Divergent epigenetic profiles from two differentially impacted wild populations of estuarine cordgrass (Sporobolus alterniflorus)

Abstract

The effects of urbanization on watershed ecosystems present critical challenges to modern survival. Organisms in urbanized areas experience high rates of evolutionary change, but genetic adaptation alone cannot mitigate the rapid and severe effects of urbanization on biodiversity. Highly resilient, foundation species are key to maintaining an ecosystem’s integrity in the face of urban stressors. However, the rapid collapse and disappearance of watershed ecosystems calls into question the extent to which we can rely on such species for their services. Our research investigates the molecular mechanisms by which the foundation ecosystems provider, Sporobolus alternifloru s, adapts to life in an urbanized environment. To elucidate these mechanisms, we quantified changes in global DNA methylation (% 5-mC) as a result of acute heat stress. Specimens from two differentially impacted populations across an urban to suburban geographical transect formed the basis of this study. These two populations of Sporobolus alterniflora exhibit inverse global DNA methylation patterns when exposed to the same acute heat stress. Our findings suggest that epigenetic mechanisms, such as DNA methylation, control rapid and transient adaptation, in the form of differential stress responses, to distinct environment challenges.