College of Plant Science &Technology, Huazhong Agricultural University, Wuhan 430070, China.
Pest Control Division, National Agricultural Technology Extension and Service Center, Ministry of Agricultural, Beijing 100125, China.
Sci Rep. 2016 Jun 29;6:28697. doi: 10.1038/srep28697.
RNA interference (RNAi) is a robust tool to study gene functions as well as potential for insect pest control. Finding suitable target genes is the key step in the development of an efficient RNAi-mediated pest control technique. Based on the transcriptome of Chilo suppressalis, 24 unigenes which putatively associated with insect hormone biosynthesis were identified. Amongst these, four genes involved in ecdysteroidogenesis i.e., ptth, torso, spook and nm-g were evaluated as candidate targets for function study. The partial cDNA of these four genes were cloned and their bacterially expressed dsRNA were fed to the insects. Results revealed a significant reduction in mRNA abundance of target genes after 3 days. Furthermore, knocked down of these four genes resulted in abnormal phenotypes and high larval mortality. After 15 days, the survival rates of insects in dsspook, dsptth, dstorso, and dsnm-g groups were significantly reduced by 32%, 38%, 56%, and 67% respectively, compared with control. Moreover, about 80% of surviving larvae showed retarded development in dsRNA-treated groups. These results suggest that oral ingestion of bacterially expressed dsRNA in C. suppressalis could silence ptth, torso, spook and nm-g. Oral delivery of bacterially expressed dsRNA provides a simple and potential management scheme against C. suppressalis.
RNA 干扰 (RNAi) 是研究基因功能以及昆虫害虫防治潜力的强大工具。寻找合适的靶基因是开发高效 RNAi 介导的害虫防治技术的关键步骤。基于斜纹夜蛾的转录组，鉴定了 24 个与昆虫激素生物合成相关的假定基因。在这些基因中，评估了 4 个参与蜕皮激素生物合成的基因，即 ptth、torso、spook 和 nm-g，作为功能研究的候选靶标。这些四个基因的部分 cDNA 被克隆，并将其细菌表达的 dsRNA 喂食给昆虫。结果表明，靶基因的 mRNA 丰度在 3 天后显著降低。此外，这些四个基因的敲低导致异常表型和高幼虫死亡率。15 天后，dsspook、dsptth、dstorso 和 dsnm-g 组昆虫的存活率分别比对照组显著降低 32%、38%、56%和 67%。此外，dsRNA 处理组约 80%的存活幼虫发育迟缓。这些结果表明，斜纹夜蛾中细菌表达的 dsRNA 的口服摄入可以沉默 ptth、torso、spook 和 nm-g。细菌表达的 dsRNA 的口服递送为斜纹夜蛾提供了一种简单且有潜力的管理方案。
