The slow S to M fluorescence rise in cyanobacteria is due to a state 2 to state 1 transition

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• 作者：Radek Ka艌a^a ; ^b ; ^kana@alga.cz ; Eva Kotabov&aacute ; ^a ; ^b ; Ond艡ej Kom&aacute ; rek^a ; Barbora &Scaron ; ediv&aacute ; ^a ; George C. Papageorgiou^c ; Govindjee^d ; ^e ; Ond艡ej Pr&aacute ; &scaron ; il^a ; ^b
• 关键词：apc ; allophycocyanin ; Chl a ; chlorophyll a ; FI ; fluorescence induction ; Fm (Fm&rsquo ; ) ; maximal chlorophyll a fluorescence for dark (light) adapted sample ; 鈭咶m&rsquo ; (rel) ; relative changes in maximal fluorescence in light (in%) ; PC ; phycocyanin ; DCMU
• 刊名：Biochimica et Biophysica Acta (BBA)/Bioenergetics
• 出版年：2012
• 期刊代码：13_00052728
• 类别：bio
• 出版时间：August, 2012
• 卷：1817
• 期：8
• 页码：1237-1247
• 文件大小：1733 K

摘要

In dark-adapted plants and algae, chlorophyll a fluorescence induction peaks within 1 s after irradiation due to well documented photochemical and non-photochemical processes. Here we show that the much slower fluorescence rise in cyanobacteria (the so-called 鈥淪 to M rise鈥?in tens of seconds) is due to state 2 to state 1 transition. This has been demonstrated in particular for Synechocystis PCC6803, using its RpaC^{鈭?/sup> mutant (locked in state 1) and its wild-type cells kept in hyperosmotic suspension (locked in state 2). In both cases, the inhibition of state changes correlates with the disappearance of the S to M fluorescence rise, confirming its assignment to the state 2 to state 1 transition. The general physiological relevance of the SM rise is supported by its occurrence in several cyanobacterial strains: Synechococcus (PCC 7942, WH 5701) and diazotrophic single cell cyanobacterium (Cyanothece sp. ATCC 51142). We also show here that the SM fluorescence rise, and also the state transition changes are less prominent in filamentous diazotrophic cyanobacterium Nostoc sp. (PCC 7120) and absent in phycobilisome-less cyanobacterium Prochlorococcus marinus PCC 9511. Surprisingly, it is also absent in the phycobiliprotein rod containing Acaryochloris marina (MBIC 11017). All these results show that the S to M fluorescence rise reflects state 2 to state 1 transition in cyanobacteria with phycobilisomes formed by rods and core parts. We show that the pronounced SM fluorescence rise may reflect a protective mechanism for excess energy dissipation in those cyanobacteria (e.g. in Synechococcus PCC 7942) that are less efficient in other protective mechanisms, such as blue light induced non-photochemical quenching. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.}