Effects of Sulfate Application on Inhibiting Accumulation and Alleviating Toxicity of Arsenic in Panax notoginseng Grown in Arsenic-Polluted Soil

摘要

Panax notoginseng (P. notoginseng) is a well-known traditional Chinese medicinal herb. Due to elevated arsenic (As) levels in some planting area, P. notoginseng and its derivatives are contaminated, and the As concentration in these products exceeds the standard limit (As concentration < 2 mg/kg). In this study, the effects of sulfate (S) application on As uptake and the physicological response of P. notoginseng were investigated in a pot-culture experiment. The results showed that the As concentration in the roots was significantly decreased by a maximum of 64.9 % in response to the application of 75 mg/kg S. The proportion of methylated arsenic, which is less toxic, in the roots was increased by 263.4 %. Moreover, the application of S alleviated the oxidative damage due to As stress, and the activities of superoxide dismutase (SOD) and peroxidase (POD) were improved by 26.2 and 29.4 %, respectively. Finally, the total saponin content in the roots increased by 26.0 % in response to a supply of 50 mg/kg S. These findings implied that the application of S fertilizer could effectively reduce As accumulation in P. notoginseng and promote the formation of pharmaceutical components.