How characean cells have contributed to the progress of plant membrane biophysics

Abstract

Basic knowledge on plant membranes has been greatly indebted to internodal cells of charophytes, which are aquatic cryptogams mostly growing in fresh water and some in brackish water. The huge size of the internodal cell enables us to study water and ion transport in a single cell. Furthermore, the cell can be subjected to various kinds of cell operations such as preparation of cells having abnormal osmotic pressures, effusion of the steaming endoplasm, perfusion of the vacuole with artificial solutions, preparation of tonoplast-free cells and plasma membrane-permeabilised cells. Taking advantage of the large cell size and the cell operation techniques, various aspects of characterisations of plant membranes (plasma membrane, tonoplast, endomembranes) have been achieved using characean cells. The present article intends to depict unique contributions of characean cells to membrane physiology and biophysics in the last century, focusing on several topics and with historical perspectives.