The Electrical Potential Difference Across the Tonoplast of Root Cells

Changes in electrical potential, measured as a microelectrodewas advanced into epidermal cells and from cell to cell in rootsof Lolium multiflorum and Zea mays, are described. The recordingssuggest that the electrical potential difference between thecytoplasm and vacuole, E_vc is of the order of a few millivolts,the vacuole tending to be the more positive. E_vc appeared tobe approximately the same for epidermal, cortical, endodermal,and pericycle cells.