Related Experiment Video
Updated: Aug 8, 2026

Measuring Gene Expression in Bombarded Barley Aleurone Layers with Increased Throughput
Published on: March 30, 2018
Abscisic alcohol is an intermediate in abscisic Acid biosynthesis in a shunt pathway from abscisic aldehyde
C D Rock1, T G Heath, D A Gage
1Michigan State University-Department of Energy Plant Research Laboratory, East Lansing, Michigan 48824.
Abstract:
It has previously been shown that the abscisic acid (ABA)-deficient flacca and sitiens mutants of tomato are impaired in ABA-aldehyde oxidation and accumulate trans-ABA-alcohol as a result of the biosynthetic block (IB Taylor, RST Linforth, RJ Al-Naieb, WR Bowman, BA Marples [1988] Plant Cell Environ 11: 739-745). Here we report that the flacca and sitiens mutants accumulate trans-ABA and trans-ABA glucose ester and that this accumulation is due to trans-ABA biosynthesis. (18)O labeling of water-stressed wild-type and mutant tomato leaves and analysis of [(18)O]ABA by tandem mass spectrometry show that the tomato mutants synthesize a significant percentage of their ABA and trans-ABA as [(18)O]ABA with two (18)O atoms in the carboxyl group. We further show, by feeding experiments with [(2)H(6)]ABA-alcohol and (18)O(2), that this doubly-carboxyl-labeled ABA is synthesized from [(18)O]ABA-alcohol with incorporation of molecular oxygen. In vivo inhibition of [(2)H(6)]ABA-alcohol oxidation by carbon monoxide establishes the involvement of a P-450 monooxygenase. Likewise, carbon monoxide inhibits the synthesis of doubly-carboxyl-labeled ABA in (18)O-labeling experiments. This minor shunt pathway from ABA-aldehyde to ABA-alcohol to ABA operates in all plants examined. For the ABA-deficient mutants impaired in ABA-aldehyde oxidation, this shunt pathway is an important source of ABA and is physiologically significant.
More Related Videos
08:52A Seed Coat Bedding Assay to Genetically Explore In Vitro How the Endosperm Controls Seed Germination in Arabidopsis thaliana
Published on: November 9, 2013
07:08Identification of Novel Regulators of Plant Transpiration by Large-Scale Thermal Imaging Screening in Helianthus Annuus
Published on: January 30, 2020
Related Concept Videos
Aldehydes and Ketones with Alcohols: Hemiacetal Formation
Respiration Pathways
Acid Halides to Esters: Alcoholysis
Glycolysis: Preparatory Phase
The Citric Acid Cycle: Output
Regulation of Citric Acid Cycle
The citric acid cycle is regulated in several ways, including feedback inhibition, regulation of enzyme activities, and associated anaplerotic or cataplerotic pathways.
The primary substrate of the TCA cycle—acetyl CoA—is produced by the...
Preparation of Alcohols via Addition Reactions
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...