Department of Biology, School of Pure Sciences, College of Engineering Science and Technology, Fiji National University , Natabua, Fiji Islands.
Plant Signal Behav. 2020 Dec 1;15(12):1824721. doi: 10.1080/15592324.2020.1824721. Epub 2020 Sep 24.
The oxygen-evolving complex is integrated into photosystem (PSII). An essential part of oxygenic photosynthetic apparatus, embedded in the thylakoid membrane of chloroplasts. The OEC is a super catalyst to split water into molecular oxygen in the presence of light. The OEC consist of four Mn atoms, one Ca atom and five oxygen atoms (CaMnO) and this cluster is maintained by its surrounding proteins ., PsbQ, PsbP, PsbO, PsbR. The function of this super catalyst with a high turnover frequency of 500 s in standard condition. Chlorophyll a fluorescence (OJIP transients) are used to understand structural and functional cohesion of photosynthetic apparatus. A further K-peak in OJIP curve reflects damage at the OEC donor site in response to salinity, drought, and high temperature. The decline in performance indices (PI, SFI) also revealed structural damage of photosynthetic apparatus that leads to disruption of electron transport rate under abiotic conditions. This review discusses the structural and function cohesion of the OEC in plant against variable abiotic conditions.
放氧复合体集成在光合作用系统 II（PSII）中。它是产氧光合作用装置的重要组成部分，嵌入在叶绿体的类囊体膜中。在光照条件下，OEC 是一种将水分解为分子氧的超催化剂。OEC 由四个锰原子、一个钙原子和五个氧原子（CaMnO）组成，这个簇由其周围的蛋白质 PsbQ、PsbP、PsbO 和 PsbR 维持。在标准条件下，这个超催化剂的周转率高达 500 秒，功能强大。叶绿素 a 荧光（OJIP 瞬变）用于理解光合作用装置的结构和功能的凝聚性。OJIP 曲线中的进一步 K 峰反映了在盐度、干旱和高温条件下，OEC 供体部位的损伤。性能指数（PI、SFI）的下降也揭示了光合作用装置的结构损伤，导致在非生物条件下电子传递速率中断。本综述讨论了在可变的非生物条件下，植物中 OEC 的结构和功能的凝聚性。
