...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Plant and Cell Physiology >Distinct Roles of the Cytochrome Pathway and Alternative Oxidase in Leaf Photosynthesis
【24h】

Distinct Roles of the Cytochrome Pathway and Alternative Oxidase in Leaf Photosynthesis

机译：细胞色素途径和替代氧化酶在叶片光合作用中的不同作用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In illuminated leaves, mitochondria are thought to play roles in optimizing photosynthesis. However, the roles of the cytochrome pathway (CP) and alternative oxidase (AOX) in photosynthesis, in particular in the redox state of the photosynthetic electron transport chain, are not separately characterized. We examined the effects of specific inhibition of two respiratory pathways, CP and AOX, on photosynthetic oxygen evolution and the redox state of the photosynthetic electron transport chain in broad bean (Vicia faba L.) leaves under various light intensities. Under saturating photosynthetic photon flux density (PPFD; 700 µmol photon m–2 s–1), inhibition of either pathway caused a decrease in the steady-state levels of the photosynthetic O2 evolution rate and the PSII operating efficiency, ΦII. Because these inhibitors, at the concentrations applied to the leaves, had little effect on photosynthesis in the intact chloroplasts, two respiratory pathways are essential for maintenance of high photosynthetic rates at saturating PPFD. CP or AOX inhibition affected to Chl fluorescence parameters (e.g. photochemical quenching and non-photochemical quenching) differently, suggesting that CP and AOX contribute to photosynthesis in different ways. At low PPFD (100 µmol photon m–2 s–1), only the inhibition of AOX, not CP, lowered the photosynthetic rate and ΦII. AOX inhibition also decreased the ΦII/ΦI ratio even at low PPFD levels. These data suggest that AOX inhibition caused the over-reduction of the photosynthetic electron transport chain and induced the cyclic electron flow around PSI (CEF-PSI) even at the low PPFD. Based on these results, we discuss possible roles for CP and AOX in the light.
机译：在光照的叶子中，线粒体被认为在优化光合作用中发挥了作用。但是，细胞色素途径（CP）和替代氧化酶（AOX）在光合作用中的作用，特别是在光合作用电子传输链的氧化还原状态中，没有被分别表征。我们研究了在两种光强度下，蚕豆（Vicia faba L.）叶片上两种呼吸途径CP和AOX的特异性抑制作用对光合氧进化和光合电子传递链的氧化还原状态的影响。在饱和光合作用光子通量密度（PPFD； 700 µmol光子m –2 s –1 ）下，任一途径的抑制都会导致光合作用的稳态水平降低O 2 的演化速率和PSII的运行效率Φ II 。因为这些抑制剂在施加到叶片上的浓度下对完整叶绿体中的光合作用几乎没有影响，所以两个呼吸途径对于维持饱和PPFD时的高光合速率至关重要。 CP或AOX抑制对Chl荧光参数（例如光化学猝灭和非光化学猝灭）的影响不同，这表明CP和AOX以不同的方式促进光合作用。在低PPFD（100 µmol光子m –2 s –1 ）下，仅抑制AOX而非CP会降低光合速率和Φ II 。即使在低PPFD水平下，AOX抑制作用也会降低Φ II /Φ I 比率。这些数据表明，即使在低PPFD下，AOX抑制也会引起光合电子传递链的过度还原，并引起PSI（CEF-PSI）周围的循环电子流。基于这些结果，我们将讨论CP和AOX的可能作用。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号