Sun Dan, Zeng Jiahui, Xu Qiuchen, Wang Mingyun, Shentu Xuping
Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Science, China Jiliang University, Hangzhou 310018, China.
Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Science, China Jiliang University, Hangzhou 310018, China.
Pestic Biochem Physiol. 2024 Dec;206:106199. doi: 10.1016/j.pestbp.2024.106199. Epub 2024 Nov 1.
The brown planthopper (BPH), Nilaparvata lugens Stål, is a notorious pest that infests rice across Asia. The rapid evolution of chemical pesticide resistance in BPH poses an ongoing threat to agriculture and human health. Currently, pymetrozine has emerged as a viable alternative to imidacloprid for managing N. lugens. The detoxification of insecticides in insects includes three major metabolic gene families: cytochrome P450 monooxygenases (P450s), glutathione S-transferases (GSTs), and carboxylesterases (CarEs). In this study, highly resistant strains of BPH to pymetrozine (BPH-R: 705-fold) were created from the susceptible BPH strain through continuous multi-selection. The activities of detoxifying enzymes, including P450s, GSTs, and CarEs were measured. Notably, P450s and GSTs exhibited significantly higher activity in the pymetrozine-resistance strain than that of the susceptible BPH strain. Hence, we characterized P450s and GSTs genes in N. lugens and revealed their phylogeny, structure, motif analysis, and chromosome location. Subsequently, the expression profiles of 53 P450s and 11 GSTs genes were quantified, and two crucial detoxifying enzyme genes, NlCYP301B1 and NlGSTm2, were identified as being involved in pymetrozine resistance. Furthermore, RNA interference (RNAi)-mediated silencing of NlCYP301B1 and NlGSTm2 gene expression significantly increased larval mortality of BPH in response to pymetrozine. To our knowledge, enhancing the activity of key detoxification enzymes to resist insecticides represents a widespread and vital defense mechanism in insects.
褐飞虱（Nilaparvata lugens Stål）是一种臭名昭著的害虫，在亚洲各地危害水稻。褐飞虱对化学杀虫剂抗性的快速进化对农业和人类健康构成持续威胁。目前，吡蚜酮已成为防治褐飞虱的一种可行替代药剂，可替代吡虫啉。昆虫体内杀虫剂的解毒作用包括三个主要的代谢基因家族：细胞色素P450单加氧酶（P450s）、谷胱甘肽S-转移酶（GSTs）和羧酸酯酶（CarEs）。在本研究中，通过连续多次筛选，从敏感褐飞虱品系培育出了对吡蚜酮具有高抗性的褐飞虱品系（BPH-R：705倍）。测定了解毒酶（包括P450s、GSTs和CarEs）的活性。值得注意的是，P450s和GSTs在吡蚜酮抗性品系中的活性显著高于敏感褐飞虱品系。因此，我们对褐飞虱中的P450s和GSTs基因进行了表征，并揭示了它们的系统发育、结构、基序分析和染色体定位。随后，对53个P450s基因和11个GSTs基因的表达谱进行了定量分析，并鉴定出两个关键解毒酶基因NlCYP301B1和NlGSTm2与吡蚜酮抗性有关。此外，RNA干扰（RNAi）介导的NlCYP301B1和NlGSTm2基因表达沉默显著提高了褐飞虱幼虫对吡蚜酮的死亡率。据我们所知，增强关键解毒酶的活性以抵抗杀虫剂是昆虫中一种广泛且重要的防御机制。
