Lavaud Johann, Lepetit Bernard
Institute for Coastal Research and Environment, La Rochelle cedex, France.
Biochim Biophys Acta. 2013 Mar;1827(3):294-302. doi: 10.1016/j.bbabio.2012.11.012. Epub 2012 Nov 29.
Diatoms are a major group of microalgae whose photosynthetic productivity supports a substantial part of the aquatic primary production. In their natural environment they have to cope with strong fluctuations of the light climate which can be harmful for photosynthesis. In order to prevent the damage of their photosynthetic machinery, diatoms use fast regulatory processes among which the non-photochemical quenching of chlorophyll a fluorescence (NPQ) is one of the most important. In a previous work, we highlighted differences in the kinetics and extent of NPQ between diatom species/strains originating from different aquatic habitats. We proposed that the NPQ differences observed between strains/species could potentially participate to their ecophysiological adaptation to the light environment of their respective natural habitat. In order to better understand the molecular bases of such differences, we compared the NPQ features of four strains/species of diatoms known for their NPQ discrepancy. We could identify new spectroscopic fingerprints concomitant to NPQ and the related xanthophyll cycle. These fingerprints helped us propose a molecular explanation for the NPQ differences observed between the diatom species/strains examined. The present work further strengthens the potential role of NPQ in the ecophysiology of diatoms.
硅藻是微藻的主要类群，其光合作用生产力支撑着大部分的水生初级生产。在自然环境中，它们必须应对光照条件的剧烈波动，而这种波动可能对光合作用有害。为了防止光合机制受损，硅藻采用快速调节过程，其中叶绿素a荧光的非光化学猝灭（NPQ）是最重要的过程之一。在之前的一项研究中，我们强调了源自不同水生栖息地的硅藻物种/品系在NPQ动力学和程度上的差异。我们提出，在品系/物种之间观察到的NPQ差异可能有助于它们在生态生理上适应各自自然栖息地的光照环境。为了更好地理解这些差异的分子基础，我们比较了四种以NPQ差异而闻名的硅藻品系/物种的NPQ特征。我们能够识别与NPQ和相关叶黄素循环相伴的新光谱指纹。这些指纹帮助我们对所研究的硅藻物种/品系之间观察到的NPQ差异提出了分子解释。目前的工作进一步强化了NPQ在硅藻生态生理学中的潜在作用。
