Of Cd Toxic Effects On Mung Bean And Induced Proline Accumulation

Solution cultures and pot experiment were conducted to investigate the biological effects of cadmium (Cd) toxicity on the growth of mung bean (Phaseolus aures Poxb. Cv VC-3762), the uptake of nutriues, the activity changes of superoxide disutase (S0D)~. peroxidase (POD), autoxidation rate of tissue and accumulation of proline. Results showed that Cd inhibited the growth of mung bean seedlings. The concentrations of chllorophyll and chlorophyll a/b concentration ratio gradually decreased with increasing Cd supply in solution and with treatment time. Treatment with Cd decreased the concentrations of Ca, P, Zn and Mn in the shoots, and increased Fe concentration in the shoots. The activities of peroxidase (POD) and superoxide dismutase (SOD) increased with increasing Cd in the leaves and roots. The leaves of mung bean had higher activity of SOD than the roots. But, the activities of POD were higher in the roots than in the leaves. Leaf proline concentrations increased significantly in response to incresing Cd concentrations from 0 to 20 uniolL扖d in the solution. Compared to the control, Cd treatments increased lipid peroxidation rate of leaves and roots. In all treatments, leaves of mung bean seedlings had greater proline concentration and had lower the antoxidation rate of tissue than the roots. The Cd-induced accumulation of proline was more pronounced under continuous light condition than under the continuous dark and light/darkness conditions. There was a close positive correlation between the concentrations of free peoline 46 and rates of tissue autoxidation.