Under the soil drought stress,content of MDA,that is the product of lipid peroxidation,and electrolyte leakage in the needles of korean pine( Pinus koraiensis Sieb.et .Zucc) seedlings increased suddenly after 3 days of drought treatment.Autoxidation rate increased in the beginning and after 3 days stress it decreased to the level of that before the stress.Activity of cell defense enzymes SOD,POD and CAT all increased markedly and ASP activity decreased.The results of PEG drought stress are different from...