Electric Potentials and Auxin Translocation in Avena

Abstract

An improved technique for measuring electric potential differences on the etiolated Avena .coleoptile is described. An electric wave has been observed to travel down the coleoptile at a speed of up to 14 mm/hr. The wave is observed either follo-wing illumination of the intact coleoptile or following application of 3·indolylacetic acid to the cut top. The wave appears to be associated-intimately with the stream of auxin being translocated. The mechanism of auxin translocation is considered in relation to the wave. It is suggested that the electric wave may be useful as a bioassay for auxin.