Key Laboratory of Plant Protection Resources & Pest Management of the Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling, China.
Pest Manag Sci. 2023 Jul;79(7):2456-2468. doi: 10.1002/ps.7415. Epub 2023 Mar 9.
Insecticide resistance continuously poses a threat to agricultural production. Chemosensory protein-mediated resistance is a new mechanism of insecticide resistance discovered in recent years. In-depth research on resistance mediated by chemosensory proteins (CSPs) provides new insight into aid insecticide resistance management.
Chemosensory protein 1 in Plutella xylostella (PxCSP1) was overexpressed in the two indoxacarb-resistant field populations and PxCSP1 has a high affinity with indoxacarb. PxCSP1 was upregulated when exposed to indoxacarb and the knockdown of this gene elevated sensitivity to indoxacarb, which demonstrate that PxCSP1 is involved in the indoxacarb resistance. Considering that CSPs may confer resistance in insects via binding or sequestering, we explored the binding mechanism of indoxacarb in PxCSP1-mediated resistance. Using molecular dynamics simulations and site-directed mutation, we found that indoxacarb forms a solid complex with PxCSP1 mainly through van der Waals interactions and electrostatic interactions. Between these, the electrostatic interaction provided by the Lys100 side chain in PxCSP1, and especially the hydrogen bonding between the NZ atom and the O of the carbamoyl carbonyl group of indoxacarb, are the key factors for the high affinity of PxCSP1 to indoxacarb.
The overexpression of PxCPS1 and its high affinity to indoxacarb is partially responsible for indoxacarb resistance in P. xylostella. Modification of indoxacarb's carbamoyl group has the potential to alleviate indoxacarb resistance in P. xylostella. These findings will contribute to solving chemosensory protein-mediated indoxacarb resistance and provide a better understanding of the insecticide resistance mechanism. © 2023 Society of Chemical Industry.
杀虫剂抗性不断对农业生产构成威胁。近年来发现的化学感受蛋白介导的抗性是一种新的杀虫剂抗性机制。深入研究化学感受蛋白（CSPs）介导的抗性为辅助杀虫剂抗性管理提供了新的见解。
小菜蛾（P. xylostella）中的化学感受蛋白 1（PxCSP1）在两种茚虫威抗性田间种群中过表达，并且 PxCSP1 与茚虫威具有高亲和力。暴露于茚虫威时 PxCSP1 上调，该基因的敲低提高了对茚虫威的敏感性，这表明 PxCSP1 参与了茚虫威抗性。考虑到 CSPs 可能通过结合或隔离赋予昆虫抗性，我们探索了 PxCSP1 介导的抗性中茚虫威的结合机制。通过分子动力学模拟和定点突变，我们发现茚虫威与 PxCSP1 主要通过范德华相互作用和静电相互作用形成稳定的复合物。在这些相互作用中，PxCSP1 中 Lys100 侧链提供的静电相互作用，特别是茚虫威的 NZ 原子与酰胺羰基氧原子之间的氢键，是 PxCSP1 与茚虫威高亲和力的关键因素。
PxCPS1 的过表达及其对茚虫威的高亲和力部分导致了小菜蛾对茚虫威的抗性。对茚虫威的酰胺基进行修饰有可能减轻小菜蛾对茚虫威的抗性。这些发现将有助于解决化学感受蛋白介导的茚虫威抗性，并更好地理解杀虫剂抗性机制。 © 2023 化学工业协会。
