The effect of excitation on the rate of respiration in the liverwort <i>Conocephalum conicum</i>

Abstract

Simultaneous measurements were taken of the electrical activity and the rate of respiration of thalli of Conocephalum conicum L. stimulated electrically and mechanically (by cutting). The measurements of the rate of respiration employed a modified Warburg apparatus for O 2 consumption and an infra‐red gas analyzer with computer recording and data processing for CO 2 evolution. The action potential, produced by either a cut (a damaging stimulus) or an electrical stimulus (a non‐damaging stimulus), caused a transient rise in the rate of respiration. The course of changes in the rate of respiration depends on the character of the excitation and the area of the thallus covered by it. If stimulation does not produce excitation, the increase in the rate of respiration does not take place, regardless of the magnitude and type of the stimulus applied.