Endophytic Fungi: Dimensions of Diversity Within Tropical Leaves

The foliage of tropical forests harbors diverse endosymbionts, including fungal endophytes. These fungi occur within healthy tissues and are increasingly appreciated as important, if cryptic, components of forest biodiversity. Endophytes shape leaf phenotypes, are influenced by leaf traits in turn, and contribute to plant responses to stress and natural enemies, and thus they are key to plant resilience and community dynamics. Here we summarize how foundational contributions by scientists at Barro Colorado Island (BCI), Panama, have shed light on endophyte ecology from local to global scales. We then provide an overview of more recent advances in the molecular biology and potential applications of endophytes in diverse settings. Together the body of research conducted at BCI and through the Smithsonian Tropical Research Institute has been key to discovering the diversity and ecological roles of these little-known symbionts, now understood to be fundamental aspects of “what it is to be a plant” in tropical forests.