Metabolomic and transcriptomic analysis of the controls on carbon partitioning into TAG reserves in oilseeds

油籽中碳分配到 TAG 储备控制的代谢组学和转录组学分析

• 批准号: BB/D006856/1
• 负责人: Ian Graham
• 金额: $ 53.99万
• 依托单位: University of York
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FD006856%2F1
• 关键词: Metabolomic; transcriptomic; analysis; controls; carbon

Plant oils supply about 25% of the calories in our diet. Increased consumption of oils and fats in the human diet is regarded as unhealthy, as it leads to obesity. However, the composition of plant oils influences whether they are beneficial or detrimental to human health. For example, there is evidence that consumption of long chain polyunsaturated fatty acids (LC-PUFAs), which are mainly supplied in our diet from fish oils, can improve our metabolism of fats in a beneficial way. In addition to their use as foodstuffs, plant oils are becoming increasingly important as replacements for petrochemicals in a wide range of industrial applications such as in the production of alternative fuels and lubricants. Despite the obvious uses and benefits of plant oils, we do not fully understand what controls oil yield and composition in agricultural crops. In these crops, the oils are produced in seeds. Therefore, in order to understand and optimize oil production in plants, we need to understand how oils are produced and stored in seeds. Oils in seeds are stored as triacylglycerols (TAGs), which are made up of three fatty acid molecules linked to glycerol. For many years, plant scientists have studied the biochemistry of TAG synthesis in oilseeds, with the aim to understand what metabolic pathway is responsible for TAG accumulation, and how it is regulated. However, it has become apparent that the process of TAG synthesis is only one component of overall lipid metabolism in plants, such that there are several competing pathways for the biochemical intermediates that are required to make oils. In addition, the picture is further complicated by recent work that has shown that there are multiple biochemical routes for TAG synthesis, and that TAG breakdown (catabolism) probably occurs at the same time as synthesis. Using molecular genetics approaches, researchers have identified many of the genes and metabolic intermediates that are important in lipid synthesis in plants. However, in order to understand how TAG synthesis is specifically regulated in oilseeds, we need to evaluate which genes and metabolites are primarily or specifically involved in TAG metabolism and which are involved in other areas of lipid metabolism. To answer this question, we plan to grow and harvest seeds from the model oilseed plant Arabidopsis at different developmental stages where TAG synthesis is known to be up- or down-regulated. There are hundreds of existing datasets that show how global gene expression (the transcriptome) varies over these developmental stages, and we plan to mine these data to find genes that show correlations with TAG synthesis. We also plan to generate some of our own transcriptomic data using Arabidopsis mutants where TAG synthesis is altered. Analysis of this data will uncover additional genes that may be important in regulating TAG synthesis. In order to correlate changes in gene expression with actual TAG synthesis during seed development, it is important to know how much TAG is present at any one stage, what the fatty acid composition of this TAG is, and how other lipid-related biochemical intermediates change in concentration. In addition, it is necessary to monitor how apparently unrelated biochemical pathways are changing, as some of the metabolites in these pathways may be indirectly regulating TAG biosynthesis. All these measurements can be accomplished using metabolomics, where the biochemical composition of small molecules is measured using a range of analytical techniques. Arabidopsis mutants that are deficient is specific lipid metabolism pathways will be selected for metabolome analysis, in order to understand how these pathways are linked to TAG synthesis. The results of this research will improve our understanding of lipid metabolism in plants, which will ultimately enable us to improve oil yields and the fatty acid composition of plants for dietary and industrial uses.

植物油提供了我们饮食中约25%的卡路里。在人类饮食中增加食用油和脂肪被认为是不健康的，因为它会导致肥胖。然而，植物油的组成影响它们对人体健康是有益还是有害。例如，有证据表明，长链多不饱和脂肪酸（LC-PUFA）的消费，主要是从我们的饮食中提供的鱼油，可以以有益的方式改善我们的脂肪代谢。除了用作食品外，植物油作为石化产品的替代品在广泛的工业应用中变得越来越重要，例如在替代燃料和润滑剂的生产中。尽管植物油有明显的用途和好处，但我们并不完全了解是什么控制了农作物的油产量和成分。在这些作物中，油产生于种子中。因此，为了了解和优化植物的油脂生产，我们需要了解油脂是如何在种子中产生和储存的。种子中的油以三酰甘油（TAG）的形式储存，TAG由三个脂肪酸分子与甘油连接而成。多年来，植物科学家研究了油料种子中TAG合成的生物化学，目的是了解TAG积累的代谢途径以及如何调节。然而，已经变得明显的是，TAG合成的过程仅仅是植物中整体脂质代谢的一个组成部分，使得存在用于制造油所需的生化中间体的几个竞争途径。此外，最近的研究表明，TAG合成有多种生化途径，TAG分解（catalytic）可能与合成同时发生，这使情况进一步复杂化。利用分子遗传学方法，研究人员已经确定了许多在植物脂质合成中重要的基因和代谢中间体。然而，为了了解TAG合成在油料种子中是如何被特异性调控的，我们需要评估哪些基因和代谢产物主要或特异性参与TAG代谢，哪些基因和代谢产物参与脂质代谢的其他领域。为了回答这个问题，我们计划在不同的发育阶段从模式油菜植物拟南芥中生长和收获种子，在这些阶段TAG合成已知是上调或下调的。有数百个现有的数据集显示了全球基因表达（转录组）在这些发育阶段的变化，我们计划挖掘这些数据，以找到与TAG合成相关的基因。我们还计划使用TAG合成被改变的拟南芥突变体来产生我们自己的一些转录组数据。对这些数据的分析将揭示可能在调节TAG合成中重要的其他基因。为了将种子发育过程中基因表达的变化与实际TAG合成相关联，重要的是要知道在任何一个阶段存在多少TAG，该TAG的脂肪酸组成是什么，以及其他脂质相关的生化中间体的浓度如何变化。此外，有必要监测明显不相关的生化途径如何变化，因为这些途径中的一些代谢物可能间接调节TAG生物合成。所有这些测量都可以使用代谢组学来完成，其中使用一系列分析技术来测量小分子的生化组成。选择缺乏特异性脂质代谢途径的拟南芥突变体进行代谢组学分析，以了解这些途径如何与TAG合成相关。这项研究的结果将提高我们对植物脂质代谢的理解，最终使我们能够提高植物的油脂产量和脂肪酸组成，用于饮食和工业用途。

项目成果

Enhancement of Plant Metabolite Fingerprinting by Machine Learning

• DOI: 10.1104/pp.109.150524
• 发表时间: 2010-08-01
• 期刊: PLANT PHYSIOLOGY
• 影响因子: 7.4
• 作者: Scott, Ian M.;Vermeer, Cornelia P.;Beale, Michael H.
• 通讯作者: Beale, Michael H.