丁氟螨酯在苹果种植环境中立体选择性残留行为与毒性差异机制研究

Cyflumetofen, a novel class of chiral acaricide, has greatly increased used for the control of mites in apple orchards. However, the researches only stay in the racemic compounds, lack of research on their selective degradation behavior and enantioselective toxicity, which posed a serious threat to our human health and environment safety. The previous studies proved that chiral cyflumetofen have significant enantioselective toxicity to non-target organism hoverfly. Consequently, in this study, the single enantiomers of cyflumetofen were studied the environmental fate in apples and soils, find out the regularity of the residue, accumulation, migration, and transformation of the enantiomers of cyflumetofen. To make sure the critical control points of the safe use of cyflumetofen, the main degradation products and metabolic were studied to disclose by high performance liquid chromatography-mass spectrometry. Meanwhile, the enantioselective toxicology on target (mite) and non-target organism (predatory mites) between the enantiomers was studied based on the molecular biology method. Furthermore, proteomics and metabolomics will be used to study the interference of target and non-target organism metabolic pathway by different cyflumetofen enantiomers. Based on relational analysis, reveal why the cyflumetofen enantiomers selectively recognize proteins and affect metabolic pathways，It is helpful to provide a data support and theoretical basis for selective of chiral pesticides on the ecological environment risk assessment, and development of new pesticide targets.

丁氟螨酯作为新型手性杀螨剂，近年来在苹果园中施用量剧增，当前丁氟螨酯的研究主要集中在消旋体水平上，其立体选择性环境行为和毒性差异机制尚不清晰，给人类健康和生态环境带来严重安全隐患。前期研究表明，(-)-丁氟螨酯对非靶标生物呈现高毒，说明在毒性方面存在选择性。在此基础上，本项目拟通过研究丁氟螨酯在苹果植株及土壤中选择性环境行为，揭示其对映体水平的残留、积累、迁移及转化规律；利用色谱质谱联用技术定性定量分析降解产物，揭示代谢途径差异和关键影响因子；开展对映体对靶标生物的活性和非靶标生物的毒性差异，明确其高效体和高毒体，揭示丁氟螨酯高毒体和高效体在苹果种植环境中主要行为归趋；基于蛋白质组学和代谢组学方法，研究丁氟螨酯对映体间选择性毒性差异，阐明其选择性结合蛋白及影响代谢的毒性差异机制，为手性农药选择性影响生态环境和新农药靶点开发提供理论依据。

本研究明确了丁氟螨酯喷施对苹果营养及风味品质的影响，发现其可通过干扰氨基酸和脂肪酸两种代谢途径中关键酶的活性对苹果风味产生影响，且与施药浓度呈现一定的相关性；通过种植过程中消解动态研究，进一步明确其在苹果种植过程中未发生显著的选择性降解；通过急性毒性试验，发现丁氟螨酯对映体对靶标生物（捕食螨及红蜘蛛）间选择性毒性差异，且 (+)-CYF毒性大于 (-)-CYF，相同的结果也发生在非靶标生物蜜蜂上；二维电泳结合高分辨率质谱法显示，亚致死剂量CYF处理的蜜蜂中蛋白质差异表达主要与能量代谢、应激反应和蛋白质合成有关，其中雌激素诱导相关的FAM102A蛋白上调也证实了CYF在蜜蜂中的雌激素活性。通过斑马鱼胚胎发育试验、成年斑马鱼生殖毒性试验结合转录组和代谢组测序，初探丁氟螨酯及其降解产物间的差异毒性以及通过生殖轴干扰生殖毒性调控分子机理，发育毒性试验结果表明丁氟螨酯对映体、水解产物和母体之间具有显著的毒性差异；生殖毒性试验结果表明CYF和B-1对HPG轴的影响抑制了斑马鱼配子的成熟和繁殖行为，降低了生殖能力，并且CYF和B-1对斑马鱼的影响存在大量差异表达基因，说明CYF和B-1对斑马鱼HPG轴存在多靶点影响，并改变相关信号通路中关键基因的表达水平引起生殖毒性，从而抑制了斑马鱼的生殖能力。总之，本研究为丁氟螨酯、丁氟螨酯对映体以及降解产物在农业系统中的使用提供了更全面的安全性评价。