Fluorescence induction, in chloroplasts isolated from the green alga, Bryopsis maxima I. Occurrence of the complete Kautsky effect in Bryopsis chloroplasts

Abstract

The induction of chlorophyll a fluorescence in dark-adapted cells of the green alga, Bryopsis maxima, showed a complex time course featured by the presence of four transient peaks or shoulders. All transient features in the fluorescence induction were fully reproducible in cell free systems of the alga: the protoplasts and intact chloroplasts showed a fast biphasic rise as well as subsequent slow changes with two transient peaks in the fluorescence yield. The kinetic pattern of the induction in intact chloroplasts varied with the intensity of excitation light. The slower transient largely disappeared on osmotic rupture of the chloroplast envelope. It appears that Bryopsis chloroplasts are the first cell free preparation in which a complete Kautsky effect can be observed and, therefore, provide a unique and useful material for the study of slow complex transients in fluorescence induction.