Volatile compounds emitted by Plant Growth Promoting Fungi Tolypocladium inflatum GT22 alleviates copper and pathogen stress
The intricate interactions between plants and microorganisms have garnered substantial scientific interest. While previous studies have highlighted the potential influence of various fungal volatile compounds(VCs) on plant growth and development, the precise mechanisms underlying this modulation still need to be discovered. In this study, we discovered that fungal volatile organic compounds from the soil-borne fungus Tolypocladium inflatum GT22 enhance the growth of Arabidopsis. Remarkably, following the priming of Arabidopsis with GT22 VC, it displayed an enhanced immune response, thereby mitigating the detrimental effects caused by both pathogenic infections and copper stress. Transcriptomic analyses of Arabidopsis seedlings treated with GT22 VCs revealed the differential expression of 90, 83, and 137 genes after 3, 24, and 48 hours of volatile exposure, respectively. These responsive genes are involved in growth, hormone regulation, defense mechanisms, and signaling pathways. Notably, the induction of genes related to innate immunity, hypoxia, salicylic acid (SA) biosynthesis and camalexin biosynthesis by GT22 VCs were reported. Among the VCs emitted by GT22, limonene is particularly noteworthy. Arabidopsis seedlings exposed to limonene exhibited not only growth promotion effects but also alleviation of copper stress, indicating that limonene may play a role in the interaction between GT22 and plants. Overall, the findings of this study provide evidence supporting that fungal VCs can promote plant growth and enhance both biotic and abiotic tolerance. Furthermore, our results suggest that seedlings exposed to T. inflatum GT22 VCs holds promising potential for harnessing beneficial effects to improve crop productivity. Overall design: To investigate the molecular mechanisms triggered by T. inflatum GT22 VCs in Arabidopsis, the transcriptomic analysis was performed. RNA-seq data of 3, 24, 48 hr T. inflatum GT22 VCs treatment in Arabidopsis thaliana was analyzed.