Modulating Effects on the Delayed Luminescence from Photosystem II of Photosynthesis

Abstract

A glance at the literature will reveal quite a few papers which report that delayed luminescence from isolated chloroplasts varies in a parallel way to the variations in the fluorescence yield (1–3). On the other hand several papers (4–8) report variation (an increase) of the delayed luminescence with the development of the “high energy state” of photophosphorylation (pH gradient and membrane potential). The impression from these (4–6) reports is however the absence of a clear-cut correlation to the fluorescence. Most of the above reports give data on delayed luminescence measurement at a particular point of time of its decay (i.e. at around 1 msec.). It is important to be able to scan the dependence of delayed luminescence on the fluorescence yield and other parameters over a large proportion of its decay curve, and to establish the conditions for simple relations between the delayed luminescence, fluorescence yield and other parameters. This is one of the purposes of this report.