• • Exogenous ARB exposure at 1×10^8 CFU/mL suppressed wheat seedling root length by 68.83% and shoot length by 36.87%, demonstrating a concentration-dependent phytotoxic effect that could compromise crop establishment in contaminated soils.
• • Root endophytic community shifted dramatically: Clostridium_sensu_stricto_5 surged to 45.02% relative abundance by exposure end, indicating a potential ARG reservoir that may persist and propagate resistance in the plant microbiome.
• • Rhizosphere community remained dominated by Betaproteobacteriales (including Delftia, Curvibacter, Comamonas, Achromobacter), with their relative abundance increasing over time, suggesting selective enrichment of specific taxa under ARB pressure.
• • The proportion of ARB-carrying endophytes correlated significantly (P<0.05) with Clostridium_sensu_stricto_5, Clostridium_sensu_stricto_1, Bacillus, and Paenibacillus abundances, implicating these genera as primary hosts for acquired ARGs in wheat roots.