Most plants cannot grow when soil temperatures reach levels that are above 100 °F. However, in Yellowstone National Park soil temperatures can be much higher in the geothermal areas, and occasionally plants can be found growing in soils in temperatures up to 125 °F. These plants have a fungus, called Curvularia protuberata that grows in them, and they cannot grow in these soil temperatures without the fungus. The fungus itself is infected with a virus, and the virus also is required for the whole thermal tolerant system of plant, fungus and virus (called a symbiosis) to survive. However, the interactions between the virus and fungus in this system and other microbe-interacting systems in the environment are very poorly understood. A crucial key to the understanding of adaptive changes in response to environmental stress is missing. In addition, very few beneficial viruses have been described or studied. <br/><br/>The long-term goal of the research is to understand how plants and mutualistic microorganisms interact with one another and their surrounding environments to acquire stress tolerance. This project will study the physiology and genetics that define the mechanism of this interaction. Its goals are to: <br/><br/>1) Identify and characterize additional plant-fungus-virus symbionts that are thermotolerant; <br/><br/>2) Identify the genetic expression and metabolite changes of plants and fungi involved in the three way symbiosis during heat stress; <br/><br/>3) Study how the proteins from each organism interact; and <br/><br/>4) Test the genes discovered for their effects on tolerance to heat. <br/><br/>With changes in the Earth's climate and the need to produce more and more food for the increasing human population, learning how plants adapt naturally to environmental changes such as are seen in Yellowstone National Park will provide tools with potential application to agriculture.