Transcriptomic Profiling Identifies Key Genes and Pathways Involved in the Abiotic Stress Response of Trichoderma viride.

Trichoderma is a filamentous fungus with substantial industrial and agricultural value; however, its practical application is constrained by abiotic stresses such as drought, high temperatures, and salinity, particularly when these stresses occur simultaneously. The molecular mechanisms underlying the responses of Trichoderma to combined abiotic stresses remain insufficiently understood. In this study, the stress-tolerant Trichoderma viride strain Tv-1511 was analyzed using RNA sequencing to characterize its transcriptomic responses under PEG-simulated drought stress, and the resulting data were integrated with previously generated transcriptomic datasets from high-temperature (42 °C, 24 h) and salinity (300 mmol/L NaCl, 72 h) treatments. Under 50% Polyethylene glycol (PEG)-simulated drought, 4510 differentially expressed genes were identified and enriched in secondary metabolite biosynthesis and β-lactam antibiotic synthesis based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Integrating these drought stress data with the high-temperature and salinity datasets revealed 36 commonly upregulated and 29 commonly downregulated genes across triple stresses, primarily involved in redox processes and secondary metabolite synthesis. RT-qPCR validation indicated that Trichoderma mounts a synergistic response to multiple stresses by activating genes like MET17, ALDH (aminoglycoside synthesis), and FeSOD, Cu/ZnSOD, GCLC, GLO1, GST. These findings elucidate key transcriptomic mechanisms underlying Trichoderma responses to single and combined abiotic stresses and provide a theoretical foundation for the targeted improvement of stress-tolerant strains to enhance their agricultural and industrial utility.