Effect Of Exogenous Salicylic Acid On Hydrogen Peroxide Metabolism And Membrane Stability Of Wheat Leaves Under Drought Stresses

The contents of hydrogen peroxide(H202) and the activities of H202scavenging enzymes and the changes of membrane stability (MDA contents , the cytomembrarie permeability) and drought resistance of wheat ( configuration of root, relative water content , the rate of net photosynthesis , the capacity of resisting water loss) were studied in wheat leaves sprayed different concentration salicylic acid (SA)and water(control) respectively under drought stress.The results indicated that the wheat leaves treated with SA of about O.2mmollL showed higher activities of catalase(CAT) and ascorbate peroxidase(APX), slower accumulate rate of H202, lower malondialdehyde(MDA) content and cytomembrane permeability(p), higher relative water content (RWC), stronger capacity resist water loss , as well as higher rate of net photosynthesis and more rapid recover after rewatering in intact wheat leaves during drought stress .As a result of all these beneficial factors, the membrane stability and the ability to maintain water and resist drought were enhanced in wheat leaves treated with appropriate concentration SA under drought stress.