title: Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings.
abstract: Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings.  In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation.  [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment.  The subsequent decrease in its specific activity was used to calculate the turnover rate.  The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h.  Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.
authors.affiliation: Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824, USA.
authors.forename: H M
authors.initials: HM
authors.lastname: Nonhebel
mesh_terms: D007210:Indoleacetic Acids / Q000378:metabolism*; D010084:Oxidation-Reduction; D000078183:Oxindoles; D010937:Plant Growth Regulators / Q000378:metabolism*; D018520:Plant Shoots / Q000378:metabolism; D013997:Time Factors; D003313:Zea mays / Q000378:metabolism*
chemical_list: D007210:Indoleacetic Acids; D000078183:Oxindoles; D010937:Plant Growth Regulators; C003013:2-oxindole-3-acetic acid; C030737:indoleacetic acid