The chlorophyll a fluorescence induction pattern in chloroplasts upon repetitive single turnover excitations: Accumulation and function og QB-nonreducing centers

0043198 - MBÚ 2007 RIV SIGLE NL eng J - Journal Article
Vredenberg, W. - Kasalický, Vojtěch - Durchan, M. - Prášil, Ondřej
The chlorophyll a fluorescence induction pattern in chloroplasts upon repetitive single turnover excitations: Accumulation and function og QB-nonreducing centers.
[Indukce fluorescence chlorofylu a ppři sérii jednoobrátkových excitací: Akumulace a funkce Qb neredukujících center.]
Biochimica et biophysica acta. Roč. 1757, - (2006), s. 173-181. ISSN 0006-3002
R&D Projects: GA MŠMT 1P05ME824; GA ČR GA206/05/0335
Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50510513
Keywords : chlorophyll a * fluorescence quenching * photosystem 2
Subject RIV: EE - Microbiology, Virology

The increase of chlorophyll fluorescence yield in chloroplasts in a 12.5 Hz train of saturating single turnover flashes and the kinetics of fluorescence yield decay after the last flash have been analyzed. The approximate twofold increase in Fm relative to Fo, reached after 30–40 flashes, is associated with a proportional change in the slow (1–20 s) component of the multiphasic decay. This component reflects the accumulation of a sizeable fraction of QB-nonreducing centers. It is hypothesized that the generation of these centers occurs in association with proton transport across the thylakoid membrane. The data are quantitatively consistent with a model in which the fluorescence quenching of QB-nonreducing centers is reversibly released after second excitation and electron trapping on the acceptor side of Photosystem II

Práce se zabývá analýzou kinetiky nárůstu fluorescenčního výtěžku během serie saturujících záblesků a kinetikou dohasínání fluorescence. Dokazuje, že nárůst fluorescence souvisí s nárůstem amlpitudy pomalé složky dohasínání fluorescence, která odráží akumulaci části center fotosystému II, které nemohou redukovat akceptor Qb. Ukazujeme, že koncentrace těchto center souvisí s přenosem protonů přes membránu
Permanent Link: http://hdl.handle.net/11104/0136252