In natural environments, plants are in constant contact with a variety of microbes, yet most studies investigate the impact of microbial symbionts one at a time. While some microbes are categorized as mutualists, most vary along the mutualism-parasitism continuum and may act as a mutualist, parasite and/or commensal throughout a plant’s lifetime, depending on environmental conditions. Two such categories of microbes ubiquitous to the dwindling North American prairie are arbuscular mycorrhizal fungi (AMF) and fungal leaf endophytes (FLE). AMF are classically considered mutualists, while FLE are often divided into pathogens and non-pathogens. Though these microbes are often co-occurring, their combined impacts on plants are rarely investigated. These fungi may provide synergistic benefits to plants or compete for photosynthates or alter/activate plant hormones. Even when the impacts of these symbionts are studied individually, most researchers focus on growth traits (ie. biomass, height) ignoring the range of benefits fungal mutualists can provide for biotic interactions such as herbivore resistance and defense and pollinator attraction, via changes in volatile organic compound profiles. These multi-partite, nested symbioses can therefore affect the plant’s ability to interact with insect mutualists and enemies. GEMS trainee Ilana Zeitzer proposes an experiment to investigate the individual and combined impacts of AMF (Claroideoglomus spp.) and field collected, growth promoting FLE on the common prairie plants Andropogon gerardii, and Monarda fistulosa.