Plants and fungi are interdependently connected in nature, through interactions that are beneficial to both (mutualism, and decomposition of dead plant material by fungi) or detrimental to one partner (parasitism). Therefore, fungal and plant biology cannot be fully understood without studying them within the context of their symbiotic interactions. With the advent of new DNA sequencing technologies, it is becoming clear that the 100,000 known species of fungi represent only a tiny fraction of the estimated 5.1 million species of fungi present in nature. Amazingly, the largest fraction of this unknown fungal diversity seems to be hidden in healthy leaves of plants and lichens, as endophytic and endolichenic fungi. Endophytes are known to protect plants from pathogens, and enhance their resistance to abiotic stresses such as droughts and high temperatures. Most of these hyperdiverse endophytic and endolichenic fungi are classified within a group of filamentous Ascomycota fungi called the Pezizomycotina. The main aims of this research are to reconstruct a phylogeny (genealogical relationships) for the Pezizomycotina and link this evolutionary framework with a rich and diverse set of organismal data. The research will be complemented by diverse outreach activities, engagement of high school students in research, training of junior scientists in five states, and development of tools with potential applications for studying the evolution of species interactions across the life sciences. Accelerating the discovery of these hidden fungi also promises to provide a rich source of secondary compounds for new pharmaceutical and biocontrol products.
The objectives of this study are to fill the largest phylogenetic void in the fungal genealogy of life (the Pezizomycotina) and integrate diverse data layers with the emergent tree as a means to understand the evolution, ecology, and physiology of fungal-plant symbioses. Culture-dependent and independent methods will generate the largest sample of endophytic and endolichenic fungi to date, targeting diverse plants, lichens, macroalgae, and co-occurring microalgae and cyanobacteria in terrestrial, aquatic, and marine environments, with a focus on biotically rich but understudied bioclimatic zones. Efficient collecting and analytical pipelines will enable rapid integration of phylogenetic data from these new symbiotic fungi into the fungal genealogy of life, while novel biodiversity informatics tools will integrate existing multi-locus and phylogenomic frameworks with short sequence reads obtained with next-generation sequencing. Resulting evolutionary trees, greatly enriched by systematic sampling of currently unknown biodiversity, will be integrated with host and trophic spectra in three data layers (symbio-phylogenetic, eco-phylogenetic, and physio-phylogenetic), enabling for the first time novel insights from geographic data, abiotic and biotic factors, and the physiological traits that enable mutualistic interactions with plants on which most communities depend.
