Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX13RB, UK.
Trends Plant Sci. 2010 Aug;15(8):462-70. doi: 10.1016/j.tplants.2010.05.006. Epub 2010 Jun 16.
The tricarboxylic acid (TCA) cycle is one of the iconic pathways in metabolism. The cycle is commonly thought of in terms of energy metabolism, being responsible for the oxidation of respiratory substrates to drive ATP synthesis. However, the reactions of carboxylic acid metabolism are embedded in a larger metabolic network and the conventional TCA cycle is only one way in which the component reactions can be organised. Recent evidence from labelling studies and metabolic network models suggest that the organisation of carboxylic acid metabolism in plants is highly dependent on the metabolic and physiological demands of the cell. Thus, alternative, non-cyclic flux modes occur in leaves in the light, in some developing oilseeds, and under specific physiological circumstances such as anoxia.
三羧酸循环（TCA）是代谢途径中的标志性途径之一。通常认为该循环与能量代谢有关，负责氧化呼吸底物以驱动 ATP 合成。然而，羧酸代谢的反应嵌入在更大的代谢网络中，并且传统的 TCA 循环只是可以组织组成反应的一种方式。来自标记研究和代谢网络模型的最新证据表明，植物中羧酸代谢的组织高度依赖于细胞的代谢和生理需求。因此，在光照下的叶子、某些正在发育的油籽以及缺氧等特定生理情况下，会出现替代的、非循环的通量模式。
