Abstract
Chlorophyll a (Chl a) has been ubiquitously used in core antennas as well as in reaction centers of oxygenic photosynthesis of cyanobacteria, algae and plants. The fact suggests that chl a was indispensable for the evolution of oxygenic photosynthesis. However, a newly found cyanobacterium Acharyochloris marina uses Chl d that abosorbs 710-740nm light as the major Chl. PSI of this organism was shown to use Chl d both for antenna and a special pair P740. PS II contains a small amount of Chl a too in addition to a larger amount of Chl d. We present results on delayed fluorescence, thermoluminescence, fluorescence of Chl d of this organism as well as transient absorption and EPR spectroscopy data, and will discuss the reaction mechanism based on Chl d and evolution of PS II.
