Novel herbicide resistance genes

Abstract

The subject invention provides novel plants that are not only resistant to 2,4-D and other phenoxy auxin herbicides, but also to aryloxyphenoxypropionate herbicides. Heretofore, there was no expectation or suggestion that a plant with both of these advantageous properties could be produced by the introduction of a single gene. The subject invention also includes plants that produce one or more enzymes of the subject invention alone or “stacked” together with another herbicide resistance gene, preferably a glyphosate resistance gene, so as to provide broader and more robust weed control, increased treatment flexibility, and improved herbicide resistance management options. More specifically, preferred enzymes and genes for use according to the subject invention are referred to herein as AAD (aryloxyalkanoate dioxygenase) genes and proteins. No α-ketoglutarate-dependent dioxygenase enzyme has previously been reported to have the ability to degrade herbicides of different chemical classes and modes of action. This highly novel discovery is the basis of significant herbicide tolerant crop trait opportunities as well as development of selectable marker technology. The subject invention also includes related methods of controlling weeds. The subject invention enables novel combinations of herbicides to be used in new ways. Furthermore, the subject invention provides novel methods of preventing the formation of, and controlling, weeds that are resistant (or naturally more tolerant) to one or more herbicides such as glyphosate.

1 . A method of producing a modified plant having enhanced tolerance to a phenoxy auxin herbicide as compared to the modified plant in its previous unmodified condition, said method comprising
 introducing a polynucleotide encoding an AAD-1 protein into the cells of a plant to produce said modified plant, wherein said encoded AAD-1 protein comprises:   i) an amino acid sequence having at least 85% sequence identity with SEQ ID NO: 9; and   ii) an AAD-1 motif having the general formula of: HX 112 D(X) 114-137 T(X) 139-269 H(X) 271-280 R, wherein
 X 112  represents a single amino acid at position 112, relative to the sequence of SEQ ID NO: 9; 
 (X) 114-137  represents a sequence of 24 amino acids; 
 (X) 139-269  represents a sequence of 131 amino acids; and 
 (X) 271-280  represents a sequence of 10 amino acids 
   further wherein said AAD-1 protein when expressed in a plant cell renders said plant cell tolerant to a phenoxy auxin herbicide and an (R)-aryloxyphenoxypropionate herbicide, as compared to an untransformed plant cell of the same plant.   
     
     
         2 . The method of  claim 1  wherein the step of introducing said polynucleotide comprises:
 subjecting a plurality of plant cells to transformation with said polynucleotide, then growing said cells in a concentration of a herbicide that permits transformed cells that express said polynucleotide to grow while killing or inhibiting the growth of nontransformed cells; and 
 regenerating a plant from said transformed cells. 
 
     
     
         3 . The method of  claim 1  wherein the step of introducing said polynucleotide comprises:
 crossing a first plant lacking a polynucleotide that encodes an AAD-1 protein with a second plant comprising a polynucleotide that encodes an AAD-1 protein that exhibits aryloxyalkanoate dioxygenase activity, wherein said AAD-1 protein comprises: 
 i) an amino acid sequence having at least 85% sequence identity with SEQ ID NO: 9; and 
 ii) an AAD-1 motif having the general formula of:
 HX 112 D(X) 114-137 T(X) 139-269 H(X) 271-280 R, wherein
 X 112  represents a single amino acid at position 112, relative to the sequence of SEQ ID NO: 9; 
 (X) 114-137  represents a sequence of 24 amino acids; 
 (X) 139-269  represents a sequence of 131 amino acids; and 
 (X) 271-280  represents a sequence of 10 amino acids; and 
 
 
 selecting progeny plants that express the AAD-1 protein in the cells of the progeny plant. 
 
     
     
         4 . A plant cell comprising an expression cassette, wherein said expression cassette comprises
 a polynucleotide encoding an AAD-1 protein; and   a heterologous promoter that is functional in a plant cell, said heterologous promoter being operably linked to said polynucleotide,   wherein said AAD-1 protein comprises:   i) an amino acid sequence having at least 85% sequence identity with SEQ ID NO: 9; and   ii) an AAD-1 motif having the general formula of: HX 112 D(X) 114-137 T(X) 139-269 H(X) 271-280 R, wherein
 X 112  represents a single amino acid at position 112, relative to the sequence of SEQ ID NO: 9; 
 (X) 114-137  represents a sequence of 24 amino acids; 
 (X) 139-269  represents a sequence of 131 amino acids; and 
 (X) 271-280  represents a sequence of 10 amino acids 
   further wherein said AAD-1 protein when expressed in a plant cell renders said plant cell tolerant to a phenoxy auxin herbicide and an (R)-aryloxyphenoxypropionate herbicide, as compared to an untransformed plant cell of the same plant.   
     
     
         5 . A plant comprising a plurality of plant cells of  claim 4 . 
     
     
         6 . A seed from the plant of  claim 5 , wherein plant cells of said seed comprise said expression cassette. 
     
     
         7 . A method of protecting a crop plant from damage by an aryloxyalkanoate herbicide, said method comprising growing the plant of  claim 5 , and applying said herbicide to said plant. 
     
     
         8 . A method of making the plant cell of  claim 4  wherein said method comprises subjecting a plurality of plant cells to transformation with said polynucleotide, then growing said cells in a concentration of a herbicide that permits transformed cells that express said polynucleotide to grow while killing or inhibiting the growth of nontransformed cells. 
     
     
         9 . The plant cell of  claim 4  wherein said promoter is selected from the group consisting of cassava vein mosaic virus promoter (CsVMV), AtUbi10 promoter, AtUbi3 promoter, OsAct1 promoter and ZmUbi1 promoter. 
     
     
         10 . The plant of  claim 5  wherein said plant further comprises an insect-resistance gene derived from an organism selected from the group consisting of  Bacillus thuringiensis, Photorhabdus , and  Xenorhabdus.    
     
     
         11 . The plant of  claim 5  wherein said plant further comprises a gene for an agronomic trait selected from the group consisting of fungal resistance, stress tolerance, increased yield, improved oil profile, improved fiber quality, viral resistance, delayed ripening, cold tolerance, and salt tolerance. 
     
     
         12 . The plant of  claim 5 , wherein said plant is a monocot. 
     
     
         13 . The plant of  claim 12 , wherein said monocot is selected from the group consisting of corn, rice, wheat, barley, rye, turf grass, oats, sorghum, and pasture grasses. 
     
     
         14 . A plant grown from the seed of  claim 6 . 
     
     
         15 . A regenerable part, progeny, or asexual propagate of the plant of  claim 5 , wherein said regenerable part, progeny, or asexual propagate comprises said expression cassette.