【摘要】 用马铃薯软腐病菌处理烟草后,以化学法测定了叶片中O2-·含量,发现在接种后1￣14h内只出现一次O2-·爆发,不同于以往植物悬浮细胞研究中出现的两次爆发结果。接种软腐病菌后2h和6h烟草叶片O2-·的电子自旋共振波谱图(electronspinresonance,ESR)显示了同样的一次O2-·爆发结果。接种后烟草叶片的线粒体和叶绿体O2-·爆发与叶片的同步,显示此两种细胞器参与烟草叶片在软腐病菌作用下的O2-·发生。无光照叶绿体O2-·的ESR谱线不出现,表明叶绿体O2-·可能来源于光合电子传递链。马铃薯软腐病菌作用下烟草叶片的O2-·爆发是多位点的。更多还原

【Abstract】 O2ˉ· production based on chemical methodby Ecc-treated intact tobacco leaves was observed.It showed a long-lasting one-phase course begin-ning 1 h and ending 14 h after Erwinia carotovorasubsp. carotovora (Ecc) was inoculated. In Ecc-treated leaves, O2ˉ· production rate of 3 h is 2 timesof 1 h, and of 10 h it remains 1.7 times. It decreasesrapidly between 10 h and 14 h, at 14 h it falls to thelevel before inoculation. This is a completely differ-ent course from the widely accepted two-phasecourse obtained from suspension-cultured cells (Fig.1).Electron spin resonance (ESR) spectrum of O2·ˉ pro-duced by intact tobacco leaves after Ecc inocula-tion 2 h and 6 h was also observed, the amplitudeof 6 h is larger than of 2 h in Ecc-treated group. Inthe control group, there is no difference betweenthe amplitude of 2 h and 6 h. This indicated that O2ˉ·amount of Ecc-treated group is higher than of thecontrol group, which is the same result as obtainedthrough chemical method (Fig.2a). The ESR spec-trum of O2ˉ· produced by chloroplasts and mitochon-dria from tobacco leaves after 2 h and 6 h after Ecc inoculation were observed. In chloroplastexperiment, the amplitude of 6 h was larger than of2 h in Ecc-treated group while it was the same inthe control group (Fig.2b). ESR spectrum of O2ˉ· pro-duced by mitochondria was proved to be a same re-sult after a careful comparison, in spite of a greaterdifference between 2 h and 6 h in control groupthan chloroplast experiment (Fig.2c). The fact thatspectra of these two organelles were both synchro-nous with that of intact leaves implied that these twoorganelles possibly participated in cellular O2·ˉ burst.Chloroplasts in the dark showed no ESR spectrum2 h and 6 h after Ecc inoculation in Ecc-treated groupas well as in the control group (Fig.2a), indicatingthat O2ˉ· in the chloroplast probably originated fromthe photosynthetic electron transport process.更多还原