Rubisco activase with increased thermostability and methods of use thereof

Abstract

The present invention provides thermostable polypeptides related to Arabidopsis Rubisco Activase polypeptides. Nucleic acids encoding the polypeptides of the invention are also provided. Methods for using the polypeptides and nuclei acids of the invention to enhance resistance of plants to heat stress are encompassed.

1 . An isolated nucleic acid molecule comprising any of SEQ ID NOS: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21 or a complement thereof. 
     
     
         2 . An isolated nucleic acid molecule selected from the group consisting of:
 a. a nucleic acid molecule comprising a nucleotide sequence which is at least 95% identical to the nucleotide sequence of any of SEQ ID NOS: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21 or a complement thereof;   b. a nucleic acid molecule that encodes a polypeptide comprising the amino acid sequence of any of SEQ ID NOS: 4, 6, 8, 10, 12, 14, 16, 18, 20, 22; and   c. a nucleic acid molecule that hybridizes under stringent conditions with a nucleic acid probe consisting of the nucleotide sequence of any of SEQ ID NOS: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21 or a complement thereof.   
     
     
         3 . The isolated nucleic acid molecule of  claim 1  or  2 , wherein the nucleic acid molecule encodes a polypeptide with increased thermostability as compared to a polypeptide of SEQ ID NO: 2. 
     
     
         4 . A vector comprising a nucleic acid molecule of  claim 1  or  2 . 
     
     
         5 . The vector of  claim 4  that is an expression vector. 
     
     
         6 . A host cell which comprises the vector of  claim 4 . 
     
     
         7 . An isolated polypeptide comprising any one of SEQ ID NOS: 4, 6, 8, 10, 12, 14, 16, 18, 20, 22. 
     
     
         8 . An isolated polypeptide selected from the group consisting of:
 a. a polypeptide that is at least 95% identical to the amino acid sequence of any of SEQ ID NOS: 4, 6, 8, 10, 12, 14, 16, 18, 20, 22;   b. a polypeptide that is encoded by a nucleic acid molecule comprising a nucleotide sequence that is at least 95% identical to any one of SEQ ID NOS: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21 or a complement thereof;   c. polypeptide encoded by a nucleic acid molecule that hybridizes under stringent conditions with a nucleic acid probe consisting of the nucleotide sequence of any of SEQ ID NOS: 3, 5, 7, 9, 11, 13, 15, 17, 19, 21 or a complement thereof.   
     
     
         9 . The isolated polypeptide of  claim 7  or  8 , wherein the polypeptide has increased thermostability as compared to a polypeptide of SEQ ID NO: 2. 
     
     
         10 . A transgenic plant comprising a transgene that expresses
 a. a polypeptide of  claim 8 , or   b. a nucleic acid molecule of  claim 2 .   
     
     
         11 . The transgenic plant of  claim 10 , wherein the plant is selected from the group consisting of maize, tomato, potato, rice, soybean, cotton, sunflower, alfalfa, lettuce, canola, sorghum or tobacco plants. 
     
     
         12 . The transgenic plant of  claim 10 , wherein the transgenic plant has increased heat tolerance as compared to a plant that is not transgenic. 
     
     
         13 . A method of increasing the heat tolerance in plants comprising expressing a polypeptide of any of SEQ ID NOS: 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 in the plant. 
     
     
         14 . The method of  claim 13 , wherein the polypeptide is expressed in the one or more plastids of the plant. 
     
     
         15 . The method according to  claim 13 , wherein the expression of said polypeptide results in an increase in photosynthesis rate under heated conditions.