Methods for obtaining plant varieties

Abstract

The present invention relates to an isolated and purified DNA comprising a nucleotide sequence that encodes a polypeptide functionally involved in the DNA mismatch repair system of a plant.

1 - 36 . (canceled)  
     
     
         37 . An isolated and purified nucleic acid molecule comprising a nucleotide sequence encoding a polypeptide having the amino acid sequence of AtMSH6 (SEQ ID NO:31).  
     
     
         38 . The nucleic acid of  claim 37  further comprising a regulation element operably linked to said AtMSH6-encoding sequence.  
     
     
         39 . A plasmid or vector comprising the nucleic acid of  claim 38 .  
     
     
         40 . A plant cell stably transformed, transfected or electroporated with the plasmid or vector of  claim 39 .  
     
     
         41 . A plant comprising the cell of  claim 40 .  
     
     
         42 . A process for at least partially inactivating the DNA mismatch repair system of a plant cell comprising: 
 transforming or transfecting said plant cell with a nucleic acid comprising a regulation element operably linked to a nucleotide sequence encoding a polypeptide having the amino acid sequence of AtMSH6 (SEQ ID NO:31);    growing said cell under conditions that permit expression of said AtMSH6-encoding sequence; and    hereby inactivating the DNA mismatch repair system of said plant cell.    
     
     
         43 . The process of  claim 42 , wherein said plant is selected from the group consisting of  Brassicaceae, Poaceae, Solanaceae, Asteraceae, Malvaceae, Fabaceae, Linaceae, Canabinaceae, Dauaceae , and  Curcubitaceae.    
     
     
         44 . A process for altering the mismatch repair system in a plant comprising introducing into said plant a chimeric gene expressing a polynucleotide which is capable of interfering with the expression of the nucleotide sequence encoding a AtMSH6 polypeptide (SEQ ID NO:31).  
     
     
         45 . The process of  claim 44 , wherein said chimeric gene expresses a polynucleotide that is antisense with regard to the nucleic acid molecule comprising a nucleotide sequence encoding said AtMSH6 polypeptide.