2022 Undergraduate Research Showcase

Document Type

Student Presentation

Presentation Date


Faculty Sponsor

Dr. Leonora Bittleston


The leaf tissues of plants host a myriad of microbes that can influence plant health. Our research investigates the leaf microbiome of sagebrush (Artemisia tridentata), a foundational species within its ecosystem. The sagebrush ecosystem is vulnerable to many anthropogenic stressors such as climate change and increased fire frequency. Discovering the community dynamics of the microbes associated with sagebrush leaves can inform our understanding of their role in sagebrush health and potentially lead to novel methods for ecosystem management. In this study, we focused on Aureobasidium pullulans, a pigmented yeast-like fungus identified on our sampled sagebrush leaves via culturing and DNA sequencing. Here, we seek to quantify abundance of A. pullulans on the sagebrush leaf microbiome and determine how environmental and temporal factors may influence both its absolute and relative abundance. Using photos of confirmed A. pullulans for reference, we used image data of previously cultured samples to morphologically match and record all instances of A. pullulans from March-October 2021. Weather data variables were acquired from the Dry Creek Lower Weather Station near Boise, Idaho, adjacent to our sagebrush sampling site. We found a negative correlation of the microbe’s absolute abundance with both air temperature and precipitation, but no correlation with wind speed. No significant differences were found for relative abundance across plants or leaf type. Significant differences were found in both relative and absolute abundance of A. pullulans across sampling dates. These results demonstrate that time and environment both influence abundance of A. pullulans within the microbial community of sagebrush leaves. This study sets the stage for future research into understanding the functional role of A. pullulans in the sagebrush leaf microbiome, and by extension, its impact on the sage-steppe ecosystem.



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