Regulation of respiration when the oxygen availability changes
Regulation of respiration when the oxygen availability changes
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DOI：
10.1111/j.1399-3054.2009.01253.x
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发表时间：
2009-12-01
影响因子：
6.4
通讯作者：
van Dongen, Joost T.
中科院分区：
文献类型：
--
作者：
Gupta, Kapuganti J.;Zabalza, Ana;van Dongen, Joost T.
氧气是植物能量代谢的重要基质。由于植物没有复杂的机制将氧气输送到实际需要氧气的部位，因此植物细胞必须不断科普组织内氧气张力的变化。实际的内部氧浓度将取决于氧通过组织扩散的阻力以及实际的呼吸活动。本文讨论了目前的知识状态的呼吸调节的氧气供应。回顾并评论了有关植物呼吸的文献中相互矛盾的观点。此外，还包括有关动物线粒体呼吸调节的知识。除了糖酵解通量的变化，细胞色素C氧化酶（考克斯）和交替氧化酶（AOX）在呼吸的适应性反应中的作用进行了讨论的氧气供应的变化。一个假设是制定描述了替代或额外的作用AOX。这表明AOX可能在维持脑内氧稳态中起作用。由于AOX与考克斯相比对氧的亲和力相对较低，因此替代氧化酶不会干扰考克斯活性，但AOX活性会降低游离氧浓度，从而降低酶内活性氧物质（ROS）的产生。
Oxygen is a vital substrate for plant energy metabolism. Since plants do not have a sophisticated mechanism to deliver oxygen to those sites where it is actually needed, a plant cell has to continuously cope with changes of the oxygen tension within the tissue. The actual internal oxygen concentration will depend on the resistance for oxygen diffusion through the tissue, as well as on the actual respiratory activity. This paper discusses the current state of knowledge on the regulation of respiration by the oxygen availability. Contradicting opinions from the literature on plant respiration are reviewed and commented upon. Also, knowledge about the regulation of respiration in animal mitochondria is included. Apart from changes in glycolytic flux, the role of both the cytochrome-c oxidase (COX) and the alternative oxidase (AOX) in the adaptive response of respiration to changes in the oxygen availability are discussed. One hypothesis is formulated which describes an alternative or additional role for AOX. It is suggested that AOX could play a role in maintaining oxygen homeostasis within the mitochondrion. Because of the relative low affinity for oxygen of AOX as compared to COX, the alternative oxidase will not interfere with COX activity, but AOX activity will reduce the free oxygen concentration, thereby decreasing the production of reactive oxygen species (ROS) inside the mitochondrion.