Abstract
According to the study of PSII particle action-spectra of Huzisige and Yamamoto (Plant & Cell Physil.,14:
953-963(1973)), Tris-inactivated chloroplasts were inhibited in O2-evolving center and electron transport between Qa and Qb of PSII. This study detected the inhibition between Qa and Qb in Tris-washed and photo-reactivated chloroplasts by using fluorescence meter with powerful blue-light emitting diode, active to rise maximum stable emission in less than 50 μsec. The photo-eactivated chloroplasts recovered O2-evolving activity 50%, and kept 70% of Qa-photoreducing activity (the chlorophyll fluorescence rise in 0-1 msec after blue-light spark in the presence of DCMU). While the Qb-photoreducing and fluores-
cence risig activity of reactivated chloroplsts at 20 msec without DCMU was depressed to 8-16% of normal chloroplasts caused by the inhibition between Qa and Qb.
