ACCUMULATION OF SUPEROXIDE RADICAL IN WHEAT LEAVES UNDER CADMIUM STRESS
镉胁迫下小麦叶中超氧阴离子自由基的积累

Germinating seedlings of wheat (Triticum aestivum) were treated with different concentrations of cadmium acetate (0.05, 0.1, 0.3, 0.5 and 1.0 mmol/L. Cd2+ treatment significantly enhanced the accumulations of superoxide radical (O-·2) and malondialdehyde (MDA) in wheat leaves. Under cadmium stress, the activity of superoxide dismutase (EC1.15.1.1) apparently decreased while catalase (EC1.11.1.6) changed insignificantly. Furthermore, the content of sulfhyryl group was lower, and the electrolyte leakage outward leave cells was much high. Our results suggest that effects of Cd2+ on wheat seeding are achieved by excessive accumulation of superoxide radical which results from the degradation of the free radical scavenging system.