Identification of a New Potential Cd-Accumulator Pterocypsela indica (L.) Shih.

Three experiments were conducted to investigate the Cd tolerance and accumulation ability of a forage grass, Pterocypsela indica. P. indica accumulated 31.40 and 69.68 mg/kg Cd in roots and shoots, respectively, and plant biomass was unaffected by soil Cd as high as 50 mg/kg. Cd pollution obviously increased the Cd content of the cell wall fraction and decreased that of the soluble fraction in plant roots, but had little effect on the subcellular Cd content in plant shoots. When soil was co-contaminated by 2.29 mg/kg Cd, 526.83 mg/kg Zn, and 595.38 mg/kg Pb, P. indica accumulated 61.63 mg/kg Cd, 4261.00 mg/kg Zn, and 75.27 mg/kg Pb in plant shoots. The results indicated that P. indica mainly detoxified Cd stress by improving the fixation of Cd on the cell wall of plant roots rather than shoots. P. indica is a potential Cd accumulator that has a high phytoremediation efficiency in Cd-Zn-contaminated soil.