College of Forest Resources and Environment, Nanjing Forestry University, Nanjing, 210037, China.
Ecotoxicology. 2012 Nov;21(8):2297-305. doi: 10.1007/s10646-012-0986-0. Epub 2012 Sep 14.
Glyphosate (GPS) is a wildly-used pesticide throughout the world. It affects metal behaviors in soil-water system as its functional groups such as amine, carboxylate and phosphonate can react with metal ions to form metal complexes. The reaction will result in the decreasing of heavy metal bioavailability. A laboratory experiment was conducted to investigate the interactions between GPS and copper (Cu) on the acute toxicity of soil invertebrate earthworm (Eisenia fetida), which was exposed to aqueous solutions for 48 h with different mixing concentrations of Cu and GPS (technical-grade Gly acid). The mortality rates, Cu uptake by earthworm, and some biomarkers such as superoxide dismutase (SOD) activity, glutathione (GSH) content, and acetylcholinesterase (AchE) activity were measured. The mortality rates and whole-worm metal burdens increased significantly with the increasing Cu concentration in solution. However, toxicity of GPS to earthworms was not observed in this study. Furthermore, the presence of GPS could significantly reduce the acute toxicity of Cu to earthworms. The mortality rates decreased sharply and the uptake of Cu was nearly halted in the presence of GPS. In addition, the SOD activity, GSH content, and AchE activity almost declined to the levels of the control. These results demonstrate that GPS could control the toxicity as well as the bioavailability of heavy metals in soil solutions where both GPS and heavy metals often coexist.
草甘膦（GPS）是一种在全世界广泛使用的农药。它的胺基、羧基和膦酸基等官能团可以与金属离子反应形成金属配合物，从而影响水土体系中的金属行为，导致重金属生物有效性降低。本实验室实验研究了草甘膦（工业级甘氨酸）与铜（Cu）在急性暴露于不同混合浓度 Cu 和 GPS 的水溶液 48 小时后对土壤无脊椎动物蚯蚓（赤子爱胜蚓）的相互作用，测量了死亡率、蚯蚓体内铜的吸收量以及超氧化物歧化酶（SOD）活性、谷胱甘肽（GSH）含量和乙酰胆碱酯酶（AchE）活性等一些生物标志物。死亡率和全虫金属负荷随着溶液中 Cu 浓度的增加而显著增加。然而，在本研究中未观察到草甘膦对蚯蚓的毒性。此外，GPS 的存在可显著降低 Cu 对蚯蚓的急性毒性。GPS 的存在使死亡率急剧下降，Cu 的吸收几乎停止。此外，SOD 活性、GSH 含量和 AchE 活性几乎下降到对照水平。这些结果表明，GPS 可以控制重金属在水土体系中的毒性和生物有效性，因为 GPS 和重金属通常同时存在。
