A Quantitative Study of the Effect of Anions on the Permeability of Plant Cells

Although the effects of cations on the permeability of plant cells have frequently been studied, comparatively little attention has been paid to the action of anions. The writer has investigated the effects of a series of anions on the permeability of Laminaria agardhii Kjellm. Measurements were made of the electrical conductivity by the method described by Osterhout. x The salts were the purest obtainable and the distilled water was not toxic to delicate test objects. The salt solutions were neutral to phenolsulfonephthaleln (pH 7 ± 0.5). The temperature during the course of the experiments was 19 42°C. Sodium sulfocyanide, iodide, nitrate, bromide, chloride, acetate, sulfate, tartrate, phosphate, and citrate were selected for study. Solutions of these salts were made of the same conductivity as a slightly diluted sea water solution; ~/z., a solution having the same conductivity as a 0.51 ~ solution of sodium iodide. (Normal sea water has the same conductivity as a 0.57 ~ solution of sodium iodide.) As is well known, various samples of sea water differ slightly in their conductivity and hence no absolute concentration can be given for each salt. The following table shows the approximate concentrations used.