In contrast to the extensive knowledge available on plant metabolism, very little is known on how plants transport often toxic or highly reactive chemicals from their site of synthesis to where they are ultimately stored. Proper trafficking and storage of plant compounds (phytochemicals) is often a bottleneck in efforts aimed at the rationale engineering of plant metabolism. Thus, understanding the cellular and molecular mechanisms involved in phytochemical trafficking is of the utmost significance. The formation of anthocyanin pigments in Arabidopsis provides an outstanding system to investigate how phytochemicals are transported and sequestered inside plant cells. This research is geared by the hypothesis that anthocyanins first accumulate inside the endoplasmic reticulum, and that vesicles derived from this organelle transport these chemicals to the vacuole, where upon uptake, localize in sub-vacuolar structures. This project will first investigate the localization of anthocyanin biosynthetic enzymes and putative anthocyanin transporters on the endoplasmic reticulum. Then, the sub-vacuolar structures that accumulate anthocyanins will be characterized from the perspective of the proteins and anthocyanins that are part of them. Finally, using a combination of cellular markers and various genetic tools, the pathways by which anthocyanins move from the endoplasmic reticulum to the vacuole will be determined. Together, these studies will provide fundamental insights on the mechanisms used by plants to move phytochemicals within cells.
Broader Impacts This is an interdisciplinary proposal that uniquely integrates cell biology and biochemistry to address the fundamental biological problem of how plants manage the sub-cellular trafficking of phytochemicals. The implications derived from the studies proposed here are likely to have far-reaching consequences, providing insights into the formation of new cellular structures and impacting strategies for plant metabolic engineering. This could result in significant societal benefits, for example, benefiting the development of biofuel crops and improving the nutritional value of plant products. Beyond the standard classroom teaching and lab personnel training in which both PIs are actively involved, this project integrates research and educational training for students and postdocs in a singular way at the cutting-edge interface between chemistry and biology. By organizing workshops and conferences, such as the Gordon Kenan Graduate Research Seminars and the Gordon Conference in Plant Metabolic Engineering, the PIs have significantly bridged education and research, activities that will be continued during the duration of this project.
