CEA Saclay, iBiTec-S, CNRS URA 2096, Service de Bioénergétique Biologie Structurales et Mécanismes, F-91191 Gif-sur-Yvette Cedex, France.
J Exp Bot. 2010 Aug;61(13):3577-87. doi: 10.1093/jxb/erq171. Epub 2010 Jul 1.
Hydrogen peroxide (H(2)O(2)) is recognized as an important signalling molecule. There are two important aspects to this function: H(2)O(2) production and its diffusion to its sites of action. The production of H(2)O(2) by photosynthetic electron transport and its ability to diffuse through the chloroplast envelope membranes has been investigated using spin trapping electron paramagnetic resonance spectroscopy and H(2)O(2)-sensitive fluorescence dyes. It was found that, even at low light intensity, a portion of H(2)O(2) produced inside the chloroplasts can leave the chloroplasts thus escaping the effective antioxidant systems located inside the chloroplast. The production of H(2)O(2) by chloroplasts and the appearance of H(2)O(2) outside chloroplasts increased with increasing light intensity and time of illumination. The amount of H(2)O(2) that can be detected outside the chloroplasts has been shown to be up to 5% of the total H(2)O(2) produced inside the chloroplasts at high light intensities. The fact that H(2)O(2) produced by chloroplasts can be detected outside these organelles is an important finding in terms of understanding how chloroplastic H(2)O(2) can serve as a signal molecule.
过氧化氢 (H(2)O(2)) 被认为是一种重要的信号分子。其功能有两个重要方面：H(2)O(2) 的产生及其向作用部位的扩散。通过自旋捕获电子顺磁共振波谱和 H(2)O(2) 敏感荧光染料研究了光合作用电子传递产生 H(2)O(2)及其扩散穿过叶绿体包膜的能力。结果发现，即使在低光强下，一部分在叶绿体内部产生的 H(2)O(2)也可以离开叶绿体，从而逃避位于叶绿体内部的有效抗氧化系统。随着光强和光照时间的增加，叶绿体产生 H(2)O(2)和 H(2)O(2)出现在叶绿体外部的现象也增加了。在高光强下，检测到的叶绿体外部的 H(2)O(2)量可达叶绿体内部产生的 H(2)O(2)总量的 5%。事实上，在这些细胞器之外可以检测到由叶绿体产生的 H(2)O(2)，这对于理解叶绿体 H(2)O(2)如何作为信号分子具有重要意义。
