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Temporary suppression of the flash‐induced electrical potential across the thylakoid membrane upon energization
Author(s) -
Voorthuysen Tijmen,
Dassen Hans H. A.,
Snel Jan F. H.,
Vredenberg Wim J.
Publication year - 1995
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1995.tb00991.x
Subject(s) - thylakoid , membrane potential , photosystem ii , quenching (fluorescence) , biophysics , photochemistry , chemistry , photosynthetic reaction centre , analytical chemistry (journal) , fluorescence , chloroplast , photosynthesis , biology , physics , optics , electron transfer , biochemistry , chromatography , gene
Energization of the chloroplast thylakoid membrane causes a temporary decrease in the amplitude of the flash‐induced transmembrane electrical potential as monitored by the micro‐electrode technique and by the electrochromic absorbance band shift at 518 nm in chloroplasts of Peperomia metallica. This energization‐dependent decrease of the flash‐induced potential has a relaxation time of recovery in the dark of about 23±4 s. The phenomenon can neither be explained by a decrease of the intrinsic efficiency of photosystem I and II (PSI and PSII) nor by a partial closure of reaction centers of PSI and PSII. This leads us to propose that the energization‐dependent decrease of the amplitude of the flash‐induced electrical potential is caused by either the formation of a fraction of PSI and/or PSII reaction centers with fast charge recombination or by an increase of the membrane capacitance. The dark recovery after energization of the amplitude of the transmembrane electrical potential and that of non‐photochemical fluorescence quenching were found to be comparable, which suggests a common cause for both phenomena.