Study on the Effect of Rare Earth La~(3+) and its Complex La(POA)_3 on Mung Bean Seedling under Pb~(2+) Stress

Ecophysiological effect of La3+ and its complex La(POA)3(HPOA=phonoxyactive acid) on Mung bean seedling under Pb2+ stress were studied through hydroponic experiment.The results showed that rare earth and its complex had obvious detoxication to plumbum.When Mung bean seedling was treated with single 10 mg/L Pb2+ for 4 and 8 days,the content of chlorophyll and soluble protein decreased,the content of praline and MDA increased.When different concentrations(15～50 mg/L) of La3+ or La(POA)3 were added,the degradation of chlorophyll and protein was alleviated,and the accumulation of MDA was reduced in comparison with single Pb2+ treatment,but the higher the La3+ or La(POA)3 concentration,the worse the relieved action,and with the effect time passed,the catabatic operation of La(POA)3 was better than La3+.So the optimum dose of La3+ or La(POA)3 to relieve Pb2+ stress in Mung Bean was ranged from 15～50 mg/L.