Strategy development for enhancing Trichoderma longibrachiatum biocontrol efficacy based on integrated functional omics.

Biocontrol using beneficial microbes like Trichoderma is an eco-friendly strategy for plant disease management but is limited by poor soil colonization and low secondary metabolite production. This study isolated Trichoderma longibrachiatum Tr-8, which shows strong cellulose degradation and resource competition. Integrated omics revealed Tr-8's preference for cellulose-based carbon, promoting polyketosynthase gene expression. Heat-killed Bacillus subtilis acted as an environmental inducer, activating secondary metabolism genes up to 65-fold. A combined treatment of wheat straw and heat-killed Bacillus subtilis increased secondary metabolite yield by 1.5 times, improved tobacco bacterial wilt control by 14.3%, and raised soil Trichoderma abundance by 1.2-fold. These results offer novel strategies to enhance Trichoderma colonization and biocontrol efficacy, while valorizing agricultural waste and synergistically managing soil-borne pathogens.