Imidazole-Modified Graphene Quantum Dots Enhance RNAi Efficiency in Spodoptera litura (Lepidoptera: Noctuidae): A Study Using Cuticular Protein Gene Silencing

Abstract

RNA interference (RNAi) serves as a crucial tool for gene function research and pest control. Nevertheless, its application in lepidopteran insects is restricted by the low efficiency of gene silencing. Spodoptera litura (Lepidoptera: Noctuidae), a globally-distributed polyphagous agricultural pest, has developed multiple strategies to resist control measures. This situation highlights the urgent need for innovative strategies to promote functional genomics and molecular target characterization studies. In this study, a novel cuticular protein SlCP was identified, which is vital for epidermal development and larval survival. Silencing of SlCP gave rise to epidermal contraction, a reduction in body size, a decrease in feed intake, and larval mortality. To address the problem of low RNAi efficiency, imidazole-modified graphene quantum dots (IGQDs) were utilized as nanocarriers for the delivery of dsSlCP. IGQD mediated delivery led to a 4.65-fold greater reduction in SlCP transcript levels compared with naked double-stranded RNA and elevated larval mortality from 38.00% to 56.00%. These findings establish that SlCP functions in epidermal development and present a nanomaterial-assisted strategy that enhances RNAi delivery efficacy in S. litura.