Abstract: | The inhibition of indoleacetic acid oxidase activity by chlorogenic acid is markedly variable. Aqueous extracts of acetone precipitates from etiolated pea epicotyls contain heat-stable substances which decrease the inhibition produced by chlorogenic acid and also have a small activating effect. Low concentrations of pcoumaric acid (1 micro/ml) can stimulate this action. The possible role of activators and inhibitors in the in vivo regulation of indoleacetic acid oxidase activity is discussed. |