Fungal-derived ZnO nanoparticles functionalized with riboflavin and UDP-GlcNAc exhibit potent nematicidal activity against M. incognita

This study reports the green synthesis of zinc oxide nanoparticles (ZnO NPs) using the nematophagous fungus Arthrobotrys oligospora and their evaluation as nematicidal agents against Meloidogyne incognita. The ZnO NPs were synthesized from fungal culture filtrate and characterized by UV-Vis, FTIR, XRD, Raman spectroscopy, SEM, TEM and EDAX confirming nanoscale particles (29.45-71.30 nm) with hexagonal wurtzite crystallinity. ^1H NMR-based metabolomics revealed functionalization of the nanoparticle surface with fungal metabolites, notably riboflavin and UDP-N-acetylglucosamine. In vitro bioassays demonstrated strong, dose-dependent nematicidal activity, achieving 94.8% juvenile mortality at 200 µg/mL after 72 h, significantly higher than the fungal extract alone (p < 0.05). Molecular docking showed that ZnO-riboflavin bound effectively to acetylcholinesterase and ZnO-UDP-GlcNAc to chitin synthase, suggesting dual disruption of neural signaling and cuticle biosynthesis. Collectively, these findings establish A. oligospora-mediated ZnO NPs as a metabolite-enriched nano-biocomposite with enhanced nematicidal efficacy, offering a novel and eco-friendly strategy for sustainable crop protection.