Plastid engineering with an efficient RNAi delivery system based on bacteriophage MS2 virus-like particles enhances plant resistance to cotton bollworm

Dear Editor,RNA-based pesticides are approaching the market,offering great potential to control agricultural pests such as the coleopteran insect Diabrotica virgifera virgifera(Head et al.,2017).However,application to lepidopteran pests has been hampered by their inconsistent response to RNA interference(RNAi).As a notorious lepidoptera pest,Helicoverpa armigera feeds on over 300 species of host plants(Fu et al.,2022).Although transgenicplants expressingdouble-stranded RNAs or microRNAs that target essential insect genes can inhibit the growth of larvae,complete protection of the plants and efficient killing of this insect have not been achieved(Bally et al.,2020;Chung et al.,2021;Li et al.,2023).The relatively low RNAi efficiency in lepidopterans is mainly attributable to the degradation and intracellular sequestration of double-stranded RNA(Shukla et al.,2016;Zhu and Palli,2020).To overcome these obstacles and improve RNAi efficiency in H.armigera,we attempted to deliver RNAi molecules using a bacteriophage MS2 virus-like particle(VLP)-based delivery system(Wang et al.,2016).