From stability to persistence: Insights into nanoparticle-formulated dsRNA in RNAi-based fungal disease control

Fungal pathogens significantly impact global crop production, leading to substantial economic losses and threatening food security. Chemical fungicides remain the primary tools for disease management, deployed to control fungal pathogens. The extensive use of conventional fungicides raises concerns over environmental and human health issues and fungicide resistance, creating demand for alternative control methods for fungal diseases in agriculture. Spray-induced gene silencing (SIGS), a non-transgenic RNA interference (RNAi)-based strategy utilizing the topical application of double-stranded RNAs (dsRNAs), has emerged as a promising alternative for sustainable fungal disease management, including in emerging controlled environment agriculture (CEA) systems. SIGS enables gene-specific silencing in pathogens and offers species-specific control with minimal ecological disruption. However, the environmental instability of naked dsRNAs limits field efficacy. Notably, recent advancements in nanocarrier-based delivery systems, such as chitosan nanoparticles, layered double hydroxide clays, and bacterial minicells have enhanced dsRNA stability, uptake, and bioavailability under field conditions, opening new possibilities for the future of crop protection. Despite these innovations, knowledge gaps remain in understanding the environmental fate, degradation kinetics, and off-target risks of more stable dsRNA, including nanocarrier-formulated dsRNAs, especially CEA systems. We highlight the progress in SIGS mechanisms, nanocarrier-enhanced delivery systems, environmental persistence, and biosafety considerations, and outline future research directions for integrating SIGS-based biopesticides into mainstream crop protection strategies.