From Function to Omics: Endophytic Beauveria bassiana Promotes Maize Growth by Activating Phytohormone Signaling Pathways under Elevated Carbon Dioxide
Several entomopathogenic fungi (EPF) species can colonize and establish symbiotic relationships with plants as endophytes, which affects crop growth under elevated carbon dioxide (eCO2) concentrations. However, how EPF facilitates plants under eCO2 is poorly understood, especially at the transcriptional and metabolic levels. Here, the authors examined the effects of a widely used EPF, Beauveria bassiana, on maize growth under eCO2, and how it regulates enzyme activity and endogenous hormone metabolism, using transcriptomics and metabolomics. A significant increase in maize growth, as well as associated enzyme activity and hormones, under eCO2, following B. bassiana colonization, was observed. Omics analyses indicated that these effects may be attributed to the activation of primary metabolic pathways (ZMA01100) and secondary metabolite biosynthesis (ZMA01110), which have been demonstrated to influence plant hormone production and enzyme activity. The finding suggests that B. bassiana colonization modulates plants growth under eCO2 via regulation of the expression of related genes, and in turn, enzyme activity and hormone metabolism. The findings of the present study offer a theoretical foundation for elucidating the interactions between EPF and plants under climate change.