Wuschel (WUS) Gene Homologs

Abstract

This invention relates to isolated polynucleotides encoding WUS polypeptides. The invention further provides isolated WUS polypeptides. The invention also provides methods of using the polynucleotides to modulate the level of WUS, improve transformation efficiency, to stimulate plant cell growth, including stem cells, to stimulate organogenesis, to stimulate somatic embryogenesis, to induce apomixis, and to provide a positive selection for cells comprising the polynucleotide. The invention also relates to cells, plants and seeds comprising the polynucleotides of the invention or produced by the methods of the invention.

1 . An isolated polynucleotide comprising a nucleotide sequence encoding a WUSCHEL polypeptide containing a 1+4 homeodomain, wherein the polypeptide has at least 80% sequence identity over its entire length to SEQ ID NO: 14 based on the CLUSTAL alignment method using default parameters of KTUPLE 1, GAP PENALTY=3, WINDOW=5 and DIAGONALS SAVED=5, and wherein the polypeptide is capable of stimulating in vitro growth of plant tissue.  
     
     
         2 . An isolated polynucleotide fully complementary to the polynucleotide of  claim 1 .  
     
     
         3 . The isolated polynucleotide of  claim 1 , wherein the WUSCHEL polypeptide has at least 85% sequence identity over its entire length to SEQ ID NO: 14.  
     
     
         4 . The isolated polynucleotide of  claim 1 , wherein the WUSCHEL polypeptide has at least 90% sequence identity over its entire length to SEQ ID NO: 14.  
     
     
         5 . The isolated polynucleotide of  claim 1 , wherein the WUSCHEL polypeptide has at least 95% sequence identity over its entire length to SEQ ID NO: 14.  
     
     
         6 . The isolated polynucleotide of  claim 1 , wherein the nucleotide sequence comprises SEQ ID NO: 13.  
     
     
         7 . A chimeric gene comprising the polynucleotide of  claim 1 , operably linked to a regulatory sequence functional in a host cell.  
     
     
         8 . A transgenic plant comprising the polynucleotide of  claim 1 .  
     
     
         9 . A seed from the transgenic plant of  claim 8 , wherein the seed comprises the polynucleotide.  
     
     
         10 . The seed of  claim 9 , wherein the seed is from a plant selected from the group consisting of corn, soybean, wheat, rice, alfalfa, sunflower, canola, or cotton.  
     
     
         11 . A method for inducing meristem proliferation in a plant cell comprising: 
 (a) transforming a plant cell with a polynucleotide of  claim 1  operably linked to a regulatory sequence operable in the plant cell; and,    (b) expressing the polynucleotide for a time sufficient to induce meristem proliferation.    
     
     
         12 . The method of  claim 11  wherein the polynucleotide is integrated into the plant cell genome to produce a transformed plant cell comprising the polynucleotide.  
     
     
         13 . The method of  claim 12  further comprising growing the transformed plant cell under plant growing conditions to produce a regenerated plant.  
     
     
         14 . A plant produced by the method of  claim 13 .  
     
     
         15 . A method for positive selection of a transformed cell, comprising: 
 (a) transforming a plant cell with a polynucleotide of  claim 1  operably linked to a regulatory sequence operable in the plant cell; and,    (b) expressing the polynucleotide for a time sufficient to induce organogenesis and provide a positive selection means.    
     
     
         16 . The method of  claim 15  wherein the polynucleotide is integrated into the plant cell genome to produce a transformed plant cell comprising the polynucleotide.  
     
     
         17 . The method of  claim 16  further comprising growing the transformed plant cell under plant growing conditions to produce a regenerated plant.  
     
     
         18 . A plant produced by the method of  claim 17 .  
     
     
         19 . A method for transforming a plant cell comprising introducing the polynucleotide of  claim 1  into the cell.  
     
     
         20 . A transformed plant cell produced by the method of  claim 19 , wherein the cell comprises the polynucleotide.  
     
     
         21 . A transformed plant regenerated from the plant cell of  claim 20 , wherein the plant comprises the polynucleotide.  
     
     
         22 . A method to increase transformation frequency comprising: 
 (a) introducing into a plant cell the isolated polynucleotide of  claim 1  operably linked to a regulatory sequence operable in the plant cell; and,    (b) expressing the polynucleotide in the plant cell;    wherein plant cells expressing the polynucleotide have an increased transformation frequency as compared to control plant cells that do not have or express the polynucleotide.    
     
     
         23 . A method to stimulate plant cell growth, wherein the method comprises: 
 (a) introducing into a plant cell the isolated polynucleotide of  claim 1  operably linked to a regulatory sequence operable in the plant cell; and,    (b) expressing the polynucleotide in the plant cell;, wherein plant cells expressing the polynucleotide show stimulated plant cell growth as compared to control plant cells that do not have or express the polynucleotide.