ON THE FORMATION OF PHOTOSYSTEM-II CHLOROPHYLL PROTEINS AFTER A SHORT LIGHT FLASH IN ETIOLATED BARLEY LEAVES, AS MONITORED BY INVIVO FLUORESCENCE SPECTROSCOPY

The biogenesis of photosystem II (PSII) was investigated using 77 K fluorescence spectroscopy in etiolated barley leaves subjected to a millisecond flash which reduced all protochlorophyllide (Pchlide) into chlorophyllide (Chlide). In darkness after the flash, a slow chlorophyll (Chl) band shift from 682 to 684 nm was associated with the development of PSII variable fluorescence. Two Chl fluorescence bands at 678 and 687 nm were formed during the shift, the 687 nm band corresponding to the spectrum of the PSII variable fluorescence. The development of PSII fluorescence was inhibited by chloramphenicol and enhanced by cyclobeximide, suggesting a competition between plastid- and nucleus-encoded proteins for Chl binding.