State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China; Wuhan Academy of Agricultural Sciences, Wuhan 430070, China.
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China.
Pestic Biochem Physiol. 2022 Jun;184:105121. doi: 10.1016/j.pestbp.2022.105121. Epub 2022 May 14.
Pesticide resistance in pests drives the development of RNA interference (RNAi)-based technology as a novel approach for pest control. To investigate the effects of the positional dependency of double-stranded RNAs (dsRNAs), we newly designed four different 200 bp dsRNAs targeting Colorado potato beetle (CPB) β-Actin gene, termed as dsACT200-1 to dsACT200-4, to compare their insecticidal activity to CPB larvae together with our previously used 200 bp and 700 bp dsRNAs (dsACT200 and dsACT700), respectively (He et al., 2020a). Each of dsRNAs harbors different numbers of expected siRNAs predicted by sequence-based prediction platform, dsACT200 and dsACT200-2 have a relatively higher number of siRNA than other 200 bps dsRNAs. When CPB larvae were fed with in vitro synthesized dsRNA-painted potato leaves, all the tested dsRNAs showed significant effects to protect against CPB larvae. Combined with the survival rate of CPB larvae, β-Actin gene expression level and the surviving CPB larvae weight, various positional dsRNAs from the same allele showed different plant protection activity against CPB larvae and partially correlated with the predicted siRNA numbers and distribution on the target sequence. This study suggests the specific allelic locus for rational dsRNA design triggering RNAi efficiency for target gene silencing is an essential factor in enhancing the insecticidal activity.
害虫对杀虫剂的抗药性促使人们开发 RNA 干扰（RNAi）技术作为一种新型的害虫防治方法。为了研究双链 RNA（dsRNA）位置依赖性的影响，我们新设计了针对马铃薯甲虫β-肌动蛋白基因的四种不同的 200bp dsRNA，分别命名为 dsACT200-1 到 dsACT200-4，以比较它们与我们之前使用的 200bp 和 700bp dsRNA（dsACT200 和 dsACT700）一起对马铃薯甲虫幼虫的杀虫活性（He 等人，2020a）。每种 dsRNA 都含有不同数量的预期 siRNA，这些 siRNA 是通过基于序列的预测平台预测的，dsACT200 和 dsACT200-2 比其他 200bp dsRNA 具有更高数量的 siRNA。当马铃薯甲虫幼虫喂食体外合成的 dsRNA 涂覆的马铃薯叶片时，所有测试的 dsRNA 都对防治马铃薯甲虫幼虫表现出显著效果。结合马铃薯甲虫幼虫的存活率、β-肌动蛋白基因表达水平和幸存的马铃薯甲虫幼虫体重，来自同一等位基因的各种位置 dsRNA 对马铃薯甲虫幼虫表现出不同的植物保护活性，部分与目标序列上预测的 siRNA 数量和分布相关。本研究表明，针对特定等位基因座进行合理的 dsRNA 设计，触发靶基因沉默的 RNAi 效率，是增强杀虫活性的一个重要因素。
