Meneghesso Andrea, Simionato Diana, Gerotto Caterina, La Rocca Nicoletta, Finazzi Giovanni, Morosinotto Tomas
Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, 35121, Padua, Italy.
Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Université Grenoble Alpes, Institut National Recherche Agronomique (INRA), Institut de Recherche en Sciences et Technologies pour le Vivant (iRTSV), CEA Grenoble, 38054, Grenoble Cedex 9, France.
Photosynth Res. 2016 Sep;129(3):291-305. doi: 10.1007/s11120-016-0297-z. Epub 2016 Jul 22.
Nannochloropsis is an eukaryotic alga of the phylum Heterokonta, originating from a secondary endosymbiotic event. In this work, we investigated how the photosynthetic apparatus responds to growth in different light regimes in Nannochloropsis gaditana. We found that intense illumination induces the decrease of both photosystem I and II contents and their respective antenna sizes. Cells grown in high light showed a larger capacity for electron transport, with enhanced cyclic electron transport around photosystem I, contributing to photoprotection from excess illumination. Even when exposed to excess light intensities for several days, N. gaditana cells did not activate constitutive responses such as nonphotochemical quenching and the xanthophyll cycle. These photoprotection mechanisms in N. gaditana thus play a role in acclimation to fast changes in illumination within a time range of minutes, while regulation of the electron flow capacity represents a long-term response to prolonged exposure to excess light.
微拟球藻是不等鞭毛门的一种真核藻类，起源于次生内共生事件。在这项研究中，我们研究了微拟球藻（Nannochloropsis gaditana）的光合机构如何响应不同光照条件下的生长。我们发现，强光照射会导致光系统I和II的含量及其各自天线大小的降低。在高光下生长的细胞表现出更大的电子传递能力，光系统I周围的循环电子传递增强，有助于对过量光照进行光保护。即使暴露在过量光强下数天，微拟球藻细胞也不会激活诸如非光化学猝灭和叶黄素循环等组成性反应。因此，微拟球藻中的这些光保护机制在几分钟的时间范围内适应光照的快速变化中发挥作用，而电子流动能力的调节则代表了对长期暴露于过量光照的长期反应。
