CRUI: A Multidisciplinary Test of Mutualistic Benefits Fungal Endophytes Provide Their Host Plants

Hope College, Holland MI

Investigators

Abstract

Fungi that live within grasses form a mutually beneficial association (mutualism) in which both the fungus and the grass benefit. Yet, the benefits to the grass may vary depending on the specific fungal species. We predict that the strength of the mutualism will depend upon the method by which the fungi reproduce. Fungi that reproduce by infecting seeds of their hosts are expected to be strong mutualists. In contrast, those that reproduce through spore production are expected to be weak mutualists or perhaps not even mutualistic with their hosts. In this project, five investigators from 3 disciplines and 2 institutions will use a multidisciplinary approach to determine if these fungi follow these predictions. One investigator (Bultman, at Hope College) will test if wounding of plants induces resistance to herbivorous insects through alkaloid production. This will be done using a variety of fungal species exhibiting different reproductive methods. These experiments will be coupled with molecular investigations of the regulation of alkaloid biosynthesis genes by Schardl (at the University of Kentucky) and Bultman. In addition to protection from herbivory, the fungi may enhance the drought tolerance of their plant hosts. Swarthout (Hope College) will test if drought tolerance is due to differential efficiency of enzymes utilized in photosynthesis, by comparing drought tolerance in fungally-infected vs. uninfected plants using a variety of grass and fungal species. Brown (Hope College) will use analytical chemistry methods to determine alkaloid concentrations in all experimental plants and correlate these concentrations to the observed effects. Andersen, a mathematician, and Bultman will collaborate to determine how the fungi affect plant fitness within a multitrophic level context through building theoretical models and empirically testing them with field experiments. The proposed work will address gaps in our general understanding of the ecological roles of fungi. The proposed project will have several broader impacts that go beyond the intellectual contributions described above. It will provide cutting-edge, multidisciplinary training in ecological research to 7-8 undergraduate students each year. Through a partnership with a local community college, 2 minority students annually will be involved in summer research at Hope College. Furthermore, a laboratory module for an interdisciplinary course in Mathematical Biology will be developed from the ecological modeling component of the proposed research. A post-doctoral researcher will also gain undergraduate teaching opportunities each year through financial support from Hope College.