Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, 37996, USA.
Bayer Crop Science, 700 Chesterfield Pkwy West, FF4336B, Chesterfield, MO, 63017, USA.
Sci Rep. 2021 Mar 22;11(1):6523. doi: 10.1038/s41598-021-85876-1.
Insecticidal double-stranded RNAs (dsRNAs) silence expression of vital genes by activating the RNA interference (RNAi) mechanism in insect cells. Despite high commercial interest in insecticidal dsRNA, information on resistance to dsRNA is scarce, particularly for dsRNA products with non-transgenic delivery (ex. foliar/topical application) nearing regulatory review. We report the development of the CEAS 300 population of Colorado potato beetle (Leptinotarsa decemlineata Say) (Coleoptera: Chrysomelidae) with > 11,100-fold resistance to a dsRNA targeting the V-ATPase subunit A gene after nine episodes of selection using non-transgenic delivery by foliar coating. Resistance was associated with lack of target gene down-regulation in CEAS 300 larvae and cross-resistance to another dsRNA target (COPI β; Coatomer subunit beta). In contrast, CEAS 300 larvae showed very low (~ 4-fold) reduced susceptibility to the Cry3Aa insecticidal protein from Bacillus thuringiensis. Resistance to dsRNA in CEAS 300 is transmitted as an autosomal recessive trait and is polygenic. These data represent the first documented case of resistance in an insect pest with high pesticide resistance potential using dsRNA delivered through non-transgenic techniques. Information on the genetics of resistance and availability of dsRNA-resistant L. decemlineata guide the design of resistance management tools and allow research to identify resistance alleles and estimate resistance risks.
杀虫双链 RNA(dsRNA) 通过激活昆虫细胞中的 RNA 干扰 (RNAi) 机制来沉默重要基因的表达。尽管人们对杀虫 dsRNA 具有很高的商业兴趣，但有关 dsRNA 抗性的信息却很少，特别是对于具有非转基因递送（例如叶面/表面应用）且接近监管审查的 dsRNA 产品。我们报告了科罗拉多马铃薯甲虫（Leptinotarsa decemlineata Say）（鞘翅目：叶甲科）CEAS 300 种群的发展，该种群对靶向 V-ATPase 亚基 A 基因的 dsRNA 具有超过 11100 倍的抗性，经过 9 次非转基因叶面涂层递送选择后获得。抗性与 CEAS 300 幼虫中靶基因下调缺乏有关，并且与另一个 dsRNA 靶标（COPIβ；衣壳蛋白亚基β）存在交叉抗性。相比之下，CEAS 300 幼虫对苏云金芽孢杆菌的 Cry3Aa 杀虫蛋白表现出非常低的（约 4 倍）易感性。CEAS 300 中的 dsRNA 抗性作为常染色体隐性性状遗传，是多基因的。这些数据代表了使用非转基因技术递送 dsRNA 后，首例具有高农药抗性潜力的昆虫害虫对 dsRNA 的抗性案例。抗性的遗传学信息和 dsRNA 抗性 L. decemlineata 的可用性指导了抗性管理工具的设计，并允许研究确定抗性等位基因并估计抗性风险。
