ELECTRICAL AND CURVATURE RESPONSES OF THE AVENA COLEOPTILE TO TRANSVERSELY APPLIED DIRECT CURRENT

Publisher Website
Google Scholar
Abstract
An investigation of the effects of transversely applied direct current on the electrical polarity and curvature of the Avena coleoptile. Ten amperes applied for 10 min. to any 2 mm. longitudinal section of the coleoptile establishes a transverse electrical polarity and causes the coleoptile to bend. The initial bending, in and above the contact region, is toward the electropositive pole of the current applying circuit. This is followed by a 2d bending, which is basal to the contacts and toward the negative side of the coleoptile. The data further show that as the distance between the apex and the current applying contacts is increased, the amt. of curvature induced by the given current decreases, but the time required to attain the max. curvature in the initial direction increases. The curvature which was studied is due to growth phenomena and not to turgor changes. Maximum electrical response is induced by the given current when it is applied more than 5 mm. below the apex. The magnitude of the transverse electrical polarity and the time course of the electrical changes are not dependent on the distribution of the growth hormones.