Changes in the levels of abscisic acid and its metabolites in excised leaf blades of Xanthium strumarium during and after water stress

Journal Article · Wed Oct 01 00:00:00 EDT 1980 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.66.4.672· OSTI ID:6719032

Zeevaart, J A.D.

The time course of abscisic acid (ABA) accumulation during water stress and of degradation following rehydration was investigated by analyzing the levels of ABA and its metabolites phaseic acid (PA) and alkalihydrolyzable conjugated ABA in excised leaf blades of Xanthium strumarium. Initial purification was by reverse-phase, preparative, high performance liquid chromatography (HPLC) which did not require prior partitioning. ABA and PA were purified further by analytical HPLC with a ..mu..Bondapak-NH/sub 2/ column, and quantified by GLC with an electron capture detector. The ABA content of stressed leaves increased for 4 to 5 hours and then leveled off due to a balance between synthesis and degradation. Since PA accumulated at a constant rate throughout the wilting period, it was concluded that the rate of ABA synthesis decreased after the first 4 to 5 hours stress. Conjugated ABA increased at a low rate during stress. This is interpreted to indicate that free ABA was converted to the conjugated form, rather than the reverse. Following rehydration of wilted leaves, the ABA level immediately ceased increasing; it remained constant for 1 hour and then declined rapidly to the prestress level over a 2- to 3-hour period with a concomitant rise in the PA level. In contrast to the rapid disappearance of ABA after relief of stress, the high PA content of rehydrated leaves declined only slowly. The level of conjugated ABA did not change following rehydration, indicating that conjugation of ABA was irreversible. Detached Xanthium leaves that were subjected to a wilting-recovery-rewilting cycle in darkness responded to the second wilting period by formation of the same amount of ABA as accumulated after the first stress period.

• Research Organization: Michigan State Univ., East Lansing, MI (United States)
• DOE Contract Number: EY-76-C-02-1338
• OSTI ID: 6719032
• Journal Information: Plant Physiol.; (United States), Vol. 66:4
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
HORMONES
BIOCHEMICAL REACTION KINETICS
LEAVES
BIOLOGICAL STRESS
METABOLITES
WEEDS
SENSITIVITY
BIOLOGICAL PATHWAYS
BUILDUP
HYDROLYSIS
LIQUID COLUMN CHROMATOGRAPHY
METABOLISM
PH VALUE
QUANTITY RATIO
TIME DEPENDENCE
VEGETATIVE PROPAGATION
WATER
CHEMICAL REACTIONS
CHROMATOGRAPHY
CLONING
DECOMPOSITION
HYDROGEN COMPOUNDS
KINETICS
LYSIS
OXYGEN COMPOUNDS
PLANTS
REACTION KINETICS
SEPARATION PROCESSES
SOLVOLYSIS
550500* - Metabolism
550200 - Biochemistry