Root exudate metabolites modulate rhizosphere microbiome to suppress Fusarium wilt

Beneficial interactions between plants and rhizosphere microbes are essential for plant health, yet the mechanisms underlying plant-derived metabolite-mediated soilborne disease suppression remain unclear. Using bitter gourd (Momordica charantia) and its pathogen Fusarium oxysporum f. sp. momordicae (FOM) as a model, we investigated the role of Chinese chive root exudates (RECs) in modulating rhizosphere microbiota and plant immunity. Our results showed that benzoic acid and L-pyroglutamic acid, key metabolites in RECs, inhibited FOM growth in vitro and reduced Fusarium wilt severity in planta. These metabolites reshaped root-associated bacterial communities and enhanced plant defense enzymes. Shotgun metagenomics revealed that benzoic acid and L-pyroglutamic acid enriched GH23 family genes, potentially increasing glycoside hydrolase activity to degrade FOM cell walls and suppress fungal growth. The dual role of these metabolites in pathogen inhibition and immune activation highlights their potential as biocontrol agents. This study offers insights into leveraging plant-derived metabolites to manage soilborne diseases sustainably.