Functional identification of the Cl- /H+-antiporter in the membrane fraction from root cells of the halophyte Suaeda altissima (L.) Pall

The Cl− gradient dependent Cl−/H+ exchange across the membranes is identified and characterized in the plasmalemma-enriched membrane fraction isolated from roots of a halophyte Suaeda altissima. The intravesicular pH and the transmembrane electric potential changes are detected with ΔpH indicator acridine orange, pH indicator pyranine and electric potential indicator safranine O. The physiological role of the proposed Cl−/H+ antiporter is thought to maintain chloride in the cytoplasm below toxic levels under salinity conditions.