Effects of Drought Stress on Protective Enzymes Activities and Membrane Lipid Peroxidation in Leaves of Soybean Seedlings

The effects of drought stress on the protective enzymes activities and membrane lipid peroxidation in leaves of soybean seedlings and their relationship with drought tolerance were studied with two different drought-tolerant cultivars.The result showed that with the increase of drought stress,permeability of plasmas membrane and contents of MDA increased gradually,and activities of SOD?POD?CAT rose at first and lowered later.Much lower the rate of permeability of plasma membrane and malondialdephyde(MAD) contents were appeared in drought-tolerant cultivars than those in drought-sensitive cultivars under drought stress.And the drought-tolerant ones had higher SOD?CAT and POD activities.In severe drought conditions,activities of POD were higher than those of SOD and CAT.