Plants must respond to environmental cues like light to survive and flourish. Light sensors enable plants to react to sunlight by triggering photosynthesis, UV sunscreen protection, and appropriate light-activated growth and development (photomorphogenesis). The plant UVR8 UV-B photoreceptive system initiates stress responses to promote survival using a novel tryptophan pyramid as the intrinsic chromophore, then couples signaling interactions to trigger massive gene expression changes. This light-activated system, investigated by the application of state-of-the-art biophysical techniques and a transdisciplinary approach will enable a mechanistic understanding of a prototypic biological response pathway. Building on the first crystallographic and solution structures of UVR8 determined in the Getzoff lab, this research will integrate structural biology expertise in X-ray crystallography and solution scattering; building of comprehensive biochemical models; spectroscopy to assay light-activated mechanisms and phenotypes; and strategic cross-disciplinary collaborations with plant biologists to inform and be informed by molecular genetics in plants. The results will provide plant biologists with a molecular-level appreciation of photomorphogenesis. Characterization of UVR8 partners will provide information on structure, interactions and activities of the beta-propeller WD40 domain, one of the top-ten most abundant folds in eukaryotic genomes. The resulting mechanistic understanding of how plants respond to sunlight provides insights into how crops will react to climate change and to increased radiation resulting from depletion of atmospheric ozone.
Broader Impacts: This project will bring science into the classroom by providing genuine research experience to high school students. Learning molecular biology techniques in their own lab, these students participate by making structure-based mutants; growing protein crystals and seeing tangible outcomes relevant to environmental problems. Thus, students actively apply the scientific method and learn how to test biological hypotheses experimentally. This project will facilitate continued PI involvement in the interdisciplinary graduate program and support participation of underrepresented groups in Science, Technology, Engineering and Mathematics. In the lab, students and post-doctoral fellows will be trained in contributing to interdisciplinary, international collaborations and mentoring junior interns in projects involving the UVR8 plant photoresponse system.
