Ionic Relations of Cells of Chara Australis Xi. Chloride Fluxes

Influx and efflux of chloride ions in Ohara australis have been measured under a variety of conditions in an attempt to relate the active transport inwards to a particular aspect of metabolism. Influx across the plasmalemma in single cells was 1-4 p-equiv_ cm-2 sec-I. The rate constant for exchange of cytoplasmic chloride was of the order of 10-3 sec-1 and the content of chloride in the cytoplasm was found to be about 100 n-equiv. cm-2? From these values the influx across the tonoplast was inferred to be ~ 100 p-equiv. cm-2 sec-I. Most of the cytoplasmic chloride was probably in the chloroplasts.