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Acta Prataculturae Sinica ›› 2016, Vol. 25 ›› Issue (2): 198-204.DOI: 10.11686/cyxb2015158

• Orginal Article • Previous Articles     Next Articles

Physiological response of Chamaecrista rotundifolia to cadmium exposure

HE Li-Xiang, HUANG Yun-Xiang*, HUANG Chu-Yu, LIU Li-Shan, LONG Xiang, LUO Lin   

  1. College of Resource and Environment, Hunan Agricultural University, Changsha 410128, China
  • Received:2015-03-26 Online:2016-02-20 Published:2016-02-20

Abstract: Chamaecrista rotundifolia, introduced from Australia in the 1980s is a leguminous forage widely cultivated in subtropical regions. The effects of cadmium (Cd) exposure on the growth and physiological characteristic of C. rotundifolia were studied at different Cd concentrations (0, 1, 2, 4, 8 mg Cd/kg dry soil) using a pot experiment. When C. rotundifolia was exposed to a Cd concentration of 1-2 mg Cd/kg soil, the protective enzymes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were all produced and C. rotundifolia growth was normal. There was no significant decrease in underground or aboveground biomass, compared with the controls. When C. rotundifolia was exposed to 4 mg Cd/kg soil, SOD activity was reduced, while the content of the oxidative stress marker malondialdehyde (MDA) increased. However, the enzymes POD and CAT were activated. Therefore, there was some alleviation of Cd stress. Although no tissue death was observed, at the Cd concentration of 4.0 mg/kg, the values for underground and above ground biomass were reduced by 59.69% and 63.77%, respectively, compared with the control. When C. rotundifolia was exposed to 8 mg Cd/kg soil, the MDA content increased significantly, the cell protective enzyme system was imbalanced, and all plants were dead when harvested. The synthesis of chlorophyll a, chlorophyll b and carotenoids was inhibited by Cd exposure, and the inhibitory effect increased with increasing Cd concentration. The Cd accumulated mainly in the underground organs of C. rotundifolia, and the translocation factor was only 0.152-0.234. In this experiment were available Cd was added to soil, C. rotundifolia tolerated Cd concentrations below 2.0 mg/kg. C. rotundifolia has potential as a remediation plant to restore soil contaminated with Cd by mining operations in China’s south red soil region.