Chou M, Chen Y M, Lin C Y
Department of Botany, National Taiwan University, Taipei, Taiwan, Republic of China.
Plant Physiol. 1989 Feb;89(2):617-21. doi: 10.1104/pp.89.2.617.
Mitochondria isolated from 2-day-old etiolated soybean (Glycine max) seedlings which had been subjected to various heat shock treatments, i.e. (A) 28 degrees C (2 h), (B) 38 degrees C (2 h), (C) 38 degrees C (2 h)-42.5 degrees C (0.5 h), and (D) 38 degrees C (2 h)-42.5 degrees C (0.5 h)-28 degrees C (4 h), were monitored for O(2) uptake using an oxygen electrode. Mitochondria isolated after all four heat shock treatments were active in O(2) consumption at 28 degrees C in response to succinate and ADP (derived P/O ratios were 1.6, 1.7, 1.3, and 1.3, respectively.) The mitochondria from all four treatments were also active in O(2) uptake at 42.5 degrees C. However, only mitochondria isolated after treatment (C) were tightly coupling at 42.5 degrees C (derived ADP/O ratio was about 1.4). Combined with our earlier findings on the subcellular localization of heat shock proteins, our present data demonstrate that association of heat shock proteins with mitochondria by treatment (C) enables them to phosphorylate at 42.5 degrees C (i.e. they become thermotolerant). Isolated mitochondria from treatment (C) and treatment (A) were compared by electron microscopy. They appeared to be very similar and no significant ultrastructural differences were noted.
从经过各种热休克处理的2日龄黄化大豆（Glycine max）幼苗中分离出线粒体，即（A）28℃（2小时），（B）38℃（2小时），（C）38℃（2小时） - 42.5℃（0.5小时），以及（D）38℃（2小时） - 42.5℃（0.5小时） - 28℃（4小时），使用氧电极监测其氧气摄取情况。在所有四种热休克处理后分离得到的线粒体在28℃下对琥珀酸和ADP有活性的氧气消耗（得出的P/O比值分别为1.6、1.7、1.3和1.3）。来自所有四种处理的线粒体在42.5℃下也有活性的氧气摄取。然而，只有在处理（C）后分离得到的线粒体在42.5℃下紧密偶联（得出的ADP/O比值约为1.4）。结合我们早期关于热休克蛋白亚细胞定位的研究结果，我们目前的数据表明，通过处理（C）使热休克蛋白与线粒体结合，能使它们在42.5℃下进行磷酸化（即它们变得耐热）。通过电子显微镜比较了处理（C）和处理（A）分离得到的线粒体。它们看起来非常相似，未观察到明显的超微结构差异。
