烟草赤星病菌代谢产物诱导的烟草BY-2细胞ROS爆发和ATP损耗

ROS Burst and ATP Depletion in Tobacco BY-2 Cells Induced by Metabolic Products of Alternaria alternata

【目的】探讨赤星病菌代谢产物(metabolic products of Alternaria alternata,MP)对烟草BY-2细胞活性氧(reactive oxygen species,ROS)产生和ATP含量的影响以及产生这种影响的原因。【方法】用10%MP处理烟草BY-2细胞,用氧电极检测不同MP处理时间后,烟草BY-2细胞呼吸速率和呼吸途径的变化,同时分析BY-2细胞内H2O2产生和ATP含量等的变化。【结果】MP处理导致了烟草BY-2细胞H2O2爆发和ATP含量下降,此外,MP处理也导致了烟草BY-2细胞总呼吸速率、细胞色素途径(cytochrome pathway)和交替氧化酶途径(AOX)的下降,并且造成线粒体通透转换孔道(permeability transition pore,PTP)开放和细胞色素c释放。【结论】MP对BY-2细胞呼吸速率和细胞色素途径的抑制不可避免地导致胞内ATP含量下降,此外MP诱导的烟草BY-2细胞氧化磷酸化的解偶联作用是MP导致胞内ATP含量下降的另一重要原因。而MP对AOX途径的抑制则是诱导胞内ROS爆发的重要原因。

【Objective】The objective of this study is to explore the effect of the Alternaria alternata metabolic products（MP） on changes of reactive oxygen species（ROS） production and ATP content in the tobacco BY-2 cells.【Method】10% MP was used to treat tobacco BY-2 cells,and Oxytherm oxygen electrode was used to study the effects of MP on the reparation rate and reparation pathway in the tobacco BY-2 cells.The changes of ROS production and ATP content in tobacco BY-2 cells was also studied.【Result】Treatment with the MP led to remarkable overproduction of ROS,rapid depletion of ATP,significant declines in respiration,in cytochrome pathway and in alternative oxidase pathway（AOX）.The treatment with MP also resulted in uncoupling of oxidative phosphorylation,opening of the permeability transition pore（PTP） and release of cytochrome c from mitochondria to cytoplasm in tobacco BY-2 cells.【Conclusion】The inhibition of respiration and cytochrome pathway inevitably result in ATP depletion in tobacco BY-2 cells.The uncoupling of oxidative phosphorylation induced by MP is another contributor to the ATP depletion.The inhibition of AOX pathway by the MP treatment is one of the main reasons which lead to the ROS burst in tobacco BY-2 cells.