Herbicide-resistant rice plants, polynucleotides encoding herbicide-resistant acetohydroxyacid synthase large subunit proteins, and methods of use

Abstract

Herbicide-resistant rice plants, isolated polynucleotides that encode herbicide resistant and wild-type acetohydroxy-acid synthase large subunit 1 (AHASL1) polypeptides, and the amino acid sequences of these polypeptides, are described. Expression cassettes and transformation vectors comprising the polynucleotides of the invention, as well as plants and host cells transformed with the polynucleotides, are described. Methods of using the polynucleotides to enhance the resistance of plants to imidazolinone herbicides, and methods for controlling weeds in the vicinity of herbicide-resistant plants are also described.

What is claimed is: 
     
         1 . A method for treating rice, comprising:
 providing a rice crop plant and at least one AHAS-inhibiting herbicide;   applying an effective amount of the at least one AHAS-inhibiting herbicide to the rice crop plant, post-emergence; thereby creating a treated rice plant; and   growing the resulting treated rice plant.   
     
     
         2 . The method of  claim 1 , further comprising harvesting seed from the treated rice plant. 
     
     
         3 . The method of  claim 1 , wherein the rice crop plant comprises in its genome at least one copy of a rice acetohydroxyacid synthase large subunit (AHASL1) polynucleotide that encodes a herbicide-tolerant AHASL1 protein, and wherein said herbicide-tolerant AHASL1 protein provides the rice crop plant with increased tolerance to at least one AHAS-inhibiting herbicide as compared to a wild-type rice crop plant. 
     
     
         4 . The method of  claim 3 , wherein the AHASL1 protein comprises a leucine substitution at a position corresponding to position 171 of SEQ ID NO:2. 
     
     
         5 . The method of  claim 1 , wherein the AHAS-inhibiting herbicide comprises one or more of an imidazolinone herbicide, a sulfonylurea herbicide, a triazolopyrimidine herbicide, a pyrimidinyloxybenzoate herbicide, and a sulfonylaminocarbonyltriazolinone herbicide. 
     
     
         6 . The method of  claim 5 , wherein the AHAS-inhibiting herbicide comprises a sulfonylurea herbicide. 
     
     
         7 . The method of  claim 6 , wherein the sulfonylurea herbicide comprises one or more of chlorsulfuron, metsulfuron, metsulfuron methyl, sulfometuron, sulfometuron methyl, chlorimuron, chlorimuron ethyl, thifensulfuron, thifensulfuron methyl, tribenuron, tribenuron methyl, bensulfuron, bensulfuron methyl, nicosulfuron, ethametsulfuron, ethametsulfuron methyl, rimsulfuron, triflusulfuron, triflusulfuron methyl, triasulfuron, primisulfuron, primisulfuron methyl, cinosulfuron, amidosulfiuon, fluzasulfuron, imazosulfuron, pyrazosulfuron, pyrazosulfuron ethyl, halosulfuron, azimsulfuron, cyclosulfuron, ethoxysulfuron, flazasulfuron, flupyrsulfuron, flupyrsulfuron methyl, foramsulfuron, iodosulfuron, oxasulfuron, mesosulfuron, prosulfuron, sulfosulfuron, trifloxysulfuron, tritosulfuron, and derivatives thereof. 
     
     
         8 . The method of  claim 7 , wherein the sulfonylurea herbicide comprises one or more of chlorsulfuron, flazasulfuron, flucetosulfuron, flupyrsulfuron, flupyrsulfuron methyl, foramsulfuron, mesosulfuron, nicosulfuron, primisulfuron, primisulfuron methyl, rimsulfuron, sulfometuron, sulfometuron methyl, sulfusulfuron, and derivatives thereof. 
     
     
         9 . The method of  claim 5 , wherein the AHAS-inhibiting herbicide comprises an imidazolinone herbicide. 
     
     
         10 . The method of  claim 9 , wherein the imidazolinone herbicide comprises one or more of imazethapyr, imazapic, imazamox, imazaquin, imazethabenz, imazapyr, and derivatives thereof. 
     
     
         11 . The method of  claim 9 , wherein the imidazolinone herbicide comprises imazethapyr. 
     
     
         12 . The method of  claim 1 , wherein the effective amount is effective for killing a weed of one or more of the genera  Echinochloa, Setaria, Panicum, Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus, Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristyslis, Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea, Dactyloctenium, Agrostis, Alopecurus,  and  Apera.    
     
     
         13 . The method of  claim 12 , wherein the effective amount is effective for killing a weed of one or more of the genera  Digitaria, Eleusine, Ischaemum, Paspalum,  and  Eleocharis.    
     
     
         14 . The method of  claim 1 , wherein the effective amount is effective for killing red rice.