Nitrogen and Carbohydrate Metabolism of Kidney Bean Cuttings as Affected by Treatment with Indoleacetic Acid

Abstract

1. Cuttings of kidney bean seedlings were treated by immersing their bases in 0.01 per cent indoleacetic acid for 4 hours. They were then set in sand in a propagating frame for 120 hours. During this period, in comparison with control cuttings, the treatment brought about a directional shift of large amounts of nitrogen and carbohydrates from the leaves and cotyledons to other portions of the cuttings, principally to the treated hypocotyls. 2. Accompanying this mobilization of materials, the treated cuttings responded by rapid swelling of the hypocotyls, profuse root production, and a temporary suppression of top growth. Total dry weight of the treated cuttings at the end of the rooting period was slightly less than that of the controls. 3. The responses were proportional to the length of exposure and the concentration of the acid. 4. The possible importance of indoleacetic acid as a mobilizer of food material in various other growth responses is suggested.