State key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
J Environ Sci (China). 2011;23(4):601-6. doi: 10.1016/s1001-0742(10)60454-8.
This study investigates arsenic (As) accumulation and tolerance of duckweed Spirodela polyrhiza L. and its potential for As phytofiltration. S. polyrhiza was able to survive in high concentration of As(V) solution. The EC50 values (+/- SE) based on the external As(V) were (181.66 +/- 20.12) micromol/L. It accumulated (999 +/- 95) mg As/kg dw when exposed in 320 micromol/L As(V) solution for one week, and was able to take up appropriately 400 mg As/kg dw in tissues without a significant biomass loss. The EC50 values (the effective concentration of As(V) in the nutrient solution that caused a 50% inhibition on biomass production) was (866 +/- 68) mg/kg dw for the tissues, indicating that S. polyrhiza had a high capability of As accumulation and tolerance. The uptake kinetic parameters Vmax was (55.33 +/- 2.24) nmol/(g dw min) and Km was (0.144 +/- 0.011) mmol/L. Within 72 hr, S. polyrhiza decreased As concentration in the solution from 190 to 113 ng/mL with a removal rate of 41%. The study suggested that this floating aquatic plant has some potential for As phytofiltration in contaminated water bodies or paddy soils.
本研究调查了浮萍（Spirodela polyrhiza L.）对砷（As）的积累和耐受性及其作为砷植物过滤的潜力。浮萍能够在高浓度的砷（V）溶液中存活。基于外部砷（V）的 EC50 值（+/- SE）为（181.66 +/- 20.12）µmol/L。当暴露在 320µmol/L 的砷（V）溶液中一周时，它积累了（999 +/- 95）mg As/kg dw，并且能够在没有明显生物量损失的情况下适当吸收 400mg As/kg dw。组织中的 EC50 值（导致生物量产生 50%抑制的营养溶液中砷（V）的有效浓度）为（866 +/- 68）mg/kg dw，表明浮萍具有很强的砷积累和耐受性。摄取动力学参数 Vmax 为（55.33 +/- 2.24）nmol/（g dw min），Km 为（0.144 +/- 0.011）mmol/L。在 72 小时内，浮萍将溶液中的砷浓度从 190 降至 113ng/mL，去除率为 41%。研究表明，这种漂浮水生植物在受污染的水体或稻田中具有一定的砷植物过滤潜力。
