Effect of photosynthesis on dark mitochondrial respiration in green cells
Effect of photosynthesis on dark mitochondrial respiration in green cells
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光合作用对绿色细胞线粒体暗呼吸的影响
DOI：
10.1016/0014-5793(84)80159-3
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发表时间：
1984
期刊：
影响因子：
3.5
通讯作者：
M. S. Naik
中科院分区：
文献类型：
--
作者：
Prikhshayat Singh;M. S. Naik
绿色植物细胞在叶绿体和线粒体中都能产生ATP。因此，光合作用对暗线粒体呼吸的影响可以在不同的水平上考虑。周转的柠檬酸循环酶，这是必不可少的氨基酸合成的碳骨架的供应，似乎在光合作用过程中很大程度上不受影响。然而，在光中柠檬酸循环的回补功能的碳源并不确定。在这些反应中产生的NADH可能不会通过与ATP合成偶联的线粒体电子转移链氧化。然而，它可能被氧化的替代氰化物不敏感的途径，出口到胞质溶胶通过草酰乙酸-苹果酸二羧酸穿梭或直接用于胞质硝酸盐还原。琥珀酸盐通过细胞色素氧化酶的氧化也可以在光中类似地被抑制。由于ATP/ADP比率在黑暗中已经相当高，因此在光照下胞质ATP/ADP比率的增加是否是线粒体电子传递到O2的抑制的原因还不清楚。有效的合作之间的磷酸化和氧化磷酸化，以维持在目前的高水平的胞质能荷进行了讨论。
Green plant cells can generate ATP in both chloroplasts and mitochondria. Hence the effect of photosynthesis on dark mitochondrial respiration can be considered at a variety of levels. Turnover of ceitric acid cycle dehydrogenases, which is essential for supply of carbon skeletons for amino acid synthesis, seems to be largely unaffected during photosynthesis. The source of carbon for the anaplerotic function of the citric acid cycle in light is however, not known with certainty. NADH generated in these reactions is probably not oxidised via the mitochondrial electron transfer chain coupled to ATP synthesis. However, it may be oxidised by the alternative cyanide-insensitive pathway, exported to the cytosol via the oxaloacetate-malate dicarboxylate shuttle or directly utilised for cytosolic nitrate reduction. Oxidation of succinate via cytochrome oxidase may also be similarly inhibited in light. Whether increase in the cytosolic ATP/ADP ratio in light is responsible for the inhibition of mitochondrial electron transfer to O2is not clearly established, because the ATP/ADP ratio is reported to be already quite high in the dark. Effective collaboration between photophosphorylation and oxidative phosphorylation in order to maintain the cytosolic energy charge at a present high level is discussed.