This project investigates the diversity, evolution and ecological functions within a diverse lineage of fungi, the Mucoromycota. These fungi are industrially important for lipid production and as biofertilizers in agricultural systems. They have co-evolved with plants through innovations of their growth within plant tissues, and are implicated in the successful invasion of land by plants. Many of the fungi in this group are plant growth promoters and carry within their cells bacterial endosymbionts belonging to lineages of bacteria that are known only from these fungi. Some of these bacteria produce potent toxins. This research investigates the role of these endobacteria on their fungal host's growth and metabolism, and the impact of endobacteria on fungal-plant interactions. It will produce a culture collection and database of these fungi available to other scientists. Reference DNA barcodes and genome sequences from these collections will be integrated into sequence-based classifiers as a resource for the broader community. A short-course on "Computational Thinking in Biodiversity and Evolutionary Research", and studies to determine how traditional agriculture and cultural practices impact Mucoromycota fungi in the soil are part of the project. Overall, this research will provide diverse and cross-disciplinary education, training, and outreach to postdocs, graduate and undergraduate students.
The researchers will compare and analyze entire genomes to identify symbiosis traits that have co-evolved in plant-fungi-bacteria partners, and will assess the impact of bacterial endosymbionts on the function of their fungal host and its interaction with plants through metatranscriptomics. Changes in host plant phenotype, metabolome, transcriptome, and resilience to abiotic stress will be studied in experiments designed to test genetic traits in the host, fungi and bacteria. The phylogenetic dimension will integrate evolution and genomics to provide a robust phylogenomic framework and new computational tools for estimating co-evolutionary and horizontal gene transfer processes between Mucoromycota and their bacterial endosymbionts. The genetic dimension will apply genomic and metatranscriptomic studies of plant-fungal-bacterial symbionts, selected with guidance provided by the phylogenomics, to identify critical genes involved in symbiotic interactions. The functional component will dissect the role of candidate genes for plant host fitness in the context of different plant-fungal/bacterial partners and abiotic stressors. Together this integrated research will foster interdisciplinary collaborations to provide novel insights into the diversity, evolution and functioning of tripartite multi-kingdom symbiosis.