Silicon-induced alleviation of cadmium toxicity in hyperaccumulator Solanum nigrum L

Silicon-induced amelioration of cadmium toxicity in the cadmium-hyperaccumulator Solanum nigrum L was investigated. Four-week-old seedlings of S. nigrum exposed to 200 μmol/L Cd with or without 1 mmol/L Si for 4 days. Malondialdehyde and electrolyte leakage in leaves were dramatically enhanced in single Cd treatment, and photosynthesis and biomass were seriously depressed. In comparison with the Cd treatment alone, lipid peroxidation and electrolyte leakage were significantly reduced in Cd plus Si treatment; shoot height, root length and dry weight were strongly increased; in addition, Cd concentrations in seedlings were decreased, while Cd translocation from root to shoot was remarkably enhanced. Furthermore, the activities of superoxide dismutase, peroxidases, and catalase in Cd plus Si treatment were significantly lower than that in Cd treatment alone, this decrease might be attributed to the reduction of Cd concentrations and Cd-induced oxidative damage by Si application.