Rice recruiting resilience-conferring Enterobacter via enhanced proline and malic acid exudation under thiamethoxam...

Although pesticides are essential for ensuring stable agricultural production, how increasing pesticide stress influences crop recruitment of beneficial rhizosphere microorganisms remains unclear. In this study, we investigated how rice reshaped rhizosphere microbiota in response to the insecticide thiamethoxam (THIA) stress, with particular focus on the mechanistic relationship between root exudate chemistry and microbial recruitment. Through integrated transcriptomic and metabolomic analyses coupled with experimental validation, we demonstrate that THIA exposure triggers significant metabolic reprogramming in rice plants, particularly affecting amino acid metabolism and the tricarboxylic acid (TCA) cycle. These changes drive increased secretion of low-molecular-weight organic acids in root exudates, notably malic acid and proline. Chemical profiling revealed these compounds act as chemoattractants, selectively enriching pesticide-degrading and resistant bacterial taxa, with the genus Enterobacter showing particularly pronounced enrichment. Functional characterization of the dominant Enterobacter sp. isolate revealed upregulation of motility-related genes (yqxM, epsA, csgC, fimA, wcaA, and ftsZ) facilitating root colonization, which furthermore enhanced plant growth promotion and THIA stress mitigation upon root association. Notably, this plant-mediated microbial recruitment strategy exhibits dual benefits: environmental detoxification through microbial pesticide degradation and host fitness improvement via stress resilience enhancement. This work advances our understanding of plant-microbe-environment tripartite interactions, with significant implications for agricultural stress management, pollutant remediation strategies and food safety assurance.