[Effects of Fe-Cd interaction on the lipid peroxidation and antioxidative enzyme activities of rice]

Taking rice variety Shennong 265 as test material, a hydroponic experiment was conducted to investigate the effects of Fe (0, 0.1, 0.25 and 0.5 mmol Fe2+ x L(-1)) and Cd (0, 0.1 and 1.0 umol Cd2+ x L(-1)) on the lipid peroxidation and antioxidative enzyme activities of rice plant. When the Fe was supplied alone, the shoot and root dry mass decreased significantly, but this phenomenon would not occur when the Cd was applied simultaneously. Applying Cd alone decreased the root malondialdehyde (MDA) and soluble protein contents, but applying Fe simultaneously alleviated the negative effects of Cd. Applying Fe decreased the Cd concentrations in shoots and roots, whereas applying Cd decreased the shoot and root Fe concentrations, indicating an obvious antagonistic interaction between Fe and Cd. The interaction of high concentration (1.0 micromol x L(-1)) Cd with Fe increased the root MDA and soluble protein contents, and decreased the root superoxide dismutase (SOD) and catalase (CAT) activities. These results indicated that applying definite amount of exogenous Fe could decrease the Cd accumulation in rice under low Cd stress, whereas high Cd stress would decrease the Fe absorption by rice and induce the lipid peroxidation in rice plant.