Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by etiolated and green corn tissues

Journal Article · Sat Apr 01 04:00:00 EST 1989 · Plant Physiology, Supplement; (USA)

OSTI ID:6610066

Reinecke, D ^[1]

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1. Michigan State Univ., East Lansing (USA)

Etiolated corn tissues oxidase indole-3-acetic acid (IAA) to oxindole-3-acetic acid (OxIAA). This oxidation results in loss of auxin activity and may plant a role in regulating IAA-stimulated growth. The enzyme has been partially purified and characterized and shown to require O{sub 2}, and a heat-stable lipid-soluble corn factor which can be replaced by linolenic or linoleic acids in the oxidation of IAA. Corn oil was tested as a cofactor in the IAA oxidation reaction. Corn oil stimulated enzyme activity by 30% while trilinolein was inactive. The capacity of green tissue to oxidize IAA was examined by incubating leaf sections from 2 week old light-grown corn seedlings with {sup 14}C-IAA. OxIAA and IAA were separated from other IAA metabolites on a 3 ml anion exchange column. Of the IAA taken up by the sections, 13% was oxidized to OxIAA. This is the first evidence that green tissue of corn may also regulate IAA levels by oxidizing IAA to OxIAA.

• OSTI ID: 6610066
• Journal Information: Plant Physiology, Supplement; (USA), Journal Name: Plant Physiology, Supplement; (USA) Vol. 89:4; ISSN PPYSA; ISSN 0079-2241
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AUXINS
BODY
CARBON 14 COMPOUNDS
CEREALS
CHEMICAL COMPOSITION
CHROMATOGRAPHY
FRACTIONATION
GRASS
GROWTH
ION EXCHANGE CHROMATOGRAPHY
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LILIOPSIDA
MAGNOLIOPHYTA
MAIZE
METABOLISM
PLANT GROWTH
PLANT GROWTH REGULATORS
PLANT TISSUES
PLANTS
SEPARATION PROCESSES
TISSUES
TRACER TECHNIQUES