Methods of controlling seed size in plants

Abstract

This invention relates to the identification of a regulator protein (termed CYP78A6, or EOD3) which controls the size of plant seeds and organs in Arabidopsis and other plants. Manipulation of CYP78A protein expression may useful, for example, in improving crop yield and increasing plant biomass.

1 . A method of modulating seed size in a plant comprising reducing or abolishing expression of a CYP78A polypeptide within cells of said plant,
 wherein said reduced or abolished expression reduces seed size in said plant.   
     
     
         2 . A method according to  claim 1  comprising expressing a heterologous nucleic encoding an RNA molecule which suppresses expression of a CYP78A polypeptide within cells of said plant. 
     
     
         3 . A method according to  claim 2  comprising mutating a nucleic acid coding sequence encoding a CYP78A polypeptide within cells of said plant or a nucleic acid which regulates the expression of said nucleic acid coding sequence. 
     
     
         4 . A method according to  claim 3  comprising mutating a nucleic acid which regulates the expression of said nucleic acid coding sequence. 
     
     
         5 . A method of producing a plant with an altered seed size comprising:
 incorporating a heterologous nucleic acid which alters the expression of a CYP78A polypeptide into a plant cell by means of transformation, and;   regenerating the plant from one or more transformed cells.   
     
     
         6 . A method according to  claim 5  wherein the heterologous nucleic acid inactivates an element which represses expression of a CYP78A6 polypeptide. 
     
     
         7 . A method according to  claim 5  wherein the heterologous nucleic acid reduces expression of the CYP78A polypeptide and the seed size of the plant is reduced. 
     
     
         8 . A method according to  claim 7  wherein the heterologous nucleic acid encodes an RNA molecule which suppresses a CYP78A polypeptide. 
     
     
         9 . A method according to  claim 7  wherein the heterologous nucleic acid inactivates the expression of a CYP78A polypeptide. 
     
     
         10 . A method according to  claim 1  further comprising incorporating a heterologous nucleic acid which expresses a suppressor nucleic acid which reduces expression of a DA polypeptide into said plant cell by means of transformation or expressing a heterologous nucleic acid which encodes suppressor nucleic acid which reduces expression of a DA polypeptide in said plant.