An oscillatory component of propagated fluctuation electric potential in lupine shoot

Abstract

Application of a drop of auxin solution to a cut surface on the petiole in lupine shoot elicits a travelling pulse of electric potentia) decrease. This pulse was simulta­neously recorded by means of a DC amplifier and band-pass amplifier 0.1-100 Hz, both connccted to the same exploring AgCI electrode driven into the stem. The DC record shows a pulse 20-80 mV in height of about 30 s duration at its height with smooth slopes. The band-pass amplifier shows one to a few pairs of spikes (negative and positive) whose amplitude is at least of an order lower than that of the DC pulse. Thcse spikcs are interpretcd as the action potentia) of certain excitable cclls rccorded in a --volume conductor"·. The pulse is interpreted as a wave of cooperative depolarization of excitable and a mass of inexcitable cells.