Two-thirds of the known 250,000 vascular plant species live in mutualisms with arbuscular mycorrhizal fungi (AMF) that grow in association with roots. AMF acquire sugar from plants while increasing nutrient or water uptake or providing protection from heavy metals found in some soils. Most individual plants support more than one species of AMF. Although all AMF species were once thought to provide similar functions, there is growing evidence that different AMF species perform different functions and that the importance of any one species may be conditional on soil environment and on the identity of co-occurring fungi. This project will conduct experiments with plants, AMF, and soil from natural serpentine grasslands to determine whether there are functional differences among AMF species. The function of AMF will be measured by their effect on plant growth and plant nutrient and metal content. This project will also develop and test an innovative new approach to measuring AMF abundance, based on fluorescent-labeled antibodies that can be created to label the species uniquely. This technique could prove transformative to the study of plant and AMF ecology in natural and agro-ecosystems. Serpentine grasslands are a globally rare and threatened ecosystem with soils naturally high in toxic heavy metals. Understanding the role AMF play in helping plants cope with heavy metals will be helpful in the restoration of both serpentine sites and polluted soils. This project will also support the research training of a doctoral student in plant ecology.
