title: Transmembrane electrical potentials in growing maize roots : Anti-auxin effects.
abstract: The anti-auxin 4-chlorophenoxyisobutyric acid (PCIB) applied at a concentration of 10(-2) mol m(-3) to maize root segments was found to induce a transmembrane electrical potential of up to-130 mV (Δpd of 30 mV). The kinetics of this response were comparable to the time scale for PCIB-stimulated H(+)-extrusion. Both effects are eliminated by the addition of p-fluoromethoxycarbonyl cyanide phenylhydrazone (FCCP). Treatment with fusicoccin (FC) and PCIB together does not result in a hyperpolarization greater than with FC alone. Benzoic acid (10(-2) mol m(-3)) had no effect on the transmembrane electrical potentials. These results are discussed in relation to a possible electrogenic proton pump which may be regulated by perturbations in the cellular auxin content or activity.
authors.affiliation: Institut de Biologie et de Physiologie Végétales, Université de Lausanne, Place de la Riponne 6, CH-1005, Lausanne, Switzerland.
authors.forename: M M
authors.initials: MM
authors.lastname: Moloney
authors.forename: P E
authors.initials: PE
authors.lastname: Pilet
authors.forename: M T
authors.initials: MT
authors.lastname: Marrè
authors.forename: G
authors.initials: G
authors.lastname: Romani