Biological Faculty, Moscow State University, Moscow, 119234, Russia.
Biological Faculty, Shenzhen MSU-BIT University, Shenzhen, 518172, China.
Cell Biochem Biophys. 2024 Jun;82(2):729-745. doi: 10.1007/s12013-024-01224-w. Epub 2024 Feb 10.
The model of thylakoid membrane system (T-M model) (Belyaeva et al. Photosynth Res 2019, 140:1-19) has been improved in order to analyze the induction data for dark-adapted samples of algal (Scenedesmus obliques) and cyanobacterial (Synechocystis sp. PCC 6803) cells. The fluorescence induction (FI) curves of Scenedesmus were measured at light exposures of 5 min, while FI and P700 redox transformations of Synechocystis were recorded in parallel for 100 s intervals. Kinetic data comprising the OJIP-SMT fluorescence induction and OABCDEF P700 absorbance changes were used to study the processes underlying state transitions qT and qT associated with the increase/decrease in Chl fluorescence emission. A formula with the Hill kinetics (Ebenhöh et al. Philos Trans R Soc B 2014, 369:20130223) was introduced into the T-M model, with a new variable to imitate the flexible size of antenna Ant(t) associated with PSII. Simulations revealed that the light-harvesting capacity of PSII increases with a corresponding decrease for that of PSI upon the qT transition induced by plastoquinone (PQ) pool oxidation. The complete T-M model fittings were attained on Scenedesmus or Synechocystis fast waves OJIPS of FI, while SMT wave of FI was reproduced at intervals shorter than 5 min. Also the fast P700 redox transitions (OABC) for Synechocystis were fitted exactly. Reasonable sets of algal and cyanobacterial electron/proton transfer (ET/PT) parameters were found. In the case of Scenedesmus, ET/PT traits remained the same irrespective of modeling with or without qT transitions. Simulations indicated a high extent (20%) of the PQ pool reduction under dark conditions in Synechocystis compared to 2% in Scenedesmus.
为了分析藻类（斜生栅藻）和蓝细菌（集胞藻 PCC 6803）暗适应样品的诱导数据，对类囊体膜系统模型（T-M 模型）（Belyaeva 等人，Photosynth Res 2019, 140:1-19）进行了改进。在 5 分钟的光暴露下测量了斜生栅藻的荧光诱导（FI）曲线，而同时记录了集胞藻的 FI 和 P700 氧化还原转化，记录时间间隔为 100 秒。动力学数据包括 OJIP-SMT 荧光诱导和 OABCDEF P700 吸光度变化，用于研究与 Chl 荧光发射增加/减少相关的 qT 和 qT 状态转变过程。引入了具有 Hill 动力学（Ebenhöh 等人，Philos Trans R Soc B 2014, 369:20130223）的公式到 T-M 模型中，引入了一个新变量来模拟与 PSII 相关的天线 Ant(t)的灵活大小。模拟结果表明，在质体醌（PQ）池氧化诱导的 qT 转变过程中，PSII 的光捕获能力增加，而 PSI 的光捕获能力相应降低。在 Scenedesmus 或 Synechocystis 的 FI 快速 OJIPS 上实现了完整的 T-M 模型拟合，而在 5 分钟以内的时间间隔内重现了 FI 的 SMT 波。也准确地拟合了 Synechocystis 的快速 P700 氧化还原转化（OABC）。找到了合理的藻类和蓝细菌电子/质子转移（ET/PT）参数集。在 Scenedesmus 的情况下，无论是否进行 qT 转变建模，ET/PT 特征都保持不变。模拟表明，与 Scenedesmus 相比，Synechocystis 在黑暗条件下 PQ 池还原的程度较高（20%），而 Scenedesmus 为 2%。
