Specific Metabolites Modulate Core Microbes and Microbial Interactions to Drive Fomesafen Dissipation in the Soybean Rhizosphere

Abstract

Rhizosphere metabolites regulate organic pollutant dissipation through microbiome modulation, yet dynamic interrelationships among metabolite shifts, microbial assembly, and pollutant removal remain unclear. Using multiomics (16S rRNA sequencing, metabolomics, and metagenomics), this study deciphered the temporal dynamics of rhizosphere metabolites and microbiome during the dissipation of fomesafen in soybean pots. Fomesafen dissipation exhibited biphasic kinetics during soybean growth, with an initial rapid phase followed by prolonged stabilization, which was synchronized with time-dependent microbiome perturbations of initial enrichment and subsequent attenuation. Metabolomics revealed fomesafen-induced shifts in rhizosphere metabolites, with 2-naphthalenesulfonic acid (↓20.84%) and 2-hydroxyoctadecanoic acid (↑13.30%) exhibiting opposing effects on microbial assembly, which ultimately affect fomesafen dissipation, as outlined in our conceptual model. Microcosm experiments further demonstrated 2-naphthalenesulfonic acid enhanced while 2-hydroxyoctadecanoic acid inhibited fomesafen dissipation. Our findings highlight the significance of rhizosphere metabolite-mediated interactions between core microbes and potential fomesafen-degraders in governing fomesafen dissipation.