文献类型：期刊文献

英文题名：Rolling circle transcription: A new system to produce RNA microspheres for improving RNAi efficiency in an agriculturally important lepidopteran pest (Mythimna separate)

作者：Zhu, Yutong[1];Kong, Linghao[1];Wang, Xinqian[1];Xu, Jiazheng[1];Qian, Xuhong[1];Yang, Yangyang[1];Xu, Zhiping[1];Zhu, Kun Yan[2]

机构：[1]East China Univ Sci & Technol, Sch Pharm, Shanghai Key Lab Chem Biol, Shanghai 200237, Peoples R China;[2]Kansas State Univ, Dept Entomol, Manhattan, KS 66506 USA

年份：2023

卷号：197

外文期刊名：PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001124487500001)】；

基金：Funding This work is supported by National Key Research and Development Program (2022YFD1700400 and 2023YFD1700300) .

语种：英文

外文关键词：Mythimna separate; Pest management; RNA interference; RNA microsphere; Rolling circle transcription; miRNA pathway

摘要：We applied a new RNA interference (RNAi) system using rolling circle transcription (RCT) technology to generate RNA microspheres (RMS) for targeting two key chitin synthetic pathway genes [chitin synthase A (CHSA), chitin synthase B (CHSB)] in the larvae of the oriental armyworm (Mythimna separate), a RNAi-unsusceptible agriculturally important lepidopteran pest. Feeding the third-instar larvae with the RMS-CHSA- or RMS-CHSBtreated corn leaf discs suppressed the expression of CHSA by 81.7% or CHSB by 88.1%, respectively, at 72 h. The silencing of CHSA consequently affected the larval development, including the reduced body weight (54.0%) and length (41.3%), as evaluated on the 7th day, and caused significant larval mortalities (51.1%) as evaluated on the 14th day. Similar results were obtained with the larvae fed RMS-CHSB. We also compared RNAi efficiencies among different strategies: 1) two multi-target RMS [i.e., RMS-(CHSA + CHSB), RMS-CHSA + RMS-CHSB], and 2) multi-target RMS and single-target RMS (i.e., either RMS-CHSA or RMS-CHSB) and found no significant differences in RNAi efficiency. By using Cy3-labeled RMS, we confirmed that RMS can be rapidly internalized into Sf9 cells (<6 h). The rapid cellular uptake of RMS accompanied with significant RNAi efficiency through larval feeding suggests that the RCT-based RNAi system can be readily applied to study the gene functions and further developed as bio-pesticides for insect pest management. Additionally, our new RNAi system takes the advantage of the microRNA (miRNA)-mediated RNAi pathway using miRNA duplexes generated in vivo from the RMS by the target insect. The system can be used for RNAi in a wide range of insect species, including lepidopteran insects which often exhibit extremely low RNAi efficiency using other RNAi approaches.