Methods for modulating plant response to environmentally-induced stress

Abstract

Compounds and methods are described herein that are effective to modulate plant response (e.g., plant susceptibility) to environmentally-induced stress. The compounds and methods described herein advantageously may be used to modulate environmental stress resistance in a wide variety of plants. Environmental stresses include, for example, high light intensity (UV exposure), temperature (e.g., high heat), high soil salinity, and low soil moisture (e.g., drought). As used herein, environmental stresses include any conditions that result in increased generation of reactive oxygen species (ROS) and accumulation of ROS in the plant cells. The compounds described herein that are effective to modulate resistance to the stress prevent, directly or indirectly, or increase phosphorylation of Tyr 248 of the RACK1A protein.

1 . A method for modulating environmental stress resistance in a plant, the method comprising applying to plant material, area of cultivation, or combination thereof an amount of a compound effective to increase Tyr248 phosphorylation of RACK1A in response to the environmental stress. 
     
     
         2 . The method of  claim 1 , wherein the plant material comprises foliage, stem, roots, soil, or a combination thereof. 
     
     
         3 . The method of  claim 1 , wherein the compound is selected from any one of the following: 
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein 
         R 1  is halogen; OH; lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower halo-alkyl comprising C 1  to C 10  halo-alkyl; lower alkoxy comprising C 1  to C 10  alkoxy, preferably a C 1  to C 6  alkoxy, more preferably methoxy; or lower halo-alkoxy, and 
         R 2  is a lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower halo-alkyl comprising C 1  to C 10  halo-alkyl, preferably a C 1  to C 6  halo-alkyl, more preferably a halo-alkyl comprising —CF 3 , —C 2 F 5 , or —C 3 F 7 ; —SH; or —N(R 7 ) x , 
         wherein 
         x is 1 or 2 and 
         R 7  is N, —OH, lower alkyl, lower halo-alkyl, lower alkoxy, lower halo-alkoxy; an aromatic group; —SCH 2 CONR 8 ; —SCH 2 COOR 8 ; or —SCH 2 COR 8 , 
         wherein 
         R 8  is —H, lower alkyl, or lower halo-alkyl; 
       
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein 
         R 1  is a halogen; OH; lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower halo-alkyl comprising C 1  to C 10  halo-alkyl; lower alkoxy comprising C 1  to C 10  alkoxy, preferably a C 1  to C 6  alkoxy, more preferably methoxy; or lower halo-alkoxy; 
         R 2  is a lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower halo-alkyl comprising C 1  to C 10  halo-alkyl, preferably a C 1  to C 6  halo-alkyl, more preferably a halo-alkyl comprising —CF 3 , —C 2 F 5 , or —C 3 F 7 ; —SH; or —N(R 7 ) x , 
         wherein 
         x is 1 or 2; 
         R 6  is lower alkyl or —CF 3 . 
         R 7  is N, —OH, lower alkyl, lower halo-alkyl, lower alkoxy, lower halo-alkoxy; an aromatic group; —SCH 2 CONR 8 ; —SCH 2 COOR 8 ; or —SCH 2 COR 8 ; and 
         R 8  is —H, lower alkyl, or lower halo-alkyl; 
       
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein R 1  is halogen; OH; lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower alkoxy comprising C 1  to C 10  alkoxy, preferably a C 1  to C 6  alkoxy, more preferably methoxy; or lower halo-alkoxy; 
       
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein R 1  is halogen; OH; lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower alkoxy comprising C 1  to C 10  alkoxy, preferably a C 1  to C 6  alkoxy, more preferably methoxy; or lower halo-alkoxy; or 
       
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein R 1  is a halogen, lower alkyl, or lower alkoxy. 
       
     
     
         4 . The method of  claim 1 , wherein the compound is selected from the group consisting of: 
       
         
           
           
               
               
           
         
       
     
     
         5 . The method according to  claim 4 , wherein the compound is 
       
         
           
           
               
               
           
         
         and the environmental stress is high salt content. 
       
