Effects of salicylic acid on the anti-oxidant enzymes reactivity of cowpea seedlings under drought stress

The effects of exogenous salicylic acid (SA) on activity of anti-oxidative enzymes in leaves of cowpea (Vigna sinenesis L.) seedlings under drought stress were studied. The results showed that activity of anti-oxygenase and relative water content in leaves of cowpea was gradually decreased under drought stress after pre-treatment with SA and H2O, along with extension of the stress. But after 24 h, water content pretreated by SA was higher than by H2O. In the subsequent progress of stress, the activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) pretreated by SA was higher than by H2O. The isozymes made up of CAT, POD and SOD from leaves of cowpea were analyzed by non-denatured polyacrylamide gel electrophoresis and the results showed that the isozymes of SOD and POD were changed in bands pattern excluding CAT. Therefore,these results indicated SA enhanced the activity of anti-oxidative enzymes in leaves of the cowpea seedlings and strengthened the tolerance of cowpea seedlings against drought stress.