Transcellular delta -mu H+ in Valonia ventricosa and its effect on delayed fluorescence.
The possible effect of the illumination-induced transcellular H+-gradient between the central vacuole and the external medium, on both the intensity and the kinetics of delayed fluorescence was studied by measuring both the membrane potentials and H+ fluxes across the plasmatic membranes, and the millisecond component of delayed fluorescence in single cells of the marine alga Valonia ventricosa. The kinetics of the formation of transcellular delta -mu H+ was shown to correlate with the induction kinetics of the millisecond component of delayed fluorescence. Disturbances of transcellular delta -mu H+ by electrical breakdown of the cell or by acidification of the external medium resulted in a decrease of the steady-state level of the light emission and in a decline of the minute oscillations observed in intact cells. The possible involvement of the membrane connections between the chloroplasts and the plasmatic membranes in the formation of transcellular delta-mu H+ is discussed.
Gyenes
M
M
Department of Biophysics, Faculty of Biology, Moscow State University, USSR.
D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D000460:Chlorophyta / Q000502:physiology*; D002736:Chloroplasts / Q000502:physiology / Q000648:ultrastructure; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000502:physiology / Q000648:ultrastructure; D007700:Kinetics; D008564:Membrane Potentials; D008839:Microelectrodes; D008854:Microscopy, Electron; D014617:Vacuoles / Q000502:physiology / Q000648:ultrastructure