异柠檬酸脱氢酶在植物抗氧化胁迫中的作用

Role of Isocitrate Dehydrogenase on Oxidative Stress in Plants

异柠檬酸脱氢酶(ICDH)是连接C-N代谢酶的关键,它催化三羧酸循环(TCA)中的异柠檬酸氧化脱羧形成α-酮戊二酸的可逆反应。ICDH的另一个重要功能是产生细胞质中的NADPH,NADPH在细胞中无处不在,介导许多氧化还原反应,并影响到几乎所有的代谢途径,涉及植物体内的活性氧(ROS)的生产和消耗,因此是传递胁迫信号的中转站。综述异柠檬酸脱氢酶在植物抗氧化胁迫中的作用,便于更好地理解ICDH在氧化胁迫中的信号传递和化学反应中所起的作用,为抗逆分子育种服务。

NAD-dependent isocitrate dehydrogenase （ ICDH ） is believed to be a key regulatory step of the TCA cycle due to its low extractable activity and its regulation by key metabolites such as NADPH. ICDH is hypothesized to have a key function in the biosynthesis of amino acids and in the export of amino acids. In addition, NADP-ICDH may have an important role in the supply of NADPH to the cytosol. Thus the function of NADP-ICDH might be associated with a supply of NADPH to the glutathione reductase/glutathione peroxidase antioxidative system in the eytosol for detoxification of H202. This paper reviews the oxidative stress role of ICDH in plants, for a better understanding ICDH in the oxidative signal transduetion in stress resistance and chemical reactions.