Lu Kai, Wang Ying, Chen Xia, Zhang Zhichao, Li Yue, Li Wenru, Zhou Qiang
College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China; State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PR China.
College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
Comp Biochem Physiol C Toxicol Pharmacol. 2017 Dec;203:12-20. doi: 10.1016/j.cbpc.2017.10.005. Epub 2017 Oct 18.
The widespread and extensive application of insecticides have promoted the development of resistance in the brown planthopper Nilaparvata lugens (Stål), one of the most important rice pests in Asia. To better understand the underlying molecular mechanisms of metabolic resistance to insecticides, a chlorpyrifos-resistant (CR) strain of N. lugens was selected and its possible resistance mechanism was investigated. Synergistic tests using carboxylesterases (CarEs) inhibitor triphenyl phosphate (TPP) decreased the resistance of N. lugens to chlorpyrifos, and CarE activities could be induced by low concentrations of chlorpyrifos. Subsequently, a gene putatively encoding CarE, namely NlCarE, predominant in the midgut and ovary was isolated and characterized. The expression levels of NlCarE were detected and compared between the CR and a susceptible (SS) strain of N. lugens. Consistent with the increased CarE activity, this gene was overexpressed in the CR strain compared to the SS strain. The transcript levels of NlCarE were up-regulated by chlorpyrifos exposure, showing dose- and time-dependent expression patterns. Furthermore, RNA interference (RNAi)-mediated knockdown of NlCarE followed by insecticide application significantly increased the susceptibility of N. lugens to chlorpyrifos. These results demonstrate that NlCarE plays an important role in chlorpyrifos detoxification and its overexpression may be involved in chlorpyrifos resistance in N. lugens.
杀虫剂的广泛大量使用促进了褐飞虱（Nilaparvata lugens (Stål)）抗药性的发展，褐飞虱是亚洲最重要的水稻害虫之一。为了更好地理解对杀虫剂代谢抗性的潜在分子机制，我们筛选了褐飞虱的毒死蜱抗性（CR）品系，并研究了其可能的抗性机制。使用羧酸酯酶（CarEs）抑制剂磷酸三苯酯（TPP）进行的增效试验降低了褐飞虱对毒死蜱的抗性，低浓度的毒死蜱可诱导羧酸酯酶活性。随后，分离并鉴定了一个在中肠和卵巢中占主导地位的假定编码羧酸酯酶的基因，即NlCarE。检测并比较了褐飞虱CR品系和敏感（SS）品系中NlCarE的表达水平。与羧酸酯酶活性增加一致，与SS品系相比，该基因在CR品系中过表达。毒死蜱处理后NlCarE的转录水平上调，呈现剂量和时间依赖性表达模式。此外，通过RNA干扰（RNAi）介导敲低NlCarE后再施用杀虫剂，显著增加了褐飞虱对毒死蜱的敏感性。这些结果表明，NlCarE在毒死蜱解毒中起重要作用，其过表达可能与褐飞虱对毒死蜱的抗性有关。
