Analysis of the Variation Potential Induced by Wounding in Plants

摘要

Following burning of a leaf portion, a bioelectrical wave called“variation potential”spread throughout the whole plant. Bioelectrical variations are recorded by two types of electrodes (platinum wires and Ag/AgCl nonpolarizable electrodes) in the stem ofVicia fabaand in the petiole ofLycopersicon esculentumandMimosa pudica. The time course of the variation potential thus recorded can be divided into two components respectively called components“A”and“B”. Component A looks like a negative spiky bioelectrical change lasting about 1 min with an amplitude of 20–50 mV spreading in front of the component B depicted by a more smooth and long-lasting (several min) wave of negativity. An attenuation of the signals recorded under the Ag/AgCl electrodes is noted compared to that recorded under the platinum wires. Moreover, component B is more attenuated than the component A. Attenuation of the component A is nearly the same as that noted for the action potential inMimosa pudica.All the parameters depicting the variation potential increase approximately in direct proportion to the amount of the damaged area up to 400 mm2inVicia faba; above this value, a maximal respon