PS 5-65 - Plant Trait Variation and Epigenetic Variation of Grindelia squarrosa

Abstract: The sagebrush ecosystem is one of the most integral and expansive ecosystems in the U.S., but has recently come under threat due to global climate change, overgrazing, habitat destruction, and other anthropogenic disturbances. This type of destruction over such a substantial portion of the country could result in severe loss of both biodiversity and ecosystem services. Restoration of sagebrush ecosystems is a difficult and expensive process due to high plant mortality and seed collection difficulty. However, failure to successfully restore sagebrush ecosystems is even more expensive; therefore, ecological restoration practices with higher success rates are crucial. Phenotypic plasticity and adaptation to local environments are crucial factors that help determine the success of ecological restoration. Further, epigenetic changes allow for the possibility of heritable adaptation, resulting in populations well-adapted to their local environment, but not necessarily global environments. Information in this regard is useful for addressing the issue of local seed collecting vs. purchasing seeds from companies that harvest them. As communities become geographically isolated, further genetic differences may appear, resulting in less successful restoration when other ecotypes are used. Our study involves a functional trait approach that allows for the determination of these factors in Grindelia squarrosa. This native species is commonly found in sagebrush habitat ecosystems and is a species of importance in terms of ecological restoration. We obtained seeds from three populations of Grindelia squarrosa, across its range, and grew them in wet and dry conditions in a growth chamber. This allows for analysis of responses to drought stress, a frequent problem that sagebrush ecosystems contend with. In order to analyze these factors, genetic data, leaf trait data were collected as well as CO2 response curves and epigenetic variation. Here, epigenetic variation is defined as modifications, such as DNA methylation, made to the genome in response to the environment. Preliminary data show significant phenotypic differences in leaf traits that can be attributed to accession, watering treatment, and interactions that may be an indication of local adaptation. These results contribute to what we know about this species and can help inform restoration seed sourcing protocol in sagebrush habitat and predict plant response to climate change.