Superoxide production by mitochondria isolated from green bell pepper fruit
Superoxide production by mitochondria isolated from green bell pepper fruit
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DOI：
10.1111/j.1399-3054.1995.tb00993.x
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发表时间：
1995-08
影响因子：
6.4
通讯作者：
A. Purvis;R. Shewfelt;James W. Gegogeine
中科院分区：
文献类型：
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作者：
A. Purvis;R. Shewfelt;James W. Gegogeine
越来越多的证据表明，包括冷害在内的一系列环境诱导的植物失调是由胁迫过程中或缓解胁迫时产生的活性氧介导的。从冷敏型甜椒果皮组织中分离线粒体，测定其呼吸活性和在NADH、琥珀酸或苹果酸-丙酮酸处理下产生超氧化物歧化酶的能力。与NADH相比，琥珀酸对氰化物的摄取速率更高，对氰化物的敏感度更低；在2℃下贮藏的水果，其速率增加，对氰化物的敏感度和呼吸控制比(RCRs)降低。破坏线粒体膜导致NADH的耗氧量增加，琥珀酸酯的耗氧量减少，导致两种底物的RCRs约为1。NADH比琥珀酸或苹果酸-丙酮酸都能产生更多的超氧化物。超氧化物歧化酶和氰化物几乎完全抑制了超氧化物的产生。抗霉素A不能抑制NADH产生超氧化物歧化产物，但对琥珀酸有部分抑制作用，尤其是对氰化物敏感的线粒体。破坏线粒体膜可促进NADH产生超氧阴离子。2℃下贮藏的果实线粒体超氧化物歧化产物含量随NADH的增加而增加，随琥珀酸的增加而减少。结果表明，线粒体可能是低温敏感植物组织中超氧化物的主要来源。
Evidence is increasing to suggest that a wide range of environmentally induced plant disorders, including chilling injury, is mediated by reactive oxygen species produced during stress or upon relief from stress. Mitochondria were isolated from pericarp tissue of chilling-sensitive bell pepper fruit and their respiratory activity and ability to produce superoxide when supplied with NADH, succinate or malate-pyruvate were determined. Oxygen uptake rates were greater and less sensitive to cyanide with succinate than with NADH ; rates increased and sensitivity to cyanide and respiratory control ratios (RCRs) decreased in fruit stored at 2°C. Disrupting mitochondrial membranes led to increased oxygen consumption with NADH and decreased consumption with succinate, resulting in RCRs of approximately 1 with both substrates. Superoxide production was greater with NADH than with either succinate or malate-pyruvate. Superoxide dismutase and cyanide inhibited superoxide production almost completely. Antimycin A did not inhibit superoxide production with NADH, but did partially with succinate, especially in mitochondria sensitive to cyanide. Disrupting mitochondrial membranes enhanced superoxide production with NADH. Superoxide production by mitochondria isolated from fruit stored at 2°C increased with NADH and decreased with succinate. Results provide evidence that mitochondria may be a major source of superoxide in chilling-sensitive plant tissues exposed to low temperatures.