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On the polyphasic quenching kinetics of chlorophyll a fluorescence in algae after light pulses of variable length
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SYSNO ASEP 0422526 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title On the polyphasic quenching kinetics of chlorophyll a fluorescence in algae after light pulses of variable length Author(s) Vredenberg, W. (NL)
Prášil, Ondřej (MBU-M) RID, ORCIDSource Title Photosynthesis Research. - : Springer - ISSN 0166-8595
Roč. 117, 1-3 (2013), s. 321-337Number of pages 17 s. Language eng - English Country NL - Netherlands Keywords Chlorophyll a fluorescence ; Photosystem II ; Quenching kinetics Subject RIV EE - Microbiology, Virology R&D Projects ED2.1.00/03.0110 GA MŠMT - Ministry of Education, Youth and Sports (MEYS) Institutional support MBU-M - RVO:61388971 UT WOS 000326604900022 DOI 10.1007/s11120-013-9917-z Annotation This study reports on kinetics of the fluorescence decay in a suspension of the alga Scenedesmus quadricauda after actinic illumination. These are monitored as the variable fluorescence signal in the dark following light pulses of variable intensity and duration. The decay reflects the restoration of chlorophyll fluorescence quenching of the photosystem II (PSII) antennas and shows a polyphasic pattern which suggests the involvement of different processes. The overall quenching curve after a fluorescence-saturating pulse (SP) of 250-ms duration, commonly used in pulse amplitude modulation applications as the tool for estimating the maximal fluorescence (F (m)), has been termed P-O, in which P and O have the same meaning as used in the OJIP induction curve in the light. Deconvolution of this signal shows at least three distinguishable exponential phases with reciprocal rate constants of the order of 10, 10(2), and 10(3) ms. The size of the long (> 10(3) ms) and moderate (10(2) ms) lasting components relative to the complete quenching signal after an SP increases with the duration of the actinic pulse concomitantly with an increase in the reciprocal rate constants of the fast (10 ms) and moderate quenching phases. Fluorescence responses upon single turnover flashes of 30-mu s duration (STFs) given at discrete times during the P-O quenching were used as tools for identifying the quencher involved in the P-O quenching phase preceding the STF excitation. Results are difficult to interpret in terms of a single-hit two-state trapping mechanism with distinguishable quenching properties of open and closed reaction centers only. Workplace Institute of Microbiology Contact Eliška Spurná, eliska.spurna@biomed.cas.cz, Tel.: 241 062 231 Year of Publishing 2014
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