Relationship of Dissociation of Cellular Proteins by Auxins to Growth

Abstract

1. 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 preparations of indole-3-acetic acid, indole-3n-propionic acid, and α-naphthalene acetic acid. 2. Unilateral applications of the growth substances initially conditioned negative curvatures, in which instances the protoplasmic 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 control petioles or stems. When subsequent positive curvatures resulted, the viscosity was decreased about equally on the treated and untreated sides, except in the case of petioles treated with a paste containing 100 mg. of indole-3n-propionic acid per gram of lanolin, in which instance the viscosity was lower on the untreated sides. 3. Applications of indole-3n-propionic acid or α-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. 4. In part at least, the decreases in structural viscosity were conditioned by dissociations of cellular proteins; that is, by the splitting of proteins into molecules one-half, one-fourth, one-eighth, etc., that of the original ones. 5. Biochemical and thermodynamical evidence is introduced which suggests that such dissociations condition increased protoplasmic swelling pressure, respiration, and polysaccharide hydrolysis, as well as altering development.