The induction of free proline accumulation by endogenous ABA in Arabidopsis thaliana during drought

Conference · Wed May 01 04:00:00 EDT 1991 · Plant Physiology, Supplement; (United States)

OSTI ID:5517205

Gottlieb, M L; Bray, E A ^[1]

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1. Univ. of California, Riverside (United States)

Endogenous levels of abscisic acid (ABA) and free proline increase in response to drought stress. Exogenous ABA has been shown to induce proline accumulation, suggesting that ABA triggers the amino acid response. To determine if endogenous ABA induces free proline accumulation, increases in ABA and proline during drought stress were compared between wild type (WT), ABA-insensitive (abi) and ABA-deficient (aba) mutants of Arabidopsis thaliana. If elevated levels of endogenous ABA signal the proline response, then the mutants would not be expected to accumulate proline during stress. abi should be unable to respond to increased levels of endogenous ABA, while aba should be unable to accumulate sufficient ABA to elicit a proline response. Drought-stressed three week old shoots of WT, abi, and aba exhibited different patterns of endogenous ABA accumulation, but similar patterns of proline accumulation over 24 hours. Although the patterns of endogenous ABA accumulation differed, maximum levels were similar in WT and abi, but aba produced approximately 25% less. However, free proline accumulated in all three plant lines. abi exhibited a greater, more rapid increase in free proline over that in either WT or aba. aba, however, showed the same pattern and levels of accumulation as that in WT. Since free proline accumulated to at least similar levels in both WT and mutants, regardless of the levels of ABA accumulation, it may be that only a small endogenous ABA accumulation is required for proline accumulation. Alternatively, endogenous ABA may not be the direct signal for the proline response during drought stress.

• OSTI ID: 5517205
• Report Number(s): CONF-9107184--
• Conference Information: Journal Name: Plant Physiology, Supplement; (United States) Journal Volume: 96:1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540210* -- Environment
Terrestrial-- Basic Studies-- (1990-)
ABSCISIC ACID
AMINES
AMINO ACIDS
ARABIDOPSIS
AUXINS
AZOLES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BIOLOGICAL STRESS
CARBOXYLIC ACIDS
DROUGHTS
ENVIRONMENTAL EFFECTS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
KINETICS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYSIOLOGY
PLANT GROWTH REGULATORS
PLANTS
PROLINE
PYRROLES
PYRROLIDINES
REACTION KINETICS