A cooperation of two pigment systems and respiration in photosynthetic luminescence

Abstract

Luminescence kinetics of photosynthesizing cells were investigated. This was done by measuring afterglow as a function of intensity and wavelength of actinic light as well as of temperature. In order to explain the chromatic transients, induction effects, and various other aspects of luminescence, the presence of a chloroplast respiratory “r” system was postulated. A “feedback” of products formed by photochemical “p” and “q” systems, described earlier, into the dark “r” system is believed to affect the state of reduction of cytochrome and, with it, luminescence.

The relation of luminescence to gas-exchange measurements and a possible explanation of various aspects of photosynthesis by interaction of the “p”, “q” and “r” systems is discussed.