PMID: 7323Jul 9, 1976

Primary reactions of photosystem II at low pH. 2. Light-induced changes of absorbance and electron spin resonance in spinach chloroplasts

Biochimica Et Biophysica Acta
M P PullesG A Verschoor


The effects of lowering the pH on Photosystem II has been studied by measuring changes in absorbance and electron spin resonance in spinach chloroplasts. At pH values around 4 a light-induced dark-reversible chlorophyll oxidation by Photosystem II was observed. This chlorophyll is presumably the primary electron donor of system II. At pH values between 5 and 4 steady state illumination induced an ESR signal, similar in shape and amplitude to signal II, which was rapidly reversed in the dark. This may reflect the accumulation of the oxidized secondary donor upon inhibition of oxygen evolution. Near pH 4 the rapidly reversible signal and the stable and slowly decaying components of signal II disappeared irreversibly concomitant with the release of bound manganese. The results are discussed in relation to the effects of low pH on prompt and delayed fluorescence reported earlier (van Gorkom, H.J., Pulles, M.P.J., Haveman, J. and den Haan, G.A. (1976) Biochim. Biophys, Acta 423, 217-226).


Dec 11, 1975·Biochimica Et Biophysica Acta·H J van GorkomJ S Wessels
Feb 16, 1976·Biochimica Et Biophysica Acta·H J van GorkomG A den Haan


Jan 1, 1986·Photosynthesis Research·S W McCauley, A Melis
Feb 1, 1990·Photosynthesis Research·J E Guenther, A Melis
Jul 3, 2013·Photosynthesis Research·Md Rafiqul IslamHiroyuki Koike
Sep 1, 1979·Proceedings of the National Academy of Sciences of the United States of America·M S DavisJ Fajer
Aug 1, 1980·Proceedings of the National Academy of Sciences of the United States of America·A Melis, J S Brown
Dec 1, 1980·Plant Physiology·J MyersR T Wang
Mar 12, 1981·Biochimica Et Biophysica Acta·A P Thielen, H J van Gorkom
Dec 6, 1976·Biochimica Et Biophysica Acta·M P PullesJ G Willemsen
Jun 1, 1984·Archives of Biochemistry and Biophysics·J Whitmarsh, D R Ort
Aug 14, 1979·Biochimica Et Biophysica Acta·J M BowesS Itoh
Nov 24, 1992·Biochemistry·C A BuserG W Brudvig

Related Concepts

Respiratory Chain
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Dark Reactions of Photosynthesis
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