97 Comparative Transcriptomic Assay of Phellinus Tremulae Isolates to Identify the Genetic Responses of Environmental Stress

Faculty Mentor: Bryn Dentinger (School of Biological Sciences, University of Utah)

Saprotrophic fungi are a diverse ecological group that can breakdown organic matter to obtain carbon. Due to their metabolic processes, they play an essential role in nutrient cycling within the microbial soil community. Despite the importance of saprotrophic fungi, little is known about their response to climate change. Mimicking real world situations and using transcriptomic analysis can help us characterize what genetic mechanisms saprotrophic basidiomycetes use to respond to environmental changes. This research utilizes cultures of a common saprotrophic fungus, Phellinus tremulae, which is known to cause white trunk rot and parasitize aspen trees. We have conducted a culture growth assay where isolates are grown under varying conditions that mimic ecological stressors, to induce a stress response in the saprotrophic fungus. We then extracted and sequenced mRNA from the cultures to identify the genes that are differentially expressed in the presence or absence of an ecological stressor. Specifically, we analyzed the impacts of heat stress, high and low pH, and recalcitrant carbon compounds as the sole carbon source. Differential gene expression analysis of these conditions revealed that environmental stress, particularly living stress, had a greater impact on isolates compared to nutritional stress. Future work includes identifying if these fungi utilize these genes to adapt to environmental stress in their natural habitats and what cellular functions are involved with adapting to these stressors.