Trichoderma enriches Burkholderia via cross-feeding of degradation intermediates to enhance atrazine degradation and alleviate soybean phytotoxicity

The widespread agricultural use of atrazine threatens soil health, and residual phytotoxicity in corn-soybean rotation systems necessitates sustainable remediation strategies. By leveraging the atrazine-degrading fungus Trichoderma lentiforme HN154, we achieved an 80.3% removal of atrazine (500 mg/kg) in non-sterilized soils from a corn planting system within 14 days, 22.1% higher degradation than in sterilized soil, while concurrently alleviating phytotoxic symptoms in soybean plants. Metagenomic analysis revealed that colonization by T. lentiforme HN154 drove restructuring of microbial networks, enriching the keystone family Burkholderiaceae, which was strongly associated with atrazine catabolism and four key catabolic enzymes (EC 3.5.4.43 (atzB), EC 3.5.1.131 (atzE), EC 3.5.1.54 (atzF), EC 3.5.4.42 (atzC)). Among 23 rhizosphere isolates, the Burkholderia strains Bur-4, Bur-5, and Bur-14 showed the highest atrazine degradation rates (26.3% - 29.4%) within 72 h. A Trichoderma-Burkholderia synthetic consortium further enhanced remediation by boosting plant antioxidant defenses (SOD, POD, CAT) and reducing oxidative damage (MDA). Mechanistically, intermediates (hydroxyatrazine and biuret) generated during T. lentiforme HN154-mediated degradation stimulated Burkholderia chemotaxis, swarming and swimming motility, while cross-feeding on these metabolites synergistically accelerated bioaugmentation (the Trichoderma-Burkholderia synthetic consortium achieved rapid atrazine degradation of 86.3% within 168 h). This study reveals tripartite interactions among exogenous microbial degraders, pollutant metabolites, and indigenous microbiota, offering a strategic foundation for microbiome-guided, precision bioaugmentation to restore soil ecological health and crop resilience.