ME: Quantifying and Manipulating Seed Metabolic Networks

Michigan State University, East Lansing MI

Investigators

Abstract

Plant seeds are the world's most important agricultural product and the lowest cost biological source of carbohydrates, oils and proteins. An important goal of plant metabolic engineering is to develop chemical and nutritional production systems in seeds that are amenable to rational genetic engineering. To reach this goal, a quantitative understanding of fluxes through biochemical pathways is needed for seeds. This project will begin to provide such an understanding through analysis and engineering of the accumulation of storage oils in Brassica napus seeds. Three central questions about oilseed metabolism will be addressed: How do seeds cope with the CO2 generated during oil synthesis? By what pathways does carbon flow from sucrose to oil and storage proteins and how are these pathways influenced by availability of light? What is the source of reductant for fatty acid biosynthesis? These problems are interlinked by shared metabolic intermediates and pathways and the processes they represent must be coordinately regulated during seed development. This project will lead to a quantitative description of metabolic networks in a major agricultural production system, and to improved strategies for engineering changes in metabolism. The resulting progress in understanding, modeling and engineering seed metabolism and the interdisciplinary training of students and postdocs will help move plant metabolic engineering from the current hit and miss state toward a framework of rational design and analysis. This information will be crucial to expanding the use of plants as green factories that provide renewable and sustainable alternatives to petroleum and also aid nutritional improvements in the seeds that provide most of the world's food.