Inactivation of Oxygen Evolving Activity of PS II Membranes by Hydroxyurea
EPR signals of SIIs and SIIf in PS II membranes were suppressed by tyrosine radical scavengers such as hydroxyurea (HU) and pyrogallol (PY). HU and PY inhibited oxygen evolution and released three of four Mn in PS II membranes without affecting the polypeptide composition. The inhibition of oxygen evolution was enhanced under the light and accelerated by the addition of dimethylbenzoquinone. The HU-treated PS II membranes could photoreduce DCIP on addition of DPC.
KeywordsChlorophyll Fluorescence Oxygen Evolution Ascorbate Peroxidase Actinic Light Pulse Amplitude Modulate
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