Nanoparticle-enhanced multi-target RNAi in Myzus persicae: molecular mechanisms, cross-kingdom sRNA transfer, and efficacy for sustainable pest management

The green peach aphid ( Myzus persicae ) represents a challenging agricultural pest, capable of harming crops through direct feeding damage and as an important virus vector. While RNA interference (RNAi) offers a promising species-specific control strategy, its application has been hindered by inefficient dsRNA uptake by both plants and insects. This study systematically evaluates carbon dot (CD) and chitosan-tripolyphosphate (ChNP) nanoparticles as delivery vehicles for simultaneous dsRNA targeting of five essential aphid genes (acetylcholinesterase-like, nicotinic acetylcholine receptor, carboxylesterase, cytochrome P450, and Ya1 lncRNA). We found that nanoparticle complexation enhanced dsRNA delivery on pepper leaves up to 3.7–14.0-fold compared to naked dsRNA ( P  < 0.001). Results showed reduced target transcript levels in aphids by 82–99% when using coated dsRNAs, culminating in 93.5% mortality (CD:dsRNA), effects mirroring those of the insecticide spirotetramat (91.0% mortality) at 6 d. Non-target dsGFP did not induced gene silencing or mortality. In greenhouse experiments, plants treated with ChNP:dsRNA exhibited significantly greater aerial biomass compared to untreated controls ( P  < 0.001) and spirotetramat-treated plants ( P  = 0.006). While CD:dsRNA-treated plants showed comparable aerial mass to insecticide-treated ones, the latter displayed reduced photosynthetic efficiency ( P  < 0.05) and partial defoliation. High-throughput sequencing revealed efficient processing of nanoparticle-delivered dsRNAs within pepper plants and subsequent transfer to feeding aphids. Differential expression analysis of M. persicae miRNAs identified several significantly altered miRNAs in response to dsRNA treatment, with Gene Ontology analysis revealing enrichment of terms related to plasma membrane, cell-cell adhesion, transcriptional regulation, and G protein-coupled receptor signaling. These findings provide compelling evidence for nanocarrier-mediated RNAi as an effective and environmentally favorable aphid control strategy with minimal impact on beneficial insects.