改变电子流量对烟草愈伤组织抗氰呼吸的影响

Effects of Changes in Electron Flow on the Cyanide- resistant Respiration in Tobacco Callus

改变电子流量对电子流在继代培养的烟草愈伤组织细胞色素途径和交替途径之间的实际分配情况的研究表明 ,用 DNP增大呼吸电子流 ,交替途径和细胞色素途径实际运行量都加强 .前者的增加量稍大于后者 ,反映到对总呼吸的贡献上 ,也得到同样的结论 ,这可能是由于细胞色素途径电子流量达到饱和所致 .而用底物代谢抑制剂来降低呼吸电子流时 ,细胞色素途径实际运行对总呼吸的贡献随呼吸电子流的不断下降而增加 ;相反 ,抗氰呼吸运行对总呼吸的贡献则逐渐降低 .推测这可能是愈伤组织通过协同调节两条电子传递途径来维持细胞正常生理活动所必需的能量( ATP) .

The practical assignment of electron flow between the alternative pathway and the cytochrome pathway was examined when electron flow was altered in subcultured tobacco callus. The result indicated that when 2,4-dinitrophenol (DNP) was used to enhance electron flow, both the practical operations of the alternative pathway and the cytochrome pathway were increased, with the former increased more considenably. But the contribution of the cytochrome pathway to total respiration increased gradually and that of the alternative pathway to total respiration declined greatly when metabolic inhibitors were used to decrease the electron flow. It was deduced that the enhancement of the alternative pathway, when electron flow was increased, might be due to the saturation of electron flow to the cytochrome pathway, while the reduction of the alternative pathway along with the decrease in election flow might result from the coordinate regulation of cytochrome and alternative pathways.