Kinetic characterization of T-jump thermoluminescence in isolated chloroplasts

Luminescence triggered by temperature jump in lettuce chloroplasts was measured at different final temperatures in the range of 30–70 °C. The initial temperature was 20 °C. This type of luminescence is suggested to result from a reaction of recombination of precursors formed during the preillumination period. The rate constant for this second order reaction was derived and shown to be proportional to the ratio between the luminescence peak and the total luminescence integral. An Arrhenius plot for these rate constants yields the value of 0.68 ± 0.08 eV for the activation energy. This value is compared with those reported by other investigators and a mechanism in terms of the semi conductor concepts is proposed for luminescence.