Excessive sulfur supply reduces cadmium accumulation in brown rice (Oryza sativa L.)

Human activities have resulted in cadmium (Cd) and sulfur (S) accumulation in paddy soils in parts of southern China. A combined soil–sand pot experiment was conducted to investigate the influence of excessive S supply on iron plaque formation and Cd accumulation in rice plants, using two Cd levels (0, 1.5 mg kg−1) combined with three S concentrations (0, 60, 120 mg kg−1). The results showed that excessive S supply significantly decreased Cd accumulation in brown rice due to the decrease of Cd availability and the increase of glutathione in rice leaves. But excessive S supply obviously increased Cd accumulation in roots due to the decrease of iron plaque formation on the root surface of rice. Therefore, excessive S supply may result in loss of rice yield, but it could effectively reduce Cd accumulation in brown rice exposed to Cd contaminated soils.