plant hormone that stimulates stomatal closure and promotes seed and bud dormancy. Inhibits shoot growth but may promote root growth. Plays a role in wounding responses and in abscission ~ of leaves and fruit.
Merriam-Webster Online Dictionary
abscisic acid (noun)a plant hormone CHO that is a sesquiterpene widespread in nature and that typically promotes leaf abscission and dormancy and has an inhibitory effect on cell elongation - 15 20 4
abscisic acid (Wikipedia)
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| Names | |
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| Systematic 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 | B00898 |
| Abbreviations | ABA |
| 2698956 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.040.275 |
| EC Number | 244-319-5 |
| MeSH | Abscisic+Acid |
PubChem CID
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| RTECS number | RZ2475100 |
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 | |
| S-phrases (outdated) | S