Multiomics Insights into Nanoscale Boron Nitride Mediated Antioxidant Defense and Metabolic Reprogramming in Cucumber in Response to Fusarium Infection

Fusarium poses a significant threat to the global crop productivity and food security. This study evaluated the mechanisms of nanoscale boron nitride (nano-BN, 0–500 mg/kg) against Fusarium oxysporum in cucumber. Fusarium infection severely impaired plant growth with biomass declining by 60%. However, 50 mg/kg nano-BN treatment significantly increased shoot biomass by 64.9% compared to disease controls, restoring photosynthetic parameters to near-healthy levels. Nano-BN inhibited Fusarium proliferation by disrupting hyphal and spore structures and reduced mycotoxin production (beauvericin and enniatin) by over 63%. Metabolomic analysis demonstrates that nano-BN mitigated oxidative stress by enhancing glutathione metabolism, with significant increases in glutathione and ascorbic acid content by 166.67% and 478.78%, respectively. Importantly, the protein–protein interaction network shows that nano-BN counteracted Fusarium-induced suppression of ribosomal proteins and endoplasmic reticulum stress-related proteins, promoting protein synthesis and folding. The coexpression network identified sucrose and geshoidin as key metabolites linked to ribosomal and mitochondrial proteins, bridging metabolic resilience with enhanced disease resistance. Multiomics analysis suggests that nano-BN alleviated the Fusarium stress by regulating the phenylpropanoid biosynthesis and restoring the expression levels of key enzymes in carbohydrate metabolism. Overall, nano-BN effectively mitigates Fusarium stress by enhancing plant growth and modulating metabolic processes, offering a promising strategy for plant protection.