Epr Analysis of Photosystem I Degradation During Photoinhibition of Isolated Chloroplast Membranes
As we have shown  continuous illumination of freshly isolated chloroplast membranes led to the decay of PSII activity with time, while PSI activity seemed relatively stable over the first 4–6 hours. However using previously frozen chloroplast membranes (-10° C) caused a decrease in the PSI stability and led to a decay of PSI activity during continuous illumination. This PSI decay of frozen and thawed membranes during photo-inhibition was correlated with the degradation of CPI (a chlorophyll-protein band in SDS gel electrophoresis. This suggests that PSI decay was due to the destruction of the photosystem I reaction centre.
KeywordsElectron Spin Resonance Methyl Viologen Continuous Illumination Signal Size Chloroplast Membrane
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