Regulation of the plant metabolic network during stress (ERA-PG 003)

了解植物对胁迫条件的反应和适应方式，对于培育主要作物新品种，使农业产量在面对不断变化的土地利用和即将到来的全球气候变化时得以保持，具有至关重要的意义。各种应激条件的一个主要后果是氧化损伤，这是由于活性氧和其他自由基的产生增加。在了解植物对氧化胁迫的反应方面已经取得了很大的进展，特别关注的是识别和表征抗氧化机制和特定的保护蛋白和代谢物。经常被忽视的是，细胞代谢也必须重新配置，以支持对还原剂和具有抗氧化活性的代谢物的增加需求，并为合成保护性代谢物提供前体。这种代谢变化可能是深远的，是导致应激耐受性的一系列分子事件的中心因素。然而，代谢变化的确切性质尚未被量化，并且对如何满足中央和次级代谢的竞争需求的精确理解尚不清楚。代谢调节是一个多方面的过程，在转录、转录后、翻译后、结构（蛋白质）和变构水平上介导。因此，理解代谢调节需要分析在每个给定的生物条件下这些水平的层次重要性。因此，在这里提出的项目中，将特别注意剖析代谢变化在网络不同部分的影响水平（酶丰度的变化与酶激活状态/效率的调节），以及氧化应激下代谢的重新配置。

An understanding of the way in which plants respond and adapt to stress conditions is of fundamental importance for the generation of new varieties of staple crop species to allow agricultural yield to be maintained in the face changing land use and impending global climate changes. A central consequence of a variety of stress conditions is oxidative damage due to increased production of reactive oxygen species and other free radicals. Much progress has been made in understanding the response of plants to oxidative stress and particular attention has focused on identifying and characterizing the antioxidant machinery and specific protective proteins and metabolites. What is often overlooked, is that cellular metabolism must also be reconfigured to support increased demands for reductant, for metabolites with antioxidant activity and to provide precursors for the synthesis of protective metabolites. This metabolic change can be profound and is a central element of the array of molecular events that lead to stress tolerance. However, the exact nature of the metabolic change has not been quantified and a precise understanding of how the competing demands on central and secondary metabolism are met is not known. Metabolic regulation is a multi-faceted process being mediated at transcriptional, post transcriptional, post translational, structural (proteinprotein) and allosteric levels. Therefore understanding metabolic regulation requires analysis of the hierarchical importance of each of these levels under each given biological condition. For this reason in the project proposed here particular attention will be paid to dissecting the level at which metabolic change is effected in different parts of the network(change in enzyme abundance versus regulation of enzyme activation state / efficiency) and the reconfiguration of metabolism in response to oxidative stress.