Identification of a new class of epsp synthases

Abstract

Compositions and methods for conferring tolerance to glyphosate in bacteria, plants, plant cells, tissues and seeds are provided. Compositions include a novel class of EPSPS enzymes, designated Class III, and polynucleotides encoding such enzymes, vectors comprising those polynucleotides, and host cells comprising the vectors. The novel proteins comprise at least one sequence domain selected from the Class III domains provided herein. These sequence domains can be used to identify EPSP synthases with glyphosate resistance activity.

1 . A recombinant polynucleotide encoding a glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase enzyme, wherein said polynucleotide is selected from the group consisting of:
 a) the nucleotide sequence of SEQ ID NO:1, 45, 47, and 55;   b) a nucleotide sequence that encodes a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 46, 48, and 56; and,   c) a nucleotide sequence encoding a polypeptide having at least 95% amino acid sequence identity to the amino acid sequence of SEQ ID NO:2, 46, 48, and 56, wherein said nucleotide sequence encodes a glyphosate tolerant EPSP synthase enzyme,   
       wherein said polynucleotide is operably linked to a promoter that drives expression of said polynucleotide in a plant cell. 
     
     
         2 . The polynucleotide of  claim 1 , wherein said promoter is heterologous with respect to the polynucleotide. 
     
     
         3 . The polynucleotide of  claim 1  in which the polynucleotide encodes a fusion polypeptide comprising an amino-terminal chloroplast transit peptide and the EPSP synthase enzyme. 
     
     
         4 . A glyphosate-tolerant plant cell comprising the polynucleotide of  claim 1 . 
     
     
         5 . The glyphosate-tolerant plant cell of  claim 4  selected from the group consisting of corn, wheat, rice, barley, soybean, cotton, sugarbeet, oilseed rape, canola, flax, sunflower, potato, tobacco, tomato, alfalfa, poplar, pine, eucalyptus, apple, lettuce, peas, lentils, grape and turf grasses. 
     
     
         6 . A glyphosate-tolerant plant comprising the plant cell of  claim 4 . 
     
     
         7 . The glyphosate-tolerant plant of  claim 6  selected from the group consisting of corn, wheat, rice, barley, soybean, cotton, sugarbeet, oilseed rape, canola, flax, sunflower, potato, tobacco, tomato, alfalfa, poplar, pine, eucalyptus, apple, lettuce, peas, lentils, grape and turf grasses. 
     
     
         8 . A transgenic seed comprising the polynucleotide of  claim 1 . 
     
     
         9 . A method of producing genetically transformed plants which are tolerant toward glyphosate herbicide, comprising the steps of:
 a) inserting into the genome of a plant cell a polynucleotide comprising a promoter which functions in plant cells to cause the production of an RNA sequence operably linked to a nucleotide sequence encoding a glyphosate-tolerant 5-EPSP synthase enzyme, wherein said nucleotide sequence is selected from the group consisting of:
 i) the nucleotide sequence of SEQ ID NO:1, 45, 47, and 55; 
 ii) a nucleotide sequence that encodes a polypeptide comprising the amino acid sequence of SEQ ID NO:2, 46, 48, and 56; and, 
 iii) a nucleotide sequence encoding a polypeptide having at least 95% amino acid sequence identity to the amino acid sequence of SEQ ID NO:2, 46, 48, and 56, wherein said nucleotide sequence encodes a glyphosate-tolerant EPSP synthase enzyme; 
   b) obtaining a transformed plant cell; and   c) regenerating from the transformed plant cell a genetically transformed plant which has increased tolerance to glyphosate herbicide.   
     
     
         10 . The method of  claim 9 , wherein obtaining the transformed plant comprises screening for an enhanced tolerance to glyphosate herbicide. 
     
     
         11 . The method of  claim 9  in which the polynucleotide encodes a fusion polypeptide comprising an amino-terminal chloroplast transit peptide and the EPSP synthase enzyme. 
     
     
         12 . A method for selectively controlling weeds in a field having planted seeds or plants comprising the steps of:
 a) growing in said field the plant of  claim 6  or a transgenic seed obtained therefrom, and   b) applying to the plants and weeds in the field a sufficient amount of glyphosate herbicide to control the weeds without significantly affecting the plants.   
     
     
         13 . A method for increasing yield in a plant comprising growing in a field the plant of  claim 6  or a transgenic seed obtained therefrom and applying to the plant an effective concentration of glyphosate herbicide.