Effect of cadmium stress on growth,physiological characteristics and cadmium enrichment of Pueraria thomsonii Benth.seedlings
[Objective]Agricultural ecology and human health are seriously threatened by cadmium(Cd)pollution.It is of great significance to explore the accumulation effect and physiological mechanism of crops on Cd.[Method]A pueraria(Pueraria thomsonii Benth.)variety gange1 was used to investigate the growth,Cd enrichment characteristics,tolerance and physiological response under Cd stress.A hydroponic experiment was conducted to study the effects of different concentrations of Cd(0,10,25,50 and 100 mg/L)stress on Cd content,peroxidase,catalase,superoxide dismutase,malondialdehyde,soluble sugar and soluble protein content in leaves of P.thomsonii seedlings.[Result]Results showed that Cd stress had a low promotion and high inhibition effect on the growth of P.thomsonii seedlings.The daily growth rate of leaves(leaf length and leaf width)increased first and then decreased with the increase of Cd concentration,and reached the maximum at 25 mg/L concentration.Overall,with the increase of Cd concentration,the peroxidase and superoxide dismutase activity of P.thomsonii leaves showed a trend of"rising,then falling,then rising".The peroxidase activity was significantly increased by 174.90%-200.13%.With the increase of Cd concentration,catalase activity,malondialdehyde and soluble sugar content of P.thomsonii leaves showed a trend of decreasing followed by increasing.With the increase of Cd concentration,soluble protein content of P.thomsonii leaves showed a trend of increasing and then decreasing.The Cd contents in roots and leaves of P.thomsonii increased significantly with the increasing of Cd concentration(P<0.05).The enrichment coefficients of roots and leaves were 24.42-28.36 and 5.24-8.39,respectively.The correlation showed that the Cd contents in the roots and leaves of P.thomsonii seedlings was significantly positively correlated with the Cd content in the test solution(P<0.001).[Conclusion]In conclusion,P.thomsonii is a potential Cd tolerant plant with strong Cd enrichment capacity and mitigates Cd toxicity through antioxidant system adjustment and root sequestration.This study provides a theoretical basis for finding suitable phytoremediation materials.
国家科技期刊平台
NSTL
万方数据
