Objective To elucidate the inhibitory effect and mechanism of nano-platinum disinfectant against Fusarium oxysporum f. sp. cubense.

Method The sensitivity of F. oxysporum f. sp. cubense to nano-platinum disinfectant was determined using the mycelial growth rate method on PDA plates containing the disinfectant, establishing the EC₅₀. Morphological alterations in hyphae following exposure to the disinfectant were directly observed via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Transcriptome sequencing of treated strains was performed, followed by gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses. Differentially expressed genes (DEGs) were mined from the transcriptome data to analyze changes in gene expression and reveal the intrinsic mechanism.

Result Nano-platinum disinfectant exhibited potent inhibitory activity against F. oxysporum f. sp. cubense with EC₅₀ of 5.94 μL/mL, while the inhibition rate increasing significantly with higher concentrations. SEM and TEM results revealed that treated hyphae suffered severe mechanical damage, compromised cell wall integrity, abnormal cell membrane structure, and organelle dysfunction. Analysis of key DEGs revealed the following patterns: a general upregulation of genes related to reactive oxygen species (ROS) stress; increased expression of fatty acid desaturase (FAD) genes; a general downregulation of genes associated with chitinase and chitin synthase; reduced expression of genes involved in ribosome synthesis and function; downregulation of genes responsible for critical processes in RNA synthesis, processing, and degradation; decreased expression of genes in the MAPK, cAMP, and G-protein signaling pathways; and downregulation of genes related to DNA repair.

Conclusion Nano-platinum disinfectant demonstrates significant efficacy in inhibiting F. oxysporum f. sp. cubense. Its antifungal mechanism is closely associated with the induction of ROS stress response. This study provides a theoretical foundation for the subsequent application of nano-platinum disinfectant in controlling banana Fusarium wilt.