Shifting Costs and Benefits of Systemic Endophyte Interactions With Native Grass Hosts

Arizona State University, Scottsdale AZ

Investigators

Abstract

Project Summary Endophytes are fungi that live internally in plants but do not cause disease. Instead, endophytes are thought to benefit the plant by increasing resistance to drought, herbivores, and seed predators, pathogens and root feeders and increasing germination rates, nutrient uptake, and competitive abilities. Endophytes are found in all plants, including agronomic crops and turf grasses. They are used in turf grasses to increase performance of grasses, but may also cause harm livestock because of their toxic effects. However, little is known about the role of endophytes in native grasses. The benefits of endophytes are often not the same as in agronomic grasses. Our research seeks to determine the costs and benefits of asexual, seed borne endophytes in the genus Neotyphodium in two widespread SW native grasses, Arizona fescue and sleepy grass. Our goals are to experimentally test the cost and benefits of Neotyphodium infection depending on plant and endophyte genotype and environment. We will implement two major field experiments that control plant genotype and endophyte infection, soil moisture levels and herbivory by invertebrates and vertebrates. Our results will provide insights into basic interactions between endophytes and their host grasses, and may have important applied aspects related to forage grasses.