Gibberellin (GA) biosynthesis in elongating internodes Zea mays (maize): The 3. beta. -hydroxylase

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

OSTI ID:6873600

Spray, C R; Phinney, B O ^[1]; Gaskin, P; MacMillan, J ^[2]

---

1. Univ. of California, Los Angeles (USA)
2. Univ. of Bristol (England)

The early-13-hydroxylation pathway for GA biosynthesis in maize leads to GA{sub 1}, the main GA responsible for shoot elongation. Growth response data, double-labeled feeding studies and endogenous GA levels suggest that the dwarf-1 mutant blocks the step GA{sub 20}to GA{sub 1}. We are screening for a system from maize from which we can purify the 3{beta}-hydroxylase and study its physical and biological properties. We find that diced internodal tissues will metabolize ({sup 13}C, {sup 3}H)-GA{sub 20} to ({sup 13}C, {sup 3}H)-GA{sub 1} and ({sup 13}C, {sup 3}H)-GA{sub 29} with metabolism as high as 80%. A cell free system from this material will give 5% metabolism. In a typical experiment 1g of internodal tissue is frozen in liquid nitrogen and macerated in 0.1M Tris plus cofactors. The homogenate is centrifuged at 15000 x g for 30 min at 4{degrees}C and the supernatant used for metabolic studies.

• OSTI ID: 6873600
• Journal Information: Plant Physiology, Supplement; (USA), Vol. 89:4; ISSN 0079-2241
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GIBBERELLIC ACID
METABOLISM
HYDROXYLASES
ENZYME ACTIVITY
MAIZE
PLANT GROWTH
PLANT STEMS
ELONGATION
BIOLOGICAL PATHWAYS
CARBON 13
GAS CHROMATOGRAPHY
METABOLITES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
CARBON ISOTOPES
CARBOXYLIC ACIDS
CEREALS
CHROMATOGRAPHY
ENZYMES
ESTERS
EVEN-ODD NUCLEI
GRASS
GROWTH
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXY ACIDS
ISOTOPE APPLICATIONS
ISOTOPES
LACTONES
LIGHT NUCLEI
LILIOPSIDA
MAGNOLIOPHYTA
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PLANTS
SEPARATION PROCESSES
STABLE ISOTOPES
550501* - Metabolism- Tracer Techniques