Department of Entomology, China Agricultural University, Beijing 100193, China.
Department of Entomology, China Agricultural University, Beijing 100193, China.
Int J Biol Macromol. 2023 Mar 1;230:123389. doi: 10.1016/j.ijbiomac.2023.123389. Epub 2023 Jan 24.
The frequent and extensive use of insecticides leads to the evolution of insecticide resistance, which has become one of the constraints on global agricultural production. Avermectins are microbial-derived insecticides that target a wide number of insect pests, including the diamondback moth Plutella xylostella, an important global pest of brassicaceous vegetables. However, field populations of P. xylostella have evolved serious resistance to avermectins, including abamectin, thereby threatening the efficiency of these insecticides. In this study, a novel valine to isoleucine mutation (V263I) was identified in the glutamate-gated chloride channel (GluCl) of field P. xylostella populations, which showed different levels of resistance to abamectin. Electrophysiological analysis revealed that the V263I mutation significantly reduced the sensitivity of PxGluCl to abamectin by 6.9-fold. Genome-modified Drosophila melanogaster carrying the V263I mutation exhibited 27.1-fold resistance to abamectin. Then, a knockin strain (V263I-KI) of P. xylostella expressing the homozygous V263I mutation was successfully constructed using the CRISPR/Cas9. The V263I-KI had high resistance to abamectin (106.3-fold), but significantly reduced fecundity. In this study, the function of V263I mutation in PxGluCl was verified for the first time. These findings provide a more comprehensive understanding of abamectin resistance mechanisms and lay the foundation for providing a new molecular detection method for abamectin resistance monitoring.
杀虫剂的频繁和广泛使用导致了杀虫剂抗性的进化，这已成为全球农业生产的制约因素之一。阿维菌素是微生物衍生的杀虫剂，针对包括小菜蛾 Plutella xylostella 在内的广泛数量的昆虫害虫，小菜蛾是十字花科蔬菜的重要全球性害虫。然而，小菜蛾田间种群已经对阿维菌素产生了严重的抗性，包括阿维菌素，从而威胁到这些杀虫剂的效率。在这项研究中，在小菜蛾田间种群的谷氨酸门控氯离子通道（GluCl）中鉴定出一种新的缬氨酸到异亮氨酸突变（V263I），该突变对阿维菌素表现出不同程度的抗性。电生理分析表明，V263I 突变使 PxGluCl 对阿维菌素的敏感性降低了 6.9 倍。携带 V263I 突变的基因组修饰果蝇 Drosophila melanogaster 对阿维菌素表现出 27.1 倍的抗性。然后，利用 CRISPR/Cas9 成功构建了表达纯合 V263I 突变的小菜蛾敲入品系（V263I-KI）。V263I-KI 对阿维菌素具有高抗性（106.3 倍），但显著降低了繁殖力。在这项研究中，首次验证了 V263I 突变在 PxGluCl 中的功能。这些发现为阿维菌素抗性机制提供了更全面的理解，并为阿维菌素抗性监测提供新的分子检测方法奠定了基础。
