Relationship of Dissociation of Cellular Proteins by Auxins to Growth

Abstract

The centrifuge method was used to determine protoplasmic viscosity in cortex cells (and in some instances in ray and pith cells) of bean petioles and stems which had been daubed with lanolin prepns. of indole-3-acetic acid, indole-3n-propionic acid, and a naphthalene acetic acid. Unilateral applications of the growth substances initially conditioned negative curvatures, in which instances the viscosity was lower in cells on the faster growing sides of the petioles and stems than in cells on the slower growing sides, and likewise lower than in comparable control cells. When subsequent positive bend-ings resulted, viscosity was decreased about equally on the treated and untreated sides, except in the case of petioles treated with a mixture of 100 mg. of indole-3n-propionic acid per g. of lanolin, in which instance the viscosity was lower on the untreated sides. Applications of indole-3n-propionic acid or a naphthalene acetic acid to the tops of decapitated plants resulted in a decrease in the structural viscosity of protoplasm in cells below the cut surfaces. In part, at least, the decreases in structural viscosity were conditioned by dissociations of cellular proteins. Biochemical and thermo-dynamical evidence is introduced which suggests that such dissociations condition increased protoplasmic swelling pressure, respiration, and polysaccharide hydrolysis, as well as altering development.