Plants with enhanced ability to produce starch and methods for obtaining them

Abstract

The subject invention concerns materials and methods for enhancing starch production in plants. Starch production is enhanced, relative to levels observed in wildtype or control plants, by reduction of the plant 14-3-3 protein(s) which subsequently results in increased accumulation of starch in the plant. In one embodiment, the 14-3-3 protein expression is reduced using polynucleotides that are antisense to the 14-3-3 gene sequences expressed in the plant. In another embodiment, the 14-3-3 protein expression is reduced by “knockout” of a 14-3-3 gene or gene sequences. The subject invention also pertains to transformed and transgenic plants that have polynucleotides that are antisense to the 14-3-3 gene sequences expressed in the plant, wherein the transformed and transgenic plants exhibit enhanced starch production. The subject invention also pertains to “knockout” plants in which the normal functional 14-3-3 gene in the plant is deleted or replaced with a non-functional form of the gene. The subject invention also concerns the “antisense” polynucleotides of the invention that when introduced into a plant cell can function to effectively reduce expression of the 14-3-3 proteins in a plant.

1 . A method for enhancing starch production in a plant, said method comprising inhibiting the expression of a 14-3-3 protein of said plant or inhibiting function of a 14-3-3 protein of said plant.  
     
     
         2 . The method according to  claim 1 , wherein a polynucleotide encoding a plant 14-3-3 protein, or a fragment thereof, is introduced into a plant cell of said plant.  
     
     
         3 . The method according to  claim 2 , wherein said polynucleotide is provided in a recombinant vector.  
     
     
         4 . The method according to  claim 2 , wherein said polynucleotide is introduced by  Agrobacterium  infection, biolistic transfection, electroporation, microinjection, or virus-mediated transformation of said cell.  
     
     
         5 . The method according to  claim 2 , wherein said polynucleotide encodes a 14-3-3 Mu protein, or a fragment thereof.  
     
     
         6 . The method according to  claim 5 , wherein said 14-3-3 Mu protein has the amino acid sequence shown in SEQ ID NO. 4.  
     
     
         7 . The method according to  claim 6 , wherein said polynucleotide comprises the coding sequence of the nucleotide sequence shown in SEQ ID NO. 3.  
     
     
         8 . The method according to  claim 2 , wherein said polynucleotide encodes a 14-3-3 Epsilon protein, or a fragment thereof  
     
     
         9 . The method according to  claim 5 , wherein said 14-3-3 Epsilon protein has the amino acid sequence shown in SEQ ID NO. 2.  
     
     
         10 . The method according to  claim 9 , wherein said polynucleotide comprises the coding sequence of the nucleotide sequence shown in SEQ ID NO. 1.  
     
     
         11 . The method according to  claim 2 , wherein a plant is grown from said cell in which said polynucleotide has been introduced.  
     
     
         12 . The method according to  claim 1 , wherein expression of said 14-3-3 protein is inhibited by: 
 a) expressing a polynucleotide in said plant that has a nucleotide sequence that is antisense to the nucleotide sequence that encodes said 14-3-3 protein; or    b) deleting the nucleotide sequence that encodes said 14-3-3 protein or replacing the nucleotide sequence that encodes said 14-3-3 protein with a nucleotide sequence that encodes a non-functional form of said 14-3-3 protein or that renders said 14-3-3 protein non-functional    
     
     
         13 . The method according to  claim 1 , wherein function of said 14-3-3 protein is inhibited by expressing a polynucleotide that encodes an antibody, a functional fragment of said antibody, or an aptamer in said plant, wherein said antibody and said aptamer can bind to and inhibit the function of said 14-3-3 proteins in said plant.  
     
     
         14 . The method according to  claim 1 , wherein said plant is a monocot.  
     
     
         15 . The method according to  claim 1 , wherein said plant is a dicot.  
     
     
         16 . A method for preparing a plant that exhibits enhanced starch production, said method comprising: 
 a) deleting all or aportion of a nucleotide sequence of said plant that encodes a 14-3-3 protein or replacing the nucleotide sequence of said plant that encodes said 14-3-3 protein with a nucleotide sequence that encodes a non-functional form of said 14-3-3 protein or that renders said 14-3-3 protein non-functional; or    b) inhibiting expression of a 14-3-3 protein of said plant by introducing a polynucleotide encoding a plant 14-3-3 protein, or a fragment thereof, into said plant or inhibiting function of a 14-3-3 protein of said plant by introducing into and expressing in said plant a polynucleotide that encodes an antibody, a functional fragment of said antibody, or an aptamer to said 14-3-3 protein, wherein said antibody and said aptamer can bind to and inhibit the function of said 14-3-3 proteins in said plant; or    c) introducing into said plant a polynucleotide that comprises a nucleotide sequence that is antisense to the nucleotide sequence that encodes a 14-3-3 protein.    
     
     
         17 . A plant or plant material exhibiting enhanced starch production, wherein expression or function of a 14-3-3 protein of said plant or plant material is inhibited.  
     
     
         18 . The plant or plant material according to  claim 17 , wherein said plant is a monocot or said plant material is from a monocot plant.  
     
     
         19 . The plant or plant material according to  claim 18 , wherein said monocot is selected from the group consisting of maize, wheat, barley, rice, and oats.  
     
     
         20 . The plant or plant material according to  claim 17 , wherein said plant is a dicot or said plant material is from a dicot plant.  
     
     
         21 . The plant or plant material according to  claim 20 , wherein said dicot is selected from the group consisting of tobacco, potato, cabbage, soybeans, and sweet potato.  
     
     
         22 . The plant or plant material according to  claim 17 , wherein said plant or plant material is produced according to the method of  claim 16 .  
     
     
         23 . The plant or plant material according to  claim 17 , wherein said plant material is selected from the group consisting of plant tissue, plant cells, plant seeds, and protoplasts.