Effects of drought stress on protective enzyme activities and lipid peroxidation in two maize cultivars.

Response of antioxidative defense system to drought stress was studied in two cultivars of maize differing in sensitivity to drought. The six-days-old seedlings were transferred in to different concentrations of polyethyleneglycol (PEG) 6000 as drought stress treatment. After 24 h treatment with PEG 6000 an increase was observed in protective enzymes, MDA content and electrolyte leakage. Under drought stress the activities of protective enzymes in roots and shoots increased sharply. This increase in 704 variety was higher than 301 variety. The protective enzyme activities in roots were lower than those in shoots. The content of malondialdehyde (MDA) increased according to severity of water stress. The content of MDA in roots was lower than in shoots. The electrolyte leakage increased greatly in drought stress, too. Increase of MDA content and electrolyte leakage in 704 variety were higher than 301 variety.