Indoleacetic Acid and the Utilization of Radioactive Pyruvate and Acetate by Wheat Roots.

Open Access
Publisher Website
Google Scholar
Abstract
In concentrations that inhibit growth (1 x 10-4 and 2.5 x 10-5 [image]) indole-acetic acid (IAA) inhibits absorption of C14-labeled pyruvate and acetate by excised wheat seedling roots. When allowance for the effect on absorption is made, it is evident that distribution of these labeled substances into various metabolic pathways is affected by the auxin. Incorporation of activity from pyruvate-2-C14 into malic acid, soluble sugars, cell wall materials soluble in 4% NaOH and CO2 is inhibited. Synthesis of a-cellulose is enhanced by the auxin. Formation of pectic substances and polyuronide hemicelluloses from acetate-1-C14 is in-hibited while synthesis of a -cellulose is stimulated at the 2 concentrations of IAA used. With the higher concentration of IAA, conversion of acetate to non-cellulosic polysaccharides and CO2 is restricted.