Table 2_Comparative study on the molecular mechanisms of Trichoderma, Cladosporium and Penicillium strains (Ascomycota) in positively regulating Festuca sinensis cv. Qinghai based on multi-omics.docx

IntroductionFestuca sinensis cv. Qinghai is a key ecological forage on the Qinghai-Tibet Plateau, but its slow natural growth hinders grassland restoration. Strains of the genera Trichoderma, Cladosporium and Penicillium are research hotspots in agriculture owing to their prominent plant growth-promoting and stress-tolerance enhancing properties. However, the differences in growth-promoting effects and underlying molecular mechanisms among their genera remain poorly elucidated.
MethodsIn this study, F. sinensis was treated with strains of endophytic Ascomycota (classified into the genera Trichoderma, Cladosporium, and Penicillium), followed by comprehensive analysis of forage growth-related traits and rhizospheric soil enzyme activities, combined with integrative metabolomics and transcriptomics.
ResultsThe results demonstrated that treatment with endophytic fungi significantly increased the aboveground dry weight, root length, and tillering capacity of F. sinensis, and Cp78, Pe167, and Ta121 were selected for omics analysis due to their strongest growth-promoting effects, with a distinct hierarchical gradient in the complexity of growth-promoting mechanisms among the three genera: Trichoderma > Cladosporium > Penicillium. Further multi-omics analysis revealed divergent core mechanisms of the three genera. First, Trichoderma promoted growth via tryptophan metabolism (IAA synthesis), upregulation of hormone signal transduction genes/transcription factors, and enhanced biosynthesis of anti-disease metabolites (e.g., alkaloids). Second, Cladosporium activated the steroid biosynthesis pathway to produce brassinosteroid precursor substances, and promoted intracellular hormone transport and signal transduction by overexpressing signal transduction-related genes. Third, Penicillium primarily promoted plant growth by regulating key pathways involved in carbon cycling.
DiscussionThis study clarifies the genus-specific growth-promoting mechanisms of Ascomycete endophytes on F. sinensis, provides theoretical support and high-quality strain resources for developing microbial inoculants specific to alpine forages, and facilitates grassland restoration, with significant ecological and agricultural implications for alpine pastoral regions.