Star polycation nanoplatform improves dsRNA stability and delivery for RNAi-Based control of Meloidogyne enterolobii

ABSTRACT Meloidogyne enterolobii is an extremely pathogenic soil-borne pest, RNA interference (RNAi) represents a highly targeted eco-friendly control strategy, but its application is limited by poor dsRNA stability and low cellular uptake efficiency. Herein, we developed a star polycation (SPc)-based nanocarrier system to enhance the stability and cellular uptake of dsRNA for efficient control of M . enterolobii . We identified Mekk-3 as a potential candidate gene in M. enterolobii . SPc spontaneously assembled with ds Mekk-3 to form nanoscale complex that protected dsRNA from degradation by RNase A, soil extract, and nematode lysate. Compared with naked dsRNA, the ds Mekk-3 /SPc complex increased dsRNA uptake by 42.3% within 24 h, enhanced gene silencing by 1.9-fold, and significantly increased larval mortality. Transcriptome profiling further supported the involvement of endocytosis and transport-related pathways in SPc-mediated delivery, whereas Mekk-3 silencing may lead to the suppression of MAPK-related genes. In greenhouse trials, the complex reduced larval infection and gall formation. Collectively, these results identify Mekk-3 as a potential RNAi target gene, and establish SPc as a viable delivery platform for next-generation RNA-based bionematicides.