Nanocellulose-Integrated BioClay to Improve Stability and Efficacy in RNA Interference-Mediated Antiviral Protection of Plants.

RNA interference (RNAi) technology offers a nontransgenic and sequence-specific strategy for plant protection, but its foliar application in the field is limited by rapid RNA degradation and poor persistence on leaf surfaces. Here, we developed a nanocellulose-enabled clay-based platform for double-stranded RNA (dsRNA) foliar delivery, named as BioClay@CNF, that offers dsRNA persistence on leaves and durable antiviral activity in plants. Incorporation of nanocellulose fibers (CNFs) increased dsRNA retention and resisted rain-induced wash-off while simultaneously shielding dsRNA from enzymatic and thermal degradation under fluctuating pH and humidity conditions. The fibrous CNF network enhanced water retention and rehydration of the formulation on the leaf surface, which may help maintain local dsRNA availability under fluctuating environmental conditions. Using the cucumber mosaic virus as a model system, BioClay@CNF exhibited 85.1% viral inhibition for 20 days while significantly reducing visual damage and increasing leaf dry weight with higher chlorophyll content. These findings demonstrated that BioClay@CNF offers a promising strategy for sustainable management of plant virus diseases.