【摘要】 由差异光谱的测定结果表明,水稻幼苗的线粒体呼吸链存在细胞色素系统的所有电子载体:黄素蛋白、细胞色素 b、细胞色素 c、细胞色素 a 和细胞色素 a₃。用氧电极测定及铁氰化物还原的结果表明,在水稻线粒体中至少存在四条电子传递途径:第一条定位于线粒体内膜内侧,对鱼藤酮、抗霉素 A 及氰化物敏感;第二条也定位于线粒体内膜内侧,但对鱼藤酮不敏感;第三条能氧化外源的 NADH,对鱼藤酮不敏感,而受抗霉素 A抑制,其 NADH 脱氢酶定位于线粒体内膜外侧;第四条途径在氧化外源 NADH 时,如有外源细胞色素 c 存在,可通过外膜上对抗霉素 A 不敏感的 NADH 脱氢酶进行电子传递。由此可以得出结论,高等植物以水稻为代表,其线粒体中的电子传递途径也是多条的。更多还原

【Abstract】 According to difference spectrum measurement,it was shown that all of the electron carriers of cytochrome systems were present in the respiratory chain of the mitochondria prepared from rice seedlings,namely FP,Cyt.b,Cyt.c,Cyt.a,Cyt.a₃. The oxygen electrode measurements and potassium ferricyanide reduction indica- ted that there were at least four routes of electron transport along the mitochondrial membranes.The first route was localized on the inner surface of the inner membrane, which was sensitive to rotenone,antimycin A and cyanide.The second route was also localized on the inner surface of the inner membrane but resistant to rotenone. The third one could oxidize exogenous NADH,but the NADH dehydrogenase associa- ted with the outer surface of the inner membrane,which was resistant to rotenone and inhibited by antimycin A.The fourth route could oxidize exogenous NADH,and in the presence of exogenous cytochorome C,it could donate electrons via dehydro- genase associated with the outer membrane which was resistant to antimycin A.The following conclusion can be drawn from the above study:multiple pathways of elec- tron transport are present in the mitochondria of higher plants.更多还原