Lipid Network Flux Cartography for Quantitative Control of Oil Accumulation and Composition

植物油是人类生活的重要组成部分，被用作食品、化学品和燃料。据预测，到2040年，世界植物油产量必须翻一番才能满足不断增长的人口的需求，如果植物油将越来越多地取代石油作为燃料和化学品，则需要更大幅度的增长。为了满足这种不断增长的需求，我们需要更好地了解控制植物油生物合成和油成分的代谢反应。本项目的目标是定量描述关键油和膜脂生物合成蛋白对模式植物拟南芥中重要中间体进入油或膜脂的通量的控制。为了培养下一代劳动力，pi将把他们的研究纳入本科生、研究生和博士后的培训中。由于植物油是一种宝贵的可再生资源，可用于食品、燃料和化学品，这项研究将进一步提高我们指导植物脂质代谢网络生产设计油的能力。在不同的植物物种中，是什么控制着新生二酰基甘油进入脂质生物合成网络的替代分支的通量，目前还知之甚少。pi假设一个关键的控制点是新合成的二酰基甘油在磷脂酰胆碱和三酰基甘油合成之间的分配。本研究的目的是：1)揭示非冗余二甘油酯乙酰转移酶1和二甘油酯乙酰转移酶2三酰基甘油合成酶在直接产油和膜脂合成之间的新产二酰基甘油分配中的作用；2)表征磷脂酰胆碱合成酶在脂质生物合成网络中重新分配二酰基甘油的作用；3)建立拟南芥甘油脂通量调控的定量动力学模型；4)探索蛋白质：蛋白质相互作用表征构成控制二酰基甘油通量的脂质代谢复合物的分子成分。上述方法将与计算机建模相结合，通过植物脂质代谢网络产生代谢物通量控制的定量描述，然后可以指导设计植物油的生产。

Plant oils are a vital part of human life and are utilized as food, chemicals, and fuels. It is predicted that world output of plant oils must double by 2040 to meet the needs of the growing human population, and even larger increases are needed if plant oils will be used to increasingly replace petroleum as fuels and chemicals. To meet this rising demand we need a better understanding of the metabolic reactions that control plant oil biosynthesis and oil composition. The goal of this project is to quantitatively describe the control exerted by key oil and membrane lipid biosynthetic proteins over the flux of vital intermediates into either oils or membrane lipids in the model plant, Arabidopsis. To prepare the next generation workforce the PIs will incorporate their research into training of undergraduate and graduate students and a post-doctoral fellow. Since plant oils are valuable renewable resources used for food, fuels, and chemicals this research will further our ability to guide plant lipid metabolic networks for the production of designer oils.Little is known about what controls the flux of de novo diacylglycerol into alternative branches of the lipid biosynthetic network in different plant species. The PIs hypothesize that a crucial control point is the partitioning of de novo synthesized diacylglycerol between phosphatidylcholine and triacylglycerol synthesis. The aims of the research are: 1) deciphering the roles of the non-redundant diglyceride acetyltransferase 1 and diglyceride acetyltransferase 2 triacylglycerol synthesizing enzymes in partitioning of de novo diacylglycerol between direct oil production and membrane lipid synthesis; 2) characterize the role of phosphatidylcholine synthesis enzymes in partitioning of de novo diacylglycerol into different branches of the lipid biosynthetic network; 3) develop quantitative kinetic models for the control of glycerolipid fluxes in Arabidopsis; and 4) explore protein:protein interactions to characterize the molecular components that make up the lipid metabolic complexes that control diacylglycerol fluxes. The above approaches will be combined with computer modeling to produce a quantitative description of the control of metabolite fluxes through the plant lipid metabolic network that can then guide the production of designer plant oils.