Effects of salicylic acid pretreatment on some physiological processes of maize seedlings under water stress

The effects of the seed soaking with salicylic acid (SA)on the protective enzymes and photosynthesis rate and the water metabolism in maize seedlings under water stress were studied through sand cultivation experiment.The results showed that,contrasting to the control of seed soaking with water stress,SA pretreatment increased significantly the activities of superoxide dismutase(SOD),peroxiidase(POD)and ascorbate peroxidase(APX) in maize seedlings under water stress,but decreased the producing rate of superoxide radical(O -· 2 )markedly,and the membrane lipid peroxidation.SA pretreatment also increased the contents of protein,chlorophyll,and chl.a/b ratio of maize leaves,so did the photosynthesis rate.It aslo enhanced the holding ability for water of maize leaves and increased water content per gram of leaf in dry weight.So,it improved the water metabolism.SA pretreament could alleviate the water stress on maize seedlings.