The Viridin Biosynthesis Gene Cluster of Trichoderma virens and Its Conservancy in the Bat White-Nose Fungus Pseudogymnoascus destructans

Viridin group of furano-steroidal antibiotics are known to function as anti-fungal and anti-cancer agents, in addition to their roles as radio- and chemo-sensitizers. Discovered in 1945 as a metabolite of Trichoderma virens, viridins continue to receive significant attention of several synthetic chemists and clinicians as a very strong PI3 kinase inhibitor. However, till date, researchers have not been able to discover a single gene that is involved in viridin biosynthesis. In this study, we present the complete gene cluster for the biosynthesis of viridin in T. virens, and provide genetic evidence of its involvement in viridin formation. Also, we show that the same cluster is present in a distantly related fungus Pseudogymnoascus destructans that causes bat white-nose disease, which is leading to the devastation of the bat population in North America. Our findings, thus, pave not only the way for further research on the elucidation of the complete biosynthesis pathway and possible tuning of viridin production in the plant beneficial fungus Trichoderma virens, but also are expected to trigger investigations on the role of this gene cluster in pathogenicity of the devastating bat pathogen.