     
     
         6 . The method according to  claim 1 , wherein the environmental stress is selected from the group consisting of high light intensity, high soil salinity, low soil moisture, and heat. 
     
     
         7 . The method according to  claim 1 , wherein the compound is diluted in liquid media prior to application to the plant material or area of cultivation. 
     
     
         8 . A method for increasing resistance to environmental stress in a plant, the method comprising applying to plant material, area of cultivation, or combination thereof an amount of a compound effective to decrease Tyr248 phosphorylation of RACK1A in response to the environmental stress. 
     
     
         9 . The method of  claim 8 , wherein the plant material comprises foliage, stem, roots, soil, or a combination thereof. 
     
     
         10 . The method of  claim 8 , wherein the compound is selected from any one of the following: 
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein 
         R 1  is halogen; OH; lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower halo-alkyl comprising C 1  to C 10  halo-alkyl; lower alkoxy comprising C 1  to C 10  alkoxy, preferably a C 1  to C 6  alkoxy, more preferably methoxy; or lower halo-alkoxy, and 
         R 2  is a lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower halo-alkyl comprising C 1  to C 10  halo-alkyl, preferably a C 1  to C 6  halo-alkyl, more preferably a halo-alkyl comprising —CF 3 , —C 2 F 5 , or —C 3 F 7 ; —SH; or —N(R 7 ) x , 
         wherein 
         x is 1 or 2 and 
         R 7  is N, —OH, lower alkyl, lower halo-alkyl, lower alkoxy, lower halo-alkoxy; an aromatic group; —SCH 2 CONR 8 ; —SCH 2 COOR 8 ; or —SCH 2 COR 8 , 
         wherein 
         R 8  is —H, lower alkyl, or lower halo-alkyl; 
       
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein 
         R 1  is a halogen; OH; lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower halo-alkyl comprising C 1  to C 10  halo-alkyl; lower alkoxy comprising C 1  to C 10  alkoxy, preferably a C 1  to C 6  alkoxy, more preferably methoxy; or lower halo-alkoxy; 
         R 2  is a lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower halo-alkyl comprising C 1  to C 10  halo-alkyl, preferably a C 1  to C 6  halo-alkyl, more preferably a halo-alkyl comprising —CF 3 , —C 2 F 5 , or —C 3 F 7 ; —SH; or —N(R 7 ) x , 
         wherein 
         x is 1 or 2; 
         R 6  is lower alkyl or —CF 3 . 
         R 7  is N, —OH, lower alkyl, lower halo-alkyl, lower alkoxy, lower halo-alkoxy; an aromatic group; —SCH 2 CONR 8 ; —SCH 2 COOR 8 ; or —SCH 2 COR 8 ; and 
         R 8  is —H, lower alkyl, or lower halo-alkyl; 
       
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein R 1  is halogen; OH; lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower alkoxy comprising C 1  to C 10  alkoxy, preferably a C 1  to C 6  alkoxy, more preferably methoxy; or lower halo-alkoxy; 
       
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein R 1  is halogen; OH; lower alkyl comprising C 1  to C 10  alkyl, preferably a C 1  to C 6  alkyl; lower alkoxy comprising C 1  to C 10  alkoxy, preferably a C 1  to C 6  alkoxy, more preferably methoxy; or lower halo-alkoxy; or 
       
       
         
           
           
               
               
           
         
         or an agriculturally acceptable salt thereof, 
         wherein R 1  is a halogen, lower alkyl, or lower alkoxy. 
       
     
     
         11 . The method of  claim 8 , wherein the compound is selected from any one of the following: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         12 . The method according to  claim 8 , wherein the environmental stress is selected from the group consisting of high light intensity, high soil salinity, low soil moisture, and heat. 
     
     
         13 . The method according to  claim 8 , wherein the compound is diluted in liquid media prior to application to the plant material or area of cultivation.