Control of the maximal chlorophyll fluorescence yield by the Q(B) binding site

0489336 - MBÚ 2019 RIV NL eng J - Journal Article
Prášil, Ondřej - Kolber, Z. S. - Falkowski, P. G.
Control of the maximal chlorophyll fluorescence yield by the Q(B) binding site.
Photosynthetica. Roč. 56, č. 1 (2018), s. 150-162. ISSN 0300-3604. E-ISSN 1573-9058
R&D Projects: GA MŠMT(CZ) LO1416
Institutional support: RVO:61388971
Keywords : conformational change * electron transport * photosystem II
OECD category: Microbiology
Impact factor: 2.365, year: 2018

Differences in maximal yields of chlorophyll variable fluorescence (F-m) induced by single turnover (ST) and multiple turnover (MT) excitation are as great as 40%. Using mutants of Chlamydomonas reinhardtii we investigated potential mechanisms controlling F-m above and beyond the Q(A) redox level. F-m was low when the Q(B) binding site was occupied by PQ and high when the Q(B) binding site was empty or occupied by a PSII herbicide. Furthermore, in mutants with impaired rates of plastoquinol reoxidation, F-m was reached rapidly during MT excitation. In PSII particles with no mobile PQ pool, F-m was virtually identical to that obtained in the presence of PSII herbicides. We have developed a model to account for the variations in maximal fluorescence yields based on the occupancy of the Q(B) binding site. The model predicts that the variations in maximal fluorescence yields are caused by the capacity of secondary electron acceptors to reoxidize Q(A)(-).
Permanent Link: http://hdl.handle.net/11104/0283783