Engineered RNA nanostructures for scalable and efficient RNAi-based pesticides.

Double-stranded RNA (dsRNA)-based pesticides face challenges in stability, scalability, efficient uptake, and broad applicability. Here, we present self-assembled RNA nanostructures (SARNs), engineered to load pools of functional siRNAs with motifs that enhance hydrophobicity and elasticity, and enable both immediate and sustained siRNA release for efficient RNAi. SARNs improve RNA stability and delivery in plants and in model pests with chewing mouthparts (Tribolium castaneum) and piercing-sucking mouthparts (Nilaparvata lugens). Compared with dsRNA, SARNs demonstrated superior RNAi efficiency in T. castaneum and N. lugens, achieving significantly higher downregulation efficacy and mortality in both species. In addition, SARNs, which self-assemble from single-stranded (ss)RNA molecules, can be transcribed in Escherichia coli for scalable production. We further establish a framework for the laboratory-to-field transition of SARNs. This engineered RNA platform offers an efficient, scalable, cost-effective solution for RNA-based gene silencing, advancing applications in agriculture and biomedicine.