Examining Temporal, Host, and Environmental Dynamics of the Sagebrush Leaf Microbiome

Sagebrush ( Artemisia tridentate ) is a woody shrub native to grassland and sage-steppe ecosystems throughout the Intermountain West. In addition to being integral to healthy ecosystem functioning, sagebrush is vulnerable to anthropogenic disturbances such as fire, which has been increasing in frequency and intensity in recent years. Plants host a variety of microbes such as bacteria and fungi that can influence plant health, physiology, and defense properties. Previous phyllosphere research has focused on sequencing bacterial communities, primarily of leaf surfaces. The microbiome of sagebrush leaves has never been examined. Here, we seek to characterize the sagebrush leaf microbiome and the potential influences of time, host factors, and environment on microbial community structure. On three separate trips spanning June 3 ^rd to July 2 ^nd , 2021, we sampled six sagebrush shrubs near the Dry Creek Trailhead northeast of Boise, Idaho and processed both epiphytic (leaf surface) and endophytic (internal leaf tissue) communities of sagebrush leaves for microbe culturing. Cultured communities were isolated by morphospecies and microbial community metrics were analyzed against time, environment, and host characters. Statistical analyses were conducted in R, using Shannon’s Diversity Index and Bray-Curtis Dissimilarity metrics. Preliminary results show significantly higher species richness of epiphytes when compared to endophytes, and significantly higher epiphytic diversity in early June when compared to July. Continued research on the sagebrush leaf microbiome as it relates to time, environment, and host factors opens the door to potential future work on manipulating microbial community structures to enhance favorable plant properties, which may aid in sagebrush conservation and ecosystem restoration in the future.