How adaptable are Arctic organisms? The prevailing belief is that the severe cold, short growing seasons, high ultraviolet (UV) light exposure, and other environmental conditions not only limit which plants and animals can survive in the Arctic, but constrain their ability to evolve and adapt to current and future conditions. This is a timely subject given the current global climate crisis. PI Whittall (Santa Clara University) and Co-PI Carlson (University of Alaska Anchorage) are addressing this central question by using Arctic mustard species that exhibit variation in their flower colors (purple and white). This variation provides the raw material for evolutionary change and suggests Arctic genomes may actually be more dynamic than previously thought. These flower color differences may represent adaptations to pollinators based on the long-standing assumption that the purpose of flower color is to attract pollinators. Alternatively, the same pigments that paint flowers are also critical for a plant's ability to respond to environmental challenges such as cold, drought, and UV-exposure (the same environmental stresses that increase in the Arctic). Whittall and Carlson will study mustard populations along a latitudinal gradient into the Arctic where pollinators are increasingly scarce and the aforementioned challenging environmental factors increase. Whittall and Carlson, along with undergraduate and graduate students, plan to document the importance of pollinators and environmental factors in determining flower colors. By choosing mustard species, they will be able to use newly developed genomic tools, allowing them to survey the entire genome for differences between plants of different flower colors. Broader impacts of the research include increased insight into gene expression, and an understanding of how easily Arctic genomes can evolve (at least in these mustards). An additional component of the project will involve the creation of a summer-intensive undergraduate course entitled, "Arctic Biology: From Ecology to the Genome" where Santa Clara University students will study alongside University of Alaska students both in the Arctic, then back at Santa Clara University.
