Chitosan boosts ginger disease resistance: Insights from transcriptomic and metabolomic analyses

Chitosan exhibits efficacy in controlling ginger diseases, yet its systemic regulatory mechanisms remain unknown. This study explored the potential mechanisms underlying chitosan-regulated resistance by conducting physiological, comparative transcriptome, and metabolome analyses in Fusarium solani-inoculated ginger rhizomes with and without chitosan treatment. Chitosan treatment decreased decay severity and water loss, and reduced reactive oxygen species accumulation by enhancing antioxidant enzyme activities. Chitosan increased PAL, C4H, and CHI activities, along with elevated levels of lignin, total phenolic, total flavonoid, and the accumulation of suberin polyphenolic. RNA-seq analysis identified 1158 differentially expressed genes, predominantly involved in active oxygen and phenylpropanoid metabolism. Metabolomics identified 226 differential metabolites, including numerous phenylpropanoids and flavonoids. Integrated RNA-seq and metabolome analyses revealed chitosan's regulatory impact on gene expression and metabolite accumulation in the phenylpropanoid metabolism. These findings provide novel insights into chitosan's mechanisms against Fusarium solani.