DIMBOA and melatonin mediate a recruitment feedback loop between wheat and Bacillus pseudomycoides to alleviate...

Herbicide residues disrupt soil-plant-microbe interactions and threaten agricultural sustainability, yet how plants actively recruit beneficial microbes to mitigate stress remains unclear. Here, we uncover a metabolite-mediated recruitment model in which wheat secretes DIMBOA and melatonin in response to bensulfuron-methyl (BM) stress to recruit Bacillus pseudomycoides A3, with cross-sectional evidence supporting a self-reinforcing feedback architecture. Chemotaxis assays confirmed that DIMBOA and melatonin act as potent chemoattractant for strain A3 at environmentally relevant concentrations. Under BM stress, A3 upregulates the key biosynthetic genes TaBx6 (by 265.7%) in leaves and TaSNAT (by 23.1%) in roots, boosting the production of DIMBOA and melatonin. This metabolite-mediated recruitment feedback loop directly reduces BM residues in plant tissues (12.8-19.6%), optimizing the rhizosphere microbiome by enriching beneficial taxa and enhancing plant metabolic defense. Our findings reveal that plants actively modulate rhizosphere microbial immunity through metabolite-mediated microbial recruitment, providing a new paradigm for developing green bioremediation strategies for herbicide-contaminated agricultural soils.