Evaluation of Indole-3-acetic Acid Decarboxylating Activity in Hypocotyl Sections of Etiolated Lupinus albus Seedlings

摘要: Summary It has been suggested that the endogenous Indole-3-acetic acid (IAA) level in plant tissues is regulated, part, by its decarboxylation. However, vivo decarboxylation assays do not permit one to attribute a definitive role this metabolic pathway control of normal growth. Therefore method was developed which 14 CO 2 collected during incubation [1- C]-IAA excised hypocotyl sections etiolated lupin ( Lupinus albus ) seedlings measure IAA purified peroxidase (HRP) utilized as model system calibrate C0 measurements well reference evaluate relative incidence metabolism sections. The evolved per mg tissue linear for 1.5 h. In period 6-15 % total produced. After temporary fall rate (from 3 h), increased again and evolution C02 detected until 20-24 an inactivation decarboxylating activity occurs enzymatic breakdown, new synthesized explain restoration percentage initial decarboxylated higher rapidly-growing hypocotyls 7 day old than non-growing 18 days. Localization section along influenced mainly at intermediate age, being apical (growing) middle (non growing) Thus correlation between cell elongation suggested.