Regulation of plastid metabolism in higher plants

点击翻译按钮获取中文摘要

The objective of this proposal is to improve our fundamental understanding of the regulation of plastid metabolic pathways in higher plants. In particular, the research program will investigate the regulatory mechanisms governing tocopherol biosynthesis in oilseed plastids, the organization of the pathway within developing organelles, and its relationship to other major metabolic pathways. Tocopherols and tocotrienols are an important group of lipid-soluble antioxidants synthesized exclusively in photosynthetic tissues, with many beneficial properties, both with respect to human health (e.g. vitamin E activity), and within the food industry as stabilizers and preservatives, and are therefore a valuable by-product of major oilseed crops such as soybean (Glycine max L.). We plan to take multi-disciplinary approaches to understanding the regulation and organization of tocopherol and tocotrienol biosynthesis both in leaf chloroplasts of Arabidopsis (a genetically amenable plant and also an oilseed) and photoheterotrophic plastids of developing oilseeds such as soybean. Specifically, these techniques will be employed to examine the components of the pathway within plastids (inner membranes, and sub-plastidial compartments such as the plastoglobules), and identify other, as yet undiscovered, proteins interacting with components of the tocopherol biosynthetic pathway, e.g. regulatory factors or elements of signal transduction cascades and intra-plastidial trafficking systems. This research will provide important insights into the mechanisms governing the control and regulation of important metabolic pathways in the plastids of higher plants, and contribute to engineering crops with improved nutritional value and enhanced high-value bioproducts.