Modified DMO enzyme and methods of its use
The invention provides a modified variant of dicamba monooxygenase (DMO). The invention relates to the unexpected finding that cells expressing this DMO exhibit high levels of tolerance to the herbicide dicamba. Compositions comprising DMO-encoding nucleic acids and methods of use are provided.
1. A nucleic acid molecule selected from the group consisting of:
a) a nucleic acid molecule encoding the polypeptide of SEQ ID NO:1;
b) a nucleic acid molecule comprising the sequence of SEQ ID NO:2; and
c) a nucleic acid molecule encoding a polypeptide with at least 90% sequence identity to the polypeptide of SEQ ID NO:1, wherein the polypeptide has dicamba monooxygenase activity and comprises cysteine at a position corresponding to amino acid 112 of SEQ ID NO:1.
2. The nucleic acid molecule of claim 1 , wherein the nucleic acid molecule encodes the dicamba monooxygenase encoded by plasmid pKLP36-TEV-TP-DMOc (ATCC Accession No. PTA-7357).
3. A DNA construct comprising the nucleic acid molecule of claim 1 operably linked to a promoter.
4. The construct of claim 3 , wherein the promoter is functional in a plant cell.
5. The construct of claim 3 , wherein the nucleic acid molecule is operably linked to a chloroplast transit peptide.
6. A method of producing a dicamba tolerant plant comprising introducing into the plant the construct of claim 3 .
7. The method of claim 6 , comprising introducing said construct into said plant by stably transforming a starting plant cell and regenerating the cell into said dicamba tolerant plant.
8. The method of claim 6 , wherein the dicamba tolerant plant is produced by crossing a parent plant with itself or a second plant, wherein the parent plant and/or the second plant comprises the transformation construct and the dicamba tolerant plant inherits the transformation construct from said parent plant and/or the second plant.
9. A plant cell transformed with the nucleic acid molecule of claim 1 .
10. The cell of claim 9 , wherein the plant cell is a dicotyledonous plant cell.
11. The cell of claim 10 , wherein the dicotyledonous plant cell is a soybean, cotton, maize or rapeseed plant cell.
12. The cell of claim 9 , wherein the plant cell is a monocotyledonous plant cell.
13. A plant tissue culture comprising the cell of claim 9 .
14. A transgenic plant transformed with the nucleic acid molecule of claim 1 .
15. The transgenic plant of claim 14 , wherein the plant is a dicotyledonous plant.
16. The transgenic plant of claim 14 , wherein the plant is a monocotyledonous plant.
17. The transgenic plant of claim 14 , wherein the plant is a soybean, cotton, maize or rapeseed plant.
18. A method of controlling weed growth in a crop growing environment comprising a plant of claim 14 or a seed thereof, the method comprising applying to the crop growing environment an amount of dicamba herbicide effective to control weed growth.
19. The method of claim 18 , wherein the dicamba herbicide is applied over the top to the crop growing environment.
20. The method of claim 18 , wherein the amount of dicamba herbicide does not damage said plant or seed thereof and damages a plant of the same genotype as the plant lacking the nucleic acid.
21. A polypeptide sequence comprising an amino acid sequence with at least 90% identity to SEQ ID NO:1, wherein the polypeptide has dicamba monooxygenase activity and comprises cysteine at a position corresponding to amino acid 112 of SEQ ID NO:1.
22. A method of producing food, feed or an industrial product comprising:
a) obtaining the plant of claim 14 or a part thereof; and
b) preparing the food, feed or industrial product from the plant or part thereof.
23. The method of claim 22 , wherein the food or feed is oil, meal, grain, starch, flour, or protein.
24. The method of claim 22 , wherein the industrial product is biofuel, fiber, industrial chemicals, a pharmaceutical or nutraceutical.