COMPARISON OF PRIMARY ELECTRON-TRANSFER IN PHOTOSYSTEM-II REACTION CENTERS ISOLATED FROM THE HIGHER-PLANT PISUM-SATIVUM AND THE GREEN-ALGA CHLAMYDOMONAS-REINHARDTII

We have used ultrafast spectroscopy to compare the photochemistry of P hotosystem II (PS II) reaction centres isolated from the higher plant pea, Pisum sativum, and a green alga, Chlamydomonas reinhardtii. The a pparatus now used for these experiments includes a highly sensitive mu ltichannel detector and a magic angle configuration for the pump and p robe beam polarisations. For both organisms, identical time constants were obtained for both the formation of the radical pair P680(+)Ph(-), and charge recombination from this state. We conclude that the use of the organism Chlamydomonas reinhardtii is well suited to future studi es of the primary photochemistry of genetically mutated PS II reaction centres.