Effects of different external potassium concentrations on potassium concentrations in the cytoplasm of maize root cortical cells

Summary Direct measurements of potassium concentrations within individual cells are few in number. In the present study, potassium concentrations within the cytoplasm of Zea mays root cortical cells grown in the presence of 1, 6 or 20 mol m −3 potassium were determined by X-ray microanalysis. While it was observed that the mean cytoplasmic potassium concentrations were maintained around 140 mol m -3 independent of the external potassium, there were variations in K + concentrations between and within cells.