The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland.
Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland.
Sci Rep. 2023 Jul 10;13(1):11160. doi: 10.1038/s41598-023-38194-7.
We have analyzed the effect of salinity on photosystem II (PSII) photochemistry and plastoquinone (PQ) pool in halophytic Mesembryanthemum crystallinum plants. Under prolonged salinity conditions (7 or 10 days of 0.4 M NaCl treatment) we noted an enlarged pool of open PSII reaction centers and increased energy conservation efficiency, as envisaged by parameters of the fast and slow kinetics of chlorophyll a fluorescence. Measurements of oxygen evolution, using 2,6-dichloro-1,4-benzoquinone as an electron acceptor, showed stimulation of the PSII activity due to salinity. In salt-acclimated plants (10 days of NaCl treatment), the improved PSII performance was associated with an increase in the size of the photochemically active PQ pool and the extent of its reduction. This was accompanied by a rise in the NADP/NADPH ratio. The presented data suggest that a redistribution of PQ molecules between photochemically active and non-active fractions and a change of the redox state of the photochemically active PQ pool indicate and regulate the acclimation of the photosynthetic apparatus to salinity.
我们分析了盐度对盐生植物生石花（Mesembryanthemum crystallinum）中光合系统 II（PSII）光化学和质体醌（PQ）库的影响。在长期盐胁迫条件下（7 或 10 天 0.4 M NaCl 处理），我们注意到开放 PSII 反应中心的池增大，并且通过叶绿素 a 荧光的快速和慢速动力学参数预计能量保存效率增加。使用 2,6-二氯-1,4-苯醌作为电子受体进行的氧气释放测量表明，盐度会刺激 PSII 活性。在盐适应植物中（10 天 NaCl 处理），PSII 性能的提高与光化学活性 PQ 池的大小增加及其还原程度增加有关。这伴随着 NADP/NADPH 比的上升。所提出的数据表明，PQ 分子在光化学活性和非活性部分之间的重新分配以及光化学活性 PQ 池的氧化还原状态的变化表明并调节了光合作用器对盐度的适应。
