The analysis of PS II photochemical activity using single and multi-turnover excitations

0387345 - MBÚ 2013 RIV CH eng J - Journal Article
Vredenberg, W. - Durchan, M. - Prášil, Ondřej
The analysis of PS II photochemical activity using single and multi-turnover excitations.
Journal of Photochemistry and Photobiology. B - Biology Section. Roč. 107, FEB 6 2012 (2012), s. 45-54. ISSN 1011-1344. E-ISSN 1873-2682
R&D Projects: GA ČR GA206/08/1683; GA MŠMT(CZ) ED2.1.00/03.0110; GA MŠMT 7E09099
Institutional research plan: CEZ:AV0Z50200510
Keywords : Photochemical activity * Photosystem II * Chlorophyll a fluorescence
Subject RIV: EE - Microbiology, Virology
Impact factor: 3.110, year: 2012

Paper describes chlorophyll a fluorescence measurements in algal cells, and intact plant leaves and isolated chloroplasts. It focuses on amplitude and 10 mu-resolved kinetics of variable fluorescence responses upon excitation with fluorescence-saturating pulses (SP) and with 25 mu s saturating single turnover flashes (STF) which are exposed before, during and after a 100 s actinic illumination (AL) of low and high intensity. In addition to the amply documented suppression of the maximal variable fluorescence from F-m to F'(m), the relative proportion of the distinguished O-J-, J-I- and I-P-phases of an SP-induced response is shown to be distinctly different in dark- and light-adapted leaves. The O-J-phase in the 0.01-1 ms time range is much less sensitive to light adaptation than the other phases in the 1-200 ms range. In algae and chloroplasts, the amplitude F-m(ST) of the STF-induced response is hardly affected by a shift from the dark- to the light-activated steady state. The results support the hypothesis that the maximal variable fluorescence F, induced by a multiple-turnover, fluorescence-saturating pulse (SP), is associated with the release of photochemical and photoelectrochemical quenching
Permanent Link: http://hdl.handle.net/11104/0219821