Einfluß von Indolylessigsäure und Gibberellinsäure auf passive und energieabhängige Ionentransporte in Maiskoleoptilenzellen

Summary Using glass microelectrodes the influence of enhanced external ion ( K+ or Na+) concentrations on membrane potential in dwarf corn coleoptile cells is measured. From that results a modified form of the Hodgkin-Horowicz-equation, containing both the relative ion conductivity Tj and the ionic strength of the medium, is derived. Making use of this modified equation the passive and energy-dependent parts of the Tj’s are estimated from experiments in presence or absence of 0.5 mM KCN, respectively. It is found, that indoleacetic acid affects an electrogenic ion transport system, probably a proton pump, whereas gibberellic acid strongly influences the passive ion conductivity.