is selected from the group consisting of: at least 60%, at least 61%, at least 62%, at least 63%, at least 64%, at least 65%, at least 66%, at least 67%, at least 68%, at least 69%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, and about 100%; 
 
   (b) mutagenizing the polynucleotide, wherein the mutagenized polynucleotide encodes a mutant polypeptide comprising a mutant EAR motif of X 1 -X 2 -X 3 -X 4 -X 5  (set forth in SEQ ID NO: 1), where X 1  and X 3  are any amino acid other than leucine, isoleucine or valine; and X 5  is isoleucine, leucine or methionine;   (c) introducing the mutagenized polynucleotide into a target plant to produce a transgenic plant, wherein expression of the mutagenized polynucleotide confers the improved trait in the transgenic plant; and   (d) optionally, selecting the transgenic plant having the improved trait;
 wherein the improved trait is selected from the group consisting of: greater nitrogen use efficiency, greater stomatal conductance, greater chlorophyll levels, greater photosynthetic capacity, greater photosynthetic rate, greater stomatal conductance, greater size, greater biomass, and greater yield relative to a wild-type or non-transformed control plant of the same species. 
   
     
     
         13 . The method of  claim 12 , wherein the first polypeptide is at least 30%, at least 31%, at least 32%, at least 33%, at least 34%, at least 35%, at least 36%, at least 37%, at least 38%, at least 39%, at least 40%, at least 41%, at least 42%, at least 43%, at least 44%, at least 45%, at least 46%, at least 47%, at least 48%, at least 49%, at least 50%, at least 51%, at least 52%, at least 53%, at least 54%, at least 55%, at least 56%, at least 57%, at least 58%, at least 59%, at least 60%, at least 61%, at least 62%, at least 63%, at least 64%, at least 65%, at least 66%, at least 67%, at least 68%, at least 69%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or about 100% identical to the full length sequence of any of SEQ ID NO: 2-20. 
     
     
         14 . The method of  claim 12  or  claim 13 , wherein X 1  or X 3 , or both X 1  and X 3  are alaninc. 
     
     
         15 . The method of  claim 12 ,  13 , or  14 , wherein the transgenic plant is a C3 plant. 
     
     
         16 . The method of  claim 15 , wherein the transgenic C3 plant is a dicot plant. 
     
     
         17 . The method of  claim 15 , wherein the transgenic C3 plant is a legume. 
     
     
         18 . The method of  claim 15 , wherein the transgenic C3 plant is a soybean plant. 
     
     
         19 . The method of any of  claims 12 - 18 , wherein the transcriptional repression activity of the mutant polypeptide is less than that of the first polypeptide. 
     
     
         20 . A class II HD-Zip polypeptide that comprises, in order from N-terminus to C-terminus:
 (a) a mutant EAR motif comprising a sequence of X 1 -X 2 -X 3 -X 4 -X 5  (set forth in SEQ ID NO: 1), where X 1  and X 3  are any amino acid other than leucine, isoleucine or valine; X 4  is any amino acid; and X 5  is isoleucine, leucine or methionine;   (b) a homeodomain that shares an amino acid percentage identity to a homeodomain of any of SEQ ID NO: 2-20; and   (c) a homeobox-associated leucine zipper (HALZ) domain that shares an amino acid percentage identity to a HALZ domain set forth in any of SEQ ID NO: 2-20.   
     
     
         21 . The class II HD-Zip polypeptide of  claim 20 , wherein X 1 , or X 3 , or both X 1  and X 3  are alanine.