Nuclear Receptors as Lethal Targets in the White-Backed Planthopper via RNAi and Nanocarrier Delivery

Nuclear receptors (NRs) are master regulators of insect ecdysis, metamorphosis, and reproduction, ideal targets for eco-friendly pest control. However, no comprehensive functional screening of the entire NR family has been conducted in any of the insect species. Here, we systematically identified 21 NR genes in the white-backed planthopper (<i>Sogatella furcifera</i>, WBPH), a major rice pest, and conducted an RNA interference (RNAi) screen via microinjection. Five highly lethal targets (<i>SfHR38-3</i>, <i>SfHR39</i>, <i>SfHR51</i>, <i>SfEG</i>, and <i>SfE75</i>) were validated using a spray-induced and nanocarrier-delivered gene silencing (SI-NDGS) system, causing severe ecdysis failure and wing deformities. Transcriptomic analyses of previously uncharacterized <i>SfEG</i> and <i>SfHR51</i> reveal that <i>SfEG</i> is an essential mediator of ecdysone signaling for epidermal development, while <i>SfHR51</i> integrates cellular proteostasis with hormonal control of development. This study introduces a dual innovation: potent species-specific RNAi targets and the functional characterization of previously unknown NRs, establishing a mechanistic framework for next-generation, eco-friendly biopesticides.