Effects of Drought- stress on Protective Enzyme Activity and Membrane Lipid Peroxidation in Leaf of Soybean Flowering-poding Period

The effects of drought- stress on the protective enzyme activity and membrane lipid peroxidation in leaf of soybean flowering-poding period and their relationship with the tolerance to drought were studied with two different drought- tolerant cultivars. The result showed that with the strength of drought- stress, permeability of plasmas membrane and contents of MDA increased gradually, and activities of SOD, POD and CAT rose at first and lowered later. Much lower rate of permeability of plasma membrane and malondialdephyde (MAD) content 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, the activity of POD was higher than those of SOD and of CAT.