Donald Danforth Plant Science Center

Summary: Oils Are the Most Energy Dense Product of Plant-based Photosynthesis, With Twice the Energy Content of Carbohydrates. in Most Cases, Oils Accumulate in Seeds. Seed-set Occurs Only Over the Last 1/3RD of the Life Cycle. Therefore, Setting Seeds Is Not the Most Efficient Way to Capitalize on Sunlight-powered Carbon Assimilation for Products Especially With Increasingly Challenging Environmental Conditions. an Appealing Alternative Is to Make Lipids in Leaves. Leaf Biomass Is Made Throughout the Life-cycle and Lipids Can Be Easily and Cost-effectively Extracted From Leaves. We Propose to Study Engineered Tobacco With High Levels of Lipids in Leaves (oil as 30% of Biomass). Recent Efforts Have Enabled Low Percentage Lipid Production in the Leaves of Sugarcane, Potato, Arabidopsis, But Nothing Comparable to the 30% Oil in Leaves of Tobacco. Therefore, Understanding How Tobacco Metabolism Adapts to the High Demands of Lipid Accumulation in Engineered Leaves Under Challenging Environments Will Enable Further Engineering Efforts in All Crops. the Aims of This Project Are: 1) Assess Dynamics of Growth and Photosynthesis in Oil Producing Leaves Under Stress to Characterize Tradeoffs Between Oil Production and Photosynthetic Membrane Maintenance; 2) Characterize the Mechanistic Impact of Acyl Flux Toward Oil Rather Than Photosynthetic Membranes on Photosynthetic Hardware and Function; 3) Assess Carbon Partitioning of Leaf Acyl Flux Plasticity to the Combined Demands of Oil Accumulation and Membrane Remodeling in Response to Adverse Environments; and 4) Develop Models of Leaf Dynamics and Response to the Environment to Identify Key Metabolic Reactions for Accumulating Leaf Oils.