Laboratoire de Biologie Végétale IV, Université Pierre et Marie Curie, Paris, France.
Plant Physiol. 1976 Aug;58(2):147-51. doi: 10.1104/pp.58.2.147.
Aging of slices of potato tuber (Solanum tuberosum L.) in an aerated liquid medium induces a number of changes in mitochondrial activities. A nonphosphorylative, cyanide-insensitive electron transport pathway (alternate pathway) is brought into operation. The rate of oxidation of exogenous NADH increases markedly and the efficiency of phosphorylation with this substrate remains the same as it is in mitochondria isolated from fresh tissue slices. On the contrary, the rates of oxidation of succinate and malate do not increase while lower phosphorylative efficiencies indicate that a fraction of their electrons reaches oxygen through the alternate pathway. Chloramphenicol, a specific inhibitor of the mitochondrial protein-synthesizing system, has no effect whatsoever on these events. However, cycloheximide, which acts on the corresponding cytoplasmic system, prevents both the development of the alternate pathway and the rise in the rate of oxidation of exogenous NADH. These effects are interpreted as showing a specific control of the cytoplasmic protein-synthesizing system on the changes in mitochondrial oxidations during aging.
在充气的液体介质中，马铃薯薯块切片的老化会引起线粒体活性的许多变化。一种非磷酸化的、氰化物不敏感的电子传递途径（替代途径）被启动。外源 NADH 的氧化速率显著增加，并且与从新鲜组织切片中分离的线粒体相比，该底物的磷酸化效率保持不变。相反，琥珀酸和苹果酸的氧化速率没有增加，而较低的磷酸化效率表明它们的一部分电子通过替代途径到达氧气。氯霉素，一种线粒体蛋白合成系统的特异性抑制剂，对这些事件没有任何影响。然而，环己亚胺，一种作用于相应的细胞质系统的药物，既阻止了替代途径的发展，也阻止了外源 NADH 氧化速率的上升。这些效应表明，细胞质蛋白合成系统对衰老过程中线粒体氧化变化的特异性控制。
