Some cyanobacteria remodel their photosynthetic apparatus by a process known as Far-Red Light Photoacclimation (FaRLiP). Specific subunits of the phycobilisome (PBS), photosystem I (PSI), and photosystem II (PSII) complexes produced in visible light are replaced by paralogous subunits encoded within a conserved FaRLiP gene cluster when cells are grown in far-red light (FRL; λ = 700-800 nm). FRL-PSII complexes from the FaRLiP cyanobacterium, Synechococcus sp. PCC 7335, were purified and shown to contain Chl a, Chl d, Chl f, and pheophytin a, while FRL-PSI complexes contained only Chl a and Chl f. The spectroscopic properties of purified photosynthetic complexes from Synechococcus sp. PCC 7335 were determined individually, and energy transfer kinetics among PBS, PSII, and PSI were analyzed by time-resolved fluorescence (TRF) spectroscopy. Direct energy transfer from PSII to PSI was observed in cells (and thylakoids) grown in red light (RL), and possible routes of energy transfer in both RL- and FRL-grown cells were inferred. Three structural arrangements for RL-PSI were observed by atomic force microscopy of thylakoid membranes, but only arrays of trimeric FRL-PSI were observed in thylakoids from FRL-grown cells. Cells grown in FRL synthesized the FRL-specific complexes but also continued to synthesize some PBS and PSII complexes identical to those produced in RL. Although the light-harvesting efficiency of photosynthetic complexes produced in FRL might be lower in white light than the complexes produced in cells acclimated to white light, the FRL-complexes provide cells with the flexibility to utilize both visible and FRL to support oxygenic photosynthesis. This article is part of a Special Issue entitled Light harvesting, edited by Dr. Roberta Croce.

中文翻译：

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当蓝细菌适应远红光时，光合作用设备的广泛重塑会改变光合作用复合物之间的能量转移。

一些蓝细菌通过一种称为远红光光驯化（FaRLiP）的过程来重塑其光合作用。当细胞在远红外线（FRL）中生长时，可见光中产生的藻胆体（PBS），光系统I（PSI）和光系统II（PSII）复合物的特定亚基被保守的FaRLiP基因簇内编码的旁源亚基取代。 λ= 700-800 nm）。来自FaRLiP蓝细菌Synechococcus sp。的FRL-PSII复合物。纯化了PCC 7335，并显示其中包含Chla，Chld，Chlf和脱镁叶绿素a，而FRL-PSI复合物仅包含Chla和Chlf。Synechococcus sp。纯化的光合复合物的光谱性质。分别确定PCC 7335，并通过时间分辨荧光（TRF）光谱分析PBS，PSII和PSI之间的能量转移动力学。在红光（RL）中生长的细胞（和类囊体）中观察到了从PSII到PSI的直接能量转移，并推断了RL和FRL生长的细胞中能量转移的可能途径。通过类囊体膜的原子力显微镜观察到了RL-PSI的三种结构排列，但是在来自FRL生长的细胞的类囊体中仅观察到三聚体FRL-PSI的阵列。在FRL中生长的细胞合成了FRL特异性复合物，但仍继续合成与RL中产生的相同的一些PBS和PSII复合物。尽管在白光条件下FRL产生的光合复合物的光收集效率可能低于在适应白光的细胞中产生的复合物的收光效率，但FRL复合物为细胞提供了利用可见光和FRL来支持氧合光合作用的灵活性。