Collaborative Research: Extending leaf functional trait ecology to leaf symbionts

Tulane University, New Orleans LA

Investigators

Abstract

Abundant and diverse fungi live inside healthy leaves of all trees. These 'fungal endophytes' (endo, inside; phyte, plant) can be important in enhancing plant health under stressful conditions. However, the factors that shape the diverse communities of endophytes found in different plant species are not well understood. This project's overall goal is to integrate fungal endophytes into our understanding of tropical plant ecology, with a special focus on the relationships among leaf traits, plant productivity, and the ability of plants to defend against insects and pathogens that attack leaves. Improving our understanding of fungal endophytes is important since they influence plant productivity and resistance to environmental stresses such as drought and disease, including for plants of economic importance. Results will facilitate use of endophytes in mitigating plant responses to a rapidly changing world, with potential applications in sustainable agriculture and forest management. This project will also support the training of undergraduate and graduate students in interdisciplinary research, including students of under-represented groups, provide mentored research experiences for K-12 teachers and for high school students, and contribute to public outreach. In the context of tropical forests, where leaf traits and endophytes are highly diverse, this project will test the hypotheses that (1) endophyte communities in leaves vary in relation to leaf traits associated with growth vs. persistence strategies; (2) endophytes will influence leaf and plant functions; (3) contribution of endophytes to plant defense will vary as a function of leaf traits; and (4) understanding growth vs. persistence strategies of plants can be informed greatly by integration of these foliar symbionts. The research approach involves field observations and experiments as well as bioassays. A field experiment is planned where endophyte communities are manipulated in 12 focal species. Additionally, leaves from these same 12 species will be introduced to leaf cutter ants to test whether longer lifespan species are less attractive to leaf cutter ants, and whether this will be mediated by endophyte load. Furthermore, pathogens will be introduced to the 12 focal species to assay if damage will be lower in leaves with high endophyte loads.