**Discovery and Identification**:
– Torsten Hemberg observed the correlation between rest periods and growth inhibitors in potato tubers.
– Frederick T. Addicott and Larry A. Davis identified abscisic acid as a plant hormone in 1963.
– Abscisin I and II were initially isolated, with II later recognized as abscisic acid (ABA).
**Role in Plants**:
– ABA functions in plant stress and pathogen responses.
– ABA production in terminal buds prepares plants for winter and responds to decreased soil water potential.
– ABA inhibits stomatal opening to reduce water loss, seed germination, and maintains dormancy.
– ABA affects lateral root development, fruit ripening, and seed dormancy.
**Biosynthesis, Effects, and Signal Cascade**:
– ABA is synthesized in the plastidal MEP pathway and various plant tissues in response to stress.
– ABA can be catabolized to phaseic acid for homeostasis.
– ABA induces stomatal closure, promotes root growth in low humidity, and affects root growth under salty conditions.
– ABA binds to PYR1, activates SnRK2s, and regulates gene expression, including ABA-responsive genes like ABF family transcription factors.
**Applications and Medicinal Benefits**:
– ABA is found in metazoans, including humans, with anti-inflammatory and anti-diabetic effects.
– ABA is studied for its biological effects as a potential nutraceutical or drug.
– ABA has been linked to peroxisome proliferator-activated receptor activation and inflammation regulation.
– Understanding ABA mechanisms can lead to therapeutic advancements in animals and humans.
**Research, Implications, and Future Directions**:
– Research on ABA gene clusters, pathways, and YL-related proteins is ongoing.
– ABA has antiviral properties, serves as a pathogen effector, and immune regulator in plants.
– Monitoring ABA levels aids in understanding plant responses to stress, and FRET technology enhances real-time monitoring.
– Future directions may involve exploring novel mechanisms in plant biology, developing stress-resistant crops, elucidating plant hormone crosstalk, and applying FRET technology in other plant signaling pathways.
Abscisic acid (ABA or abscisin II) is a plant hormone. ABA functions in many plant developmental processes, including seed and bud dormancy, the control of organ size and stomatal closure. It is especially important for plants in the response to environmental stresses, including drought, soil salinity, cold tolerance, freezing tolerance, heat stress and heavy metal ion tolerance.
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Names | |
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Preferred IUPAC name
(2Z,4E)-5-[(1S)-1-Hydroxy-2,6,6-trimethyl-4-oxocyclohex-2-en-1-yl]-3-methylpenta-2,4-dienoic acid | |
Other names
(2Z,4E)-(S)-5-(1-Hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexen-1-yl)-3-methyl-2,4-pentanedienoic acid; Dormic acid;[citation needed] Dormin
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Identifiers | |
3D model (JSmol)
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3DMet | |
Abbreviations | ABA |
2698956 | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.040.275 |
EC Number |
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MeSH | Abscisic+Acid |
PubChem CID
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RTECS number |
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
C15H20O4 | |
Molar mass | 264.321 g·mol−1 |
Appearance | Colorless crystals |
Density | 1.193 g/mL |
Melting point | 163 °C (325 °F; 436 K) |
log P | 1.896 |
Acidity (pKa) | 4.868 |
Basicity (pKb) | 9.129 |
Hazards | |
GHS labelling: | |
Warning | |
H315, H319, H335 | |
P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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