[Theoretical study of fluorescence of photosynthetic pigments at complex dependence of intensity of exciting light on time].

Now the methods using the radiance with complex dependence of light intensity on time are applied to research of photosynthesis by means of fluorescence, exciting photosynthetic pigments. One of these methods is applied in PAM-fluorometers--the commercial devices currently widely used to investigate a state of photosynthesizing systems. However, if excitation is performed in this way, the question, what components of fluorescence are registered at an output of such devices, remains to be open-ended. In this work an attempt to analyse this task has been made.

[A theoretical discussion on oscillations of concentrations of P700+ and the intermediates of the Calvin-Benson cycle].

A theoretically obtained oscillatory mode caused by long-wave illumination is discussed. Repetitive variations in the performance of photosystem I, the electron transport chain, and the Calvin-Benson cycle take place in this mode. The corresponding alterations of photosystem II performance are not repetitive. Damped oscillations of P700+ concentration and CO2 assimilation rate are observed on the theoretical curves. The oscillations of the photosystem I variables of the model look similar to the P700+ concentration dependences derived earlier during experiments on registration of photosystem I EPR signal at different temperatures.