Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, 1081 HV Amsterdam, The Netherlands.
Laboratory of Biophysics, Wageningen University, 6700 ET Wageningen, The Netherlands.
Plant Physiol. 2019 Mar;179(3):1132-1143. doi: 10.1104/pp.18.01499. Epub 2019 Jan 16.
In contrast to single cellular species, detailed information is lacking on the processes of photosynthetic acclimation for colonial algae, although these algae are important for biofuel production, ecosystem biodiversity, and wastewater treatment. To investigate differences between single cellular and colonial species, we studied the regulation of photosynthesis and photoprotection during photoacclimation for the colonial green alga and made a comparison with the properties of the single cellular species We show that shares some high-light (HL) photoacclimation strategies with and other frequently studied green algae: decreased chlorophyll content, increased free carotenoid content, and increased nonphotochemical quenching (NPQ). Additionally, has unique HL photoacclimation strategies, related to its colonial form: strong internal shading by an increase of the colony size and the accumulation of extracellular echinenone (a ketocarotenoid). HL colonies are larger and more spatially heterogenous than low-light colonies. Compared with surface cells, cells deeper inside the colony have increased pigmentation and larger photosystem II antenna size. The core of the largest of the HL colonies does not contain living cells. In contrast with , but similar to other biofilm-forming algae, NPQ capacity is substantial in low light. In HL, NPQ amplitude increases, but kinetics are unchanged. We discuss possible causes of the different acclimation responses of and Knowledge of the specific photoacclimation processes for this colonial green alga further extends the view of the diversity of photoacclimation strategies in photosynthetic organisms.
与单细胞物种相比，关于聚生藻类的光合作用适应过程的详细信息还很缺乏，尽管这些藻类对于生物燃料生产、生态系统生物多样性和废水处理很重要。为了研究单细胞和聚生藻类之间的差异，我们研究了聚生绿藻在光驯化过程中光合作用和光保护的调节，并与单细胞物种的特性进行了比较。我们表明，与其他经常研究的绿藻一样，聚生的 具有一些高光（HL）光驯化策略：叶绿素含量降低，游离类胡萝卜素含量增加，非光化学猝灭（NPQ）增加。此外， 具有独特的 HL 光驯化策略，与它的聚生形式有关：通过增加菌落大小和积累细胞外echinenone（一种酮类胡萝卜素）来实现强烈的内部遮光。HL 菌落比低光菌落更大且空间异质性更强。与表面细胞相比，菌落内部更深的细胞具有更高的色素沉着和更大的光系统 II 天线大小。最大的 HL 菌落的核心不包含活细胞。与 不同，但与其他形成生物膜的藻类相似，在低光下 NPQ 容量很大。在 HL 中，NPQ 幅度增加，但动力学不变。我们讨论了 和 适应反应不同的可能原因。对这种聚生绿藻特定光适应过程的了解进一步扩展了对光合生物光适应策略多样性的认识。
