Methods of modulating stomata conductance and plant expression constructs for executing same

Abstract

Plant expression construct are provided. According to an embodiment, the plant expression construct comprises a nucleic acid sequence encoding a hexokinase under a transcriptional control of a guard cell-specific cis-acting regulatory element. Also provided are methods of using the constructs and transgenic plants, plant cells and plant parts expressing same.

1 . A plant expression construct comprising a nucleic acid sequence encoding a hexokinase under a transcriptional control of a guard cell-specific cis-acting regulatory element. 
     
     
         2 . A plant expression construct comprising a nucleic acid sequence encoding a nucleic acid agent for silencing expression of a hexokinase, wherein expression of said nucleic acid agent is under a transcriptional control of a guard cell-specific cis-acting regulatory element. 
     
     
         3 - 4 . (canceled) 
     
     
         5 . The plant expression construct of  claim 1 , wherein said guard cell-specific cis-acting regulatory element is a guard-cell specific promoter. 
     
     
         6 . The plant expression construct of  claim 5 , wherein said guard-cell specific promoter is KST1 promoter. 
     
     
         7 . A method of regulating plant stomata conductance, the method comprising modulating in the plant the level and/or activity of a hexokinase in a guard cell specific manner, thereby regulating plant conductance. 
     
     
         8 . The method of  claim 7 , wherein said modulating is upregulating. 
     
     
         9 . The method of  claim 8 , wherein said upregulating is effected by introducing the nucleic acid construct comprising a nucleic acid sequence encoding a hexokinase under a transcriptional control of a guard cell-specific cis-acting regulatory element into the plant. 
     
     
         10 . The method of  claim 7 , wherein said modulating is downregulating. 
     
     
         11 . The method of  claim 9 , wherein said downregulating is effected by introducing into the plant a nucleic acid silencing agent under a transcriptional control of a guard cell-specific cis-acting regulatory element. 
     
     
         12 . A method of decreasing plant stomata conductance, the method comprising introducing into a cell of a plant the nucleic acid construct of  claim 1 , thereby decreasing the stomata conductance of the plant. 
     
     
         13 . A method of increasing water use efficiency of a plant, the method comprising introducing into a cell of the plant the nucleic acid construct of  claim 1 , thereby increasing water use efficiency of the plant. 
     
     
         14 . A method of increasing tolerance of a plant to drought, salinity or temperature stress, the method comprising introducing into a cell of the plant the nucleic acid construct of  claim 1 , thereby increasing tolerance of the plant to drought, salinity or temperature stress. 
     
     
         15 . A method of increasing biomass, vigor or yield of a plant, the method comprising introducing into a cell of the plant the nucleic acid construct of  claim 1 , thereby increasing the biomass, vigor or yield of the plant. 
     
     
         16 . A method of increasing tolerance of a plant to biotic stress, the method comprising introducing into a cell of the plant the nucleic acid construct of  claim 1 , thereby increasing tolerance of the plant to biotic stress. 
     
     
         17 . A transgenic plant or a part thereof comprising the plant expression construct of  claim 1 . 
     
     
         18 - 19 . (canceled) 
     
     
         20 . The part of the transgenic plant of  claim 17 , being a seed. 
     
     
         21 . The part of the transgenic plant of  claim 17 , being a leaf. 
     
     
         22 . The part of the transgenic plant of  claim 17 , wherein said seed is a hybrid seed. 
     
     
         23 . The method of  claim 12 , further comprising growing the plant under water deficient conditions or under salinity. 
     
     
         24 . (canceled)