The project focuses on chemical studies of mycoparasitic/fungicolous fungi that attack and colonize long-lived physiological structures (e.g., stromata and other fruit bodies) produced by other fungi in nature. The central underlying hypothesis is that invasion by fungal colonists often involves antibiosis toward the host, and therefore, such colonists may be valuable, underexplored sources of natural antifungal agents. Thus far, over 2,300 cultures have been isolated from over 600 specimens of stromata and polypores collected from northern forested habitats (Illinois/Wisconsin), subtropical latitudes (Georgia/Florida), and diverse microclimates found on the island of Hawaii. These collections contain considerable biodiversity, and include representatives of many new or relatively unexplored taxa, as well as known mycoparasitic species. Chemical studies will focus on as-yet unexplored active leads from the Hawaiian collection. A second objective follows from the discovery that isolates of the widespread corn endophyte Acremonium zeae commonly produce a set of intriguing natural products (pyrrocidines). These findings have led to the initiation of exploration of a collection of ca. 200 corn endophyte isolates, representing a variety of taxa, in search of other new fungal metabolites that show antagonistic effects against fungal competitors.
With this award, the Organic and Macromolecular Chemistry Program is renewing support for the work of Professor James B. Gloer, of the Department of Chemistry at the University of Iowa. With his collaborators, Patrick F. Dowd and Donald T. Wicklow, of the U.S. Department of Agriculture, Professor Gloer is isolating new organic compounds from fungi, with these studies guided by a hypothesis that parasitic fungi may be rich sources of new chemical structures given their need to develop chemical control over their hosts. Many new bioactive natural products have been discovered through studies of fungal cultures. This unique, growing body of work will ultimately enable efforts to correlate host, geography, and climate with biological and chemical diversity. The resulting data could prove useful in guiding future selection of sources. Antifungal agents are of potential practical value to society in agriculture and medicine, and can also be valuable as tools to assist in discovery of new modes of action. Findings from this project are also expected to contribute to fundamental scientific knowledge in other disciplines, including fungal ecology, taxonomy, biodiversity, crop/food science, and evolutionary biology.
