Dendritic mesoporous silica-delivered siRNAs nano insecticides to prevent Sogatella furcifera by inhibiting metabolic detoxification and reproduction

Abstract

Abstract Background Migratory insect infestation caused by Sogatella furcifera is a serious threat to rice production. The most effective method available for S. furcifera control is intensive insecticide spraying, which cause widespread resistance. RNA interference (RNAi) insecticides hold enormous potential in managing pest resistance. However, the instability and the poor efficiency of cross-kingdom RNA trafficking are key obstacles for the application in agricultural pest management. Methods We present dendritic mesoporous silica nanoparticles (DMSNs)-based nanocarrier for delivering siRNA and nitenpyram to inhibit the metabolic detoxification and development of S. furcifera, thereby preventing its proliferation. Results This nano complex (denoted as N@UK-siRNA/DMSNs) significantly enhanced the stability of siRNA (efficacy lasting 21 days) and released cargos in GSH or planthopper bodily fluid with a maximum release rate of 84.99%. Moreover, the released UK-siRNA targeting two transcription factors (Ultraspiracle and Krüppel-homolog 1) downregulated the developmental genes Ultraspiracle (0.09-fold) and Krüppel-homolog 1 (0.284-fold), and downstream detoxification genes ABC SfABCH4 (0.016-fold) and P450 CYP6FJ3 (0.367-fold). Conclusion The N@UK-siRNA/DMSNs inhibited pest development and detoxification, significantly enhancing susceptibility to nitenpyram to nanogram level (LC50 is 250–252 ng/mL), resulting in a 5.37–7.13-fold synergistic ratio. This work proposes a comprehensive management strategy for controlling S. furcifera to ensure the green and safe production of rice. Graphical Abstract Schematic fabrication of the N@UK-siRNA/DMSNs and the molecular mechanism resolution of improving the sensitivity of S. furcifera to nitenpyram. The nitenpyram and UK-siRNA are assembled onto the DMSNs by interfacial modification. With phloem and xylem pathway, the N@UK-siRNA/DMSNs could transport bi-directionally to the feeding sites of S. furcifera and then release nitenpyram and UK-siRNA in S. furcifera in response to glutathione (GSH). The UK-siRNA released from N@UK-siRNA/DMSNs would downregulate the developmental genes USP and Kr-H1. The releasing nitenpyram would competitively bind to acetylcholine (ACh) receptors, inhibiting the transmission of nerve impulses

Keywords

• Sogatella furcifera
• Insecticide resistance management
• RNAi pesticides
• Insecticides delivery
• Dendritic mesoporous silica nanoparticles