Figure 4.

Intracellular K concentrations and pH in epidermal root cells of low-K Arabidopsis plants. A, Distribution frequency of intracellular concentrations of K determined in 2-week-old plants by impalement with K-selective microelectrodes (n = 37 plants). B, Distribution frequency of intracellular pH determined by impalement with pH-selective microelectrodes (n = 20 plants). C, K concentration and pH within a particular range of simultaneously measured membrane potentials. Means ± se of measurements in individual plants are shown in black for K (mm) and in white for pH.