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

0390058 - MBÚ 2013 RIV NL eng J - Journal Article
Kaňa, Radek - Kotabová, Eva - Komárek, Ondřej - Šedivá, Barbora - Papageorgiou, G. C. - Govindjee, G. - Prášil, Ondřej
The slow S to M fluorescence rise in cyanobacteria is due to a state 2 to state 1 transition.
Biochimica Et Biophysica Acta-Bioenergetics. Roč. 1817, č. 8 (2012), s. 1237-1247. ISSN 0005-2728. E-ISSN 1879-2650
R&D Projects: GA ČR GP206/09/P094; GA MŠMT(CZ) ED2.1.00/03.0110; GA ČR GBP501/12/G055
Institutional support: RVO:61388971
Keywords : Cyanobacterium * Fluorescence induction * RpaC(-) mutant
Subject RIV: EE - Microbiology, Virology
Impact factor: 4.624, year: 2012

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 "S to M rise" 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(-) 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 marinas 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
Permanent Link: http://hdl.handle.net/11104/0219029