RELATIONSHIP BETWEEN BANDING AND PHOTOSYNTHETIC ACTIVITY IN CHARA-CORALLINA AS STUDIED BY THE SPATIALLY DIFFERENT INDUCTION CURVES OF CHLOROPHYLL FLUORESCENCE OBSERVED BY AN IMAGE-ANALYSIS SYSTEM

Image analysis was applied for studying the kinetics of chlorophyll fl uorescence in the alkaline and acid zones of internodal cells of Chara corallina Klein ex Willd., in order to test the hypothesis that in th e acid bands an outward proton current yields a conversion of HCO3- io ns to CO2, thus facilitating inward diffusion of CO2. The analysis of the responses of chlorophyll fluorescence induced by changes in light intensity from 0.15 W m(-2) to 2.0 W m(-2) (lambda < 580 nm) revealed different kinetic behaviour. In the alkaline zones, the amplitude of t he variable components of fluorescence was smaller than in the acid zo nes. Curve fitting by a sum of exponentials showed that the 4 time con stants of about 2, 22, 48 and 140 s were not significantly different b etween the alkaline and acid zones. In contrast the related amplitude factors were smaller in the alkaline zones, by a factor of about 1.6 t o 2.0 in old calcified cells and by a factor of about 1.2 in young cel ls without acrustations.