Integrative proteomics and metabolomics map reveals key sectors of defense metabolism in ginger against Pythium myriotylum

Abstract

Ginger (Zingiber officinale) cultivation is severely threatened by rhizome rot caused by Pythium myriotylum. Hitherto, detail molecular machineries and metabolic pathways of defense against P. myriotylum in edible ginger are elusive. To elucidate the defense mechanisms, we employed integrative quantitative proteomics (TMT labelling) and high resolution untargeted metabolomics to investigate temporal defense responses of ginger during infection. Proteomics analysis revealed enrichment of cellular detoxification and secondary metabolism pathways indicating co-activation of oxidative stress management and its mediated defense metabolite biosynthesis. Key phenylpropanoid enzymes (PAL, C4H, CAD) and LOX, a regulator of jasmonic acid (JA) biosynthesis, were significantly up-regulated, correlating JA signaling with secondary metabolic defenses. Metabolomics profiling confirmed accumulation of phenylpropanoids, flavonoids, and terpenoids, including known antimicrobial metabolites such as gingerol, shogaol, curcumin, and gingerdione, alongside expression of their key regulatory enzyme was also induced. Notably, machine learning identified the monoterpenoid TGA as the top defense-associated metabolite. Functional assays demonstrated strong anti-P. myriotylum activity of TGA, which inhibited mycelial growth and suppressed expression of key pathogenicity-related genes (NIP1, GHs, cellulase). These findings highlight coordinated activation of detoxification and secondary metabolic pathways in ginger defense and establish TGA as a promising bio-control agent against P. myriotylum.