Effect of Drought Stress Simulated by PEG6000 on Malondialdehyde Content and Activities of Protective Enzymes in Barley Seedlings

【Objective】The aim of this paper was to study the effect of drought stress on malondialdehyde content and activities of protective enzymes in barley seedlings.【Method】Malondialdehyde contents and the activities of superoxide dismutase,peroxidase,and catalase in shoot and root of 4 barley varieties under drought stress simulated by PEG6000 were determined.【Result】The malondialdehyde contents in shoot and root of 4 tested varieties increased with the prolongation of drought stress time.The superoxide dismutase and peroxidase activities in shoot rose up firstly and then declined with the prolongation of drought stress time. There were differences between root and shoot protective enzyme activities.The 4 varieties also differed in the activities of superoxide dismutase,peroxidase and catalase.The activities of superoxide dismutase and peroxidase in drought-resistant varieties(Tevcel and Aiganzao) increased more quickly than that in drought-sensitive varieties(Guangmai 7 and Cmebc).The activities of three enzymes decreased with the prolongation of drought stress time.Moreover,the activities of the three enzymes of the drought-sensitive varieties(Guangmai 7 and Cmebc) decreased sharply.【Conclusion】Under drought stress,the activities of superoxide dismutase,peroxidase and catalase and malondialdehyde content can be used as the screening indicator in barley drought resistance.