The use of microelectrodes to investigate compartmentation and the transport of metabolized inorganic ions in plants

Microelectrode measurements can be used to investigate both the intracellul ar pools of ions and membrane transport processes of single living cells, M icroelectrodes can report these processes in the surface layers of root and leaf cells of intact plants. By careful manipulation of the plant, a minim um of disruption is produced and therefore the information obtained from th ese measurements most probably represents the 'in vivo' situation. Microele ctrodes can be used to assay for the activity of particular transport syste ms in the plasma membrane of cells, Compartmental concentrations of inorgan ic metabolite ions have been measured by several different methods and the results obtained for the cytosol are compared, ion-selective microelectrode s have been used to measure the activities of ions in the apoplast, cytosol and vacuole of single cells. New sensors for these microelectrodes are bei ng produced which offer lower detection limits and the opportunity to measu re other previously unmeasured ions, Measurements can be used to determine the intracellular steady-state activities or report the response of cells t o environmental changes.