PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

RNA interference (RNAi) is a highly sequence-specific regulatory process that suppresses gene expression at the post-transcriptional level. It serves essential biological functions in eukaryotes, including antiviral defence, control of transposable elements, and regulation of endogenous gene activity. Owing to its high specificity and targeted mode of action, RNAi has gained recognition as a precise and environmentally sustainable tool for next-generation pest management strategies. By targeting essential genes involved in development, metabolism, reproduction, and cellular homeostasis, double-stranded RNA (dsRNA)-mediated silencing induces high mortality, growth inhibition, and reduced fecundity across diverse insect orders. Functional genomic studies have identified numerous high-efficacy targets across insect orders, particularly genes involved in proteasomal degradation, transcriptional regulation, chitin biosynthesis, hormonal signalling (ecdysone pathway), vacuolar ATPase activity, and apoptosis. Host-Induced Gene Silencing (HIGS), Spray-Induced Gene Silencing (SIGS) and plastid-mediated RNAi (PM-RNAi) are among the delivery mechanisms for dsRNA. While HIGS and PM-RNAi provide sustained in planta dsRNA expression, SIGS offers a flexible, non-transgenic alternative for rapid field application. Advances in genome-wide target identification, optimised delivery systems, and nanocarrier-mediated stabilisation have significantly improved dsRNA stability against UV exposure and nuclease degradation, as well as RNAi efficacy through transcuticular and gut epithelial uptake. These developments position RNAi as a highly specific, environmentally benign, and scalable biopesticide strategy with strong potential to complement or replace conventional chemical insecticides in integrated pest management programmes.