Institute of Basic Biological Problems, FRC PSCBR RAS, Pushchino 142290, Moscow Region, Russia.
Plant Physiol Biochem. 2021 Nov;168:501-506. doi: 10.1016/j.plaphy.2021.10.035. Epub 2021 Oct 26.
Chlamydomonas reinhardtii cells have a single large cup-shaped chloroplast that can lose lobes under high light to prevent photodamage of the photosynthetic apparatus, including photosystem II (PSII). Here, under moderate light treatment, the development of the unusual morphology of the chloroplast is shown for mutant cia3, which is deficient in carbonic anhydrase (EC 4.2.1.1) CAH3 in the thylakoid lumen, while such light intensity is harmless for wild type (WT) cells for hours. Cia3 cells had more activated PSII photoprotective mechanisms and showed a tendency to shift in the balance of the PSII damage-repair cycle, whereas PSII retained the same photosynthetic efficiency as in the WT. These findings allow speculation about the unique PSII photoprotection strategy by rearranging the chloroplast in the absence of CAH3. CAH3, in turn, is suggested to be an important participant of the C. reinhardtii photosynthetic apparatus operation, functioning in close connection with PSII.
莱茵衣藻细胞有一个单一的大型杯状叶绿体，在强光下可以失去叶瓣，以防止光合器官（包括光系统 II，PSII）受到光损伤。在这里，在适度的光照处理下，展示了突变体 cia3 叶绿体异常形态的发育，该突变体在类囊体腔中缺乏碳酸酐酶（EC 4.2.1.1）CAH3，而这种光强度对野生型（WT）细胞是无害的，可维持数小时。Cia3 细胞具有更多激活的 PSII 光保护机制，并表现出 PSII 损伤-修复循环平衡转移的趋势，而 PSII 保持与 WT 相同的光合效率。这些发现表明，在没有 CAH3 的情况下，通过重新排列叶绿体来实现独特的 PSII 光保护策略。反过来，CAH3 被认为是 C. reinhardtii 光合作用装置运行的重要参与者，与 PSII 密切相关。
