Effects of soil acidification on the toxicity of organophosphorus pesticide on Eisenia fetida and its mechanism
Effects of soil acidification on the toxicity of organophosphorus pesticide on Eisenia fetida and its mechanism
复制标题
土壤酸化对有机磷农药对赤爱胜蚓毒性的影响及其机制
DOI：
10.1016/j.jhazmat.2018.04.036
复制
发表时间：
2018-10-05
影响因子：
13.6
通讯作者：
Huang, Xiangfeng
中科院分区：
文献类型：
--
作者：
Zou, Xiaoming;Xiao, Xiaoyu;Huang, Xiangfeng
有机磷农药在农业害虫防治中得到了广泛的应用。土壤酸化是集约化农业系统土壤中的主要问题，特别是在具有低pH缓冲能力的红壤中。然而，土壤酸化对农药毒性的影响尚不清楚。本研究以大肠杆菌E.通过使用酸化土壤（pH = 5.5、4.3和3.1），在个体（14天致死试验）和生化水平（抗氧化防御酶）上测定fetida。结果表明，随着土壤pH值的降低，有机磷农药的毒性略有增加。基于有机磷农药的毒性机理，采用偏最小二乘回归（PLS）方法，建立了有机磷农药的定量构效关系（QSAR）模型。该模型表明，生物有效性和毒理动力学是土壤酸化影响有机磷毒性的关键因素。结果表明，有机磷农药的生物有效性与其水解和生物降解特性密切相关，而土壤酸化对有机磷农药毒性动力学的影响主要是由乙酰胆碱酯酶（AchE）与有机磷农药之间的相互作用引起的。研究结果有助于加深对土壤酸化对农药毒性的影响及其机理的认识。
Organophosphorus pesticides (OPs) have been widely used to control agricultural insects. Soil acidification is a major problem in soil of intensive agricultural systems, especially in red soil with a low pH buffer capacity. However, the effects of soil acidification on the toxicity of pesticides are still unclear. In the present study, the toxicity of three OPs on E. fetida was determined at individual (14-day lethal test) and biochemical levels (antioxidative defence enzymes) by using acidified soils (pH = 5.5, 4.3 and 3.1). The results showed that the toxicity of tested OPs was slightly increased with the decrease of soil pH. To interpret the phenomena, an optimum Quantitative Structure Activity Relationship (QSAR) model was developed based on the toxicity mechanism and the partial least squares regression (PLS) method. The model indicated bioavailability and toxicodynamics are key factors of soil acidification affecting the toxicity of the OPs. Further results revealed the bioavailability of the OPs was strongly related to their hydrolysis and biodegradation character, whereas the effects of soil acidification on toxicodynamics were mainly caused by the interaction between the acetylcholinesterase (AchE) and the OPs. Results will increase understanding of the effects of soil acidification on the toxicity of pesticides and its mechanism.