Development of a nanoparticle-mediated RNAi delivery system based on the biological function of G...

Pine wilt disease (PWD) caused by Bursaphelenchus xylophilus is a devastating forest pest, threatening pine species globally and causing massive economic losses. Chemical control is widely used but poses environmental and health risks, while RNA interference (RNAi) is an eco-friendly alternative hindered by dsRNA degradation. This study identified Bxgoa-1 as a key gene regulating B. xylophilus physiology and pathogenicity. Bioinformatics and immunolocalization confirmed its conservation and ubiquitous expression in the nematode. Silencing Bxgoa-1 via dsRNA soaking increased nematode mortality (40.74%), locomotion, reproduction, and pathogenicity to Pinus thunbergii. We optimized the self-assembly of dsBxgoa-1 with Star Polycation (SPc) at a 1:1 ratio, forming stable nanocomplexes that enhanced dsRNA stability, delivery efficiency, and silencing efficacy. The nanocomplex increased nematode mortality to 54.14% and reduced the disease index of pine seedlings to 43.70. This work demonstrates that the dsBxgoa-1/SPc nanocomplex provides a green, efficient strategy for PWD control, overcoming RNAi application barriers and facilitating the practical use of RNA-based pesticides in forest pest management.