丙酮酸对陈化马铃薯块茎切片线粒体抗氰呼吸的激活作用

用从陈化马铃薯切片纯化的线粒体进行实验发现：丙酮酸对总呼吸只有微弱的刺激作用，但可明显激活抗氰呼吸，并显著增强抗氰呼吸对总呼吸的贡献；丙酮酸对抗氰呼吸的激活作用可通过洗涤线粒体除去，重新加入丙酮酸又对抗氰呼吸产生激活作用；丙酮酸对抗氰呼吸的半最大激活浓度约为1．0mmol／L。上述结果表明丙酮酸对植物线粒体抗氰呼吸的激活作用可能具有普遍性。

Activation of Cyanide-resistant Respiration by Pyruvate in Mitochondria of Aged Potato Tuber Slices

Mitochondria purified from aged potato tuber slices were used to investigate whether pyruvate can activate cyanide-resistant respiration. It was found that pyruvate (5.0 mmol/L) only slightly enhanced the total respiration rates, but drastically increased the cyanide-resistant respiration rates, and resulted in pronounced increase in the contribution of cyanide-resistant respiration to total respiration. Washing the mitochondria mixture containing pyruvate eliminated the activating effects of pyruvate on cyanide-resistant respiration, and pyruvate added again caused activating effects again. The half-maximum activating effect on cyanide-resistant respiration was achieved with pyruvate of about 1.0 mmol/L. The above results give evidences indicating that the activation of cyanide-resistant respiration by pyruvate is probably a ubiquitous phenomenon in mitochondria of plants.