Abscisic acid biosynthesis in water-stressed leaves
Although abscisic acid (ABA) was discovered 30 years ago, very little is known about its biosynthetic pathway in higher plants. Two hypotheses have been proposed: (i) a direct pathway involving only C-15 intermediates like farnesyl pyrophosphate, (ii) an indirect pathway involving C-40 intermediates like the xanthophylls. When {sup 14}CO{sub 2} was fed into greened bean plants, the {sup 14}C specific activity of ABA was always lower than those in xanthophylls, such as violaxanthin and lutein, regardless of {sup 12}CO{sub 2} chase periods. The ABA accumulation in green leaves was not affected by fluridone when plants were stressed once, but the {sup 14}C incorporation into ABA was inhibited to the same extent as those of xanthophylls. The incorporation of {sup 18}O into the ABA ring when violaxanthin was labeled by {sup 18}O in vivo via the violaxanthin cycle indicates that at least a portion of ABA was derived from {sup 18}O-labeled violaxanthin during water stress.
- Research Organization:
- State Univ. of New York, Syracuse, NY (USA). Coll. of Environmental Science and Forestry
- OSTI ID:
- 6555341
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Abscisic acid biosynthesis in leaves and roots of Xanthium strumarium
Violaxanthin is an abscisic acid precursor in water-stressed dark-grown bean leaves
Related Subjects
ABSCISIC ACID
BIOSYNTHESIS
BIOLOGICAL PATHWAYS
BIOLOGICAL ACCUMULATION
BIOLOGICAL STRESS
CARBON 14 COMPOUNDS
LEAVES
OXYGEN 18
PHASEOLUS
TRACER TECHNIQUES
WATER
AUXINS
CARBOXYLIC ACIDS
EVEN-EVEN NUCLEI
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LEGUMINOSAE
LIGHT NUCLEI
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MONOCARBOXYLIC ACIDS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PLANT GROWTH REGULATORS
PLANTS
STABLE ISOTOPES
SYNTHESIS
550501* - Metabolism- Tracer Techniques
551001 - Physiological Systems- Tracer Techniques
550201 - Biochemistry- Tracer Techniques