Pesticide risk assessment at the molecular level using honey bee cytochrome P450 enzymes: A complementary approach
Pesticide risk assessment at the molecular level using honey bee cytochrome P450 enzymes: A complementary approach
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DOI：
10.1016/j.envint.2020.106372
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发表时间：
2021-01-05
影响因子：
11.8
通讯作者：
Nauen, Ralf
中科院分区：
文献类型：
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作者：
Haas, Julian;Nauen, Ralf
蜜蜂（Apis mellifera）的一级农药风险评估主要基于急性和慢性暴露后的标准化实验室毒性生物测定。最近对蜜蜂细胞色素P450单加氧酶（P450）的研究发现，CYP 9 Q3是介导类烟碱杀虫剂选择性的分子决定因素，并解释了为什么某些类烟碱如噻虫啉显示出比其他类（如吡虫啉）低1000倍以上的急性毒性。在此，利用基于荧光的高通量体外测定在分子水平上对该知识进行机械风险评估，预测不同杀虫化学型（包括唑类杀真菌剂）与重组表达的蜜蜂CYP 9 Q酶（已知代谢噻虫啉、啶虫脒和tau-氟胺氰菊酯）的相互作用。一些唑类杀真菌剂与某些杀虫剂（包括烟碱类和拟除虫菊酯）组合显示出协同增效作用，而其他杀真菌剂（如丙硫菌唑）则没有协同增效作用。我们证明，唑类化合物的生化CYP 9 Q2/CYP 9 Q3抑制数据显示出与其在生物体水平上的协同潜力显著相关，甚至可以解释在田间条件下观察到的罐混合物的联合毒性效应。我们的新的毒理基因组学为基础的方法，旨在补充现有的农药风险评估方法与前所未有的筛选能力，通过利用蜜蜂P450酶已知赋予农药的选择性，以生物化学解决生态毒理学关注的问题。
Honey bee (Apis mellifera) first-tier pesticide risk assessment is largely based on standardized laboratory toxicity bioassays after both acute and chronic exposure. Recent research on honey bee cytochrome P450 monooxygenases (P450s) uncovered CYP9Q3 as the molecular determinant mediating neonicotinoid insecticide selectivity and explaining why certain neonicotinoids such as thiacloprid show > 1000-fold lower acute toxicity than others (e.g. imidacloprid). Here this knowledge is leveraged for mechanistic risk assessment at the molecular level using a fluorescence-based high-throughput in vitro assay, predicting the interaction of diverse pesticidal chemotypes, including azole fungicides, with recombinantly expressed honey bee CYP9Q enzymes, known to metabolize thiacloprid, acetamiprid and tau-fluvalinate. Some azole fungicides were shown to be synergistic in combination with certain insecticides, including neonicotinoids and pyrethroids, whereas others such as prothioconazole were not. We demonstrate that biochemical CYP9Q2/CYP9Q3 inhibition data of azoles revealed a striking correlation with their synergistic potential at the organismal level, and even allow to explain combined toxicity effects observed for tank mixtures under field conditions. Our novel toxicogenomics-based approach is designed to complement existing methods for pesticide risk assessment with unprecedented screening capacity, by utilizing honey bee P450 enzymes known to confer pesticide selectivity, in order to biochemically address issues of ecotoxicological concern.