Auxin catabolism and inhibitors in normal and crown gall tissues of Impatiens balsamina

Abstract

Indoleacetic acid-like substances and hydronaphthoquinoneglucoside concentrations are higher in crown gall and other tissues of infected Impatiens balsamina than in corresponding tissues of non-infected plants.No difference can be found in indoleacetic acid (IAA) synthesizing capacity (from tryptophan) between tissues of normal and tumorous plants.Peroxidase and IAA oxidase in purified extracts of crown gall tissue are higher than in other tissues but only during the first stages of its development. Subsequently, their activity decreases while it continues to increase in leaves and stem.The results suggest participation of IAA oxidase inhibitors, particularly 1,2,4-trihydroxynaphthalene-4-glucoside, in establishing the higher IAA content of crown gall tissues.