Method of selecting dna constructs for herbicide tolerance in plants

Abstract

An improved method for selecting among DNA constructs conferring herbicide tolerance for those which confer superior vegetative and reproductive tolerance in crop plants. Additionally, an improved method for selecting among DNA constructs conferring herbicide tolerance for those which confer superior tolerance in vegetative tissues of crop plants but little or no tolerance in male reproductive tissues of crop plants for the purpose of producing male sterile plants useful in a hybrid crop production system.

1 . A method of selecting a DNA construct effective for conferring herbicide tolerance in a crop plant from a plurality of DNA constructs, said method comprising:
 i) transforming a plant cell of a model plant with a DNA construct comprising a first DNA molecule that functions as a promoter of RNA transcription in a plant cell, operably linked to a second DNA molecule encoding a herbicide tolerance protein, operably linked to a third DNA molecule providing transcription termination in a plant cell;   ii) growing the transformed plant cell of a model plant into a transformed whole model plant;   iii) treating the transformed whole model plant prior to flower formation with an effective dose of a herbicide for which the herbicide tolerance gene is effective;   iv) scoring the transformed whole model plant for vegetative damage and reproductive fertility;   v) performing steps i-iv with at least one other DNA construct containing the same second DNA molecule encoding a herbicide tolerance protein but different in at least one of the first or third DNA molecules; and   vi) selecting at least one of said DNA constructs that provides a high level of herbicide tolerance to vegetative damage and a high level of herbicide tolerance to reproductive damage to the transformed whole model plant.   
     
     
         2 . A method of producing crop plants with effective herbicide tolerance comprising the steps of:
 i) using the method of  claim 1  to select at least one DNA construct that provides a high level of herbicide tolerance to vegetative damage and a high level of herbicide tolerance to reproductive damage to the transformed whole model plant;   ii) transforming the selected DNA construct or constructs into crop plant cells;   iii) regenerating the crop plant cells into whole crop plants;   iv) selecting said crop plants for herbicide tolerance by application of an effective dose of said herbicide; and   v) growing the surviving crop plants into fertile herbicide tolerant crop plants.   
     
     
         3 . The method of  claim 1  wherein said model plant is selected from the group consisting of  Arabidopsis  and micro-tomato. 
     
     
         4 . The method of  claim 1 , wherein said herbicide tolerance protein confers plant cell tolerance to herbicides selected from the group consisting of: glyphosate, glufosinate, sulfonylureas, imidazolinones, bromozynil, delapon, cyclohezanedione, protoporphyrionogen oxidase inhibitors, or isoxaslutole herbicides. 
     
     
         5 . The method of  claim 4  wherein said second DNA molecule is selected from the group consisting of glyphosate resistant EPSP synthases. 
     
     
         6 . The method of  claim 2  wherein the crop plant is a dicot. 
     
     
         7 . The method of  claim 6  wherein the crop plant is cotton or soybean, 
     
     
         8 . A method of producing crop plants with effective herbicide tolerance and acceptable fertility levels comprising:
 i) transforming a cell of  Arabidopsis thaliana  with a DNA construct comprising a first DNA molecule that functions as a promoter of RNA transcription in a plant cell, operably linked to a second DNA molecule encoding a glyphosate tolerance protein, operably linked to a third DNA molecule providing transcription termination in a plant cell;   ii) growing the transformed  Arabidopsis  cell into a transformed whole plant;   iii) treating the transformed whole plant prior to flower formation with an effective dose of glyphosate;   iv) scoring the transformed whole plant for vegetative damage and reproductive fertility;   v) performing steps i-iv with at least one other DNA construct containing the same second DNA molecule encoding a glyphosate tolerance protein but different in at least one of the first or third DNA molecules;   vi) selecting at least one of said DNA constructs that provides a high level of glyphosate tolerance to vegetative damage and a high level of glyphosate tolerance to reproductive damage to the transformed whole plant;   vii) transforming the selected DNA construct or constructs into crop plant cells;   viii) regenerating the crop plant cells into whole crop plants;   ix) selecting said crop plants for herbicide tolerance by application of an effective dose of glyphosate; and   x) growing said crop plant into a fertile glyphosate tolerant crop plant.   
     
     
         9 . A method of producing crop plants having effective vegetative herbicide tolerance and male reproductive intolerance in a crop plant comprising:
 i) transforming a plant cell of a model plant with a DNA construct containing a herbicide tolerance gene;   ii) growing the transformed plant cell of a model plant into a transformed whole model plant;   iii) treating the transformed whole model plant prior to flower formation with an effective dose of a herbicide for which the herbicide tolerance gene is effective;   iv) scoring the transformed whole model plant for vegetative damage and reproductive fertility;   v) repeating steps i-iv with a at least one other DNA construct containing the herbicide tolerance gene;   vi) selecting a DNA construct from said plurality of DNA constructs that provides a high level of tolerance to vegetative damage and a high level of reproductive infertility to the transformed whole model plant;   vii) transforming the selected DNA construct into a crop plant cell;   viii) regenerating the crop plant cell into a whole crop plant;   ix) selecting said crop plant for vegetative herbicide tolerance by application of an effective dose of said herbicide of step iii;   ix) growing said crop plant into a herbicide tolerant crop plant, wherein male tissues are intolerant to said herbicide.   
     
     
         10 . The method of  claim 9  wherein said herbicide is glyphosate. 
     
     
         11 . The method of  claim 10  wherein herbicide tolerance gene is selected from the group consisting of glyphosate resistant EPSP synthases. 
     
     
         12 . A crop plant produced by the methods of any of  claim 2 ,  8 , or  9 . 
     
     
         13 . Progeny of the crops plants of  claim 12 .