INDOLE-3-BUTYRIC ACID IN ARABIDOPSIS-THALIANA .2. IN-VIVO METABOLISM

Indole-3-butyric acid (IBA) was metabolized by seedlings of Arabidopsi s thaliana cultivated in liquid medium under sterile conditions to two major metabolites. One metabolite was hydrolyzed by 1 N NaOH and beta -glucosidase and was tentatively identified as IBA-glucose and the oth er was hydrolyzed by 7 N NaOH and amidase and was identified as an ami de-linked conjugate. IBA-glucose synthase activity was found in a solu ble enzyme fraction after incubation of H-3-IBA, IBA and UDP-glucose. The labelled reaction product had an R(f) value comparable to IBA gluc ose and stained positive with Ehmann reagent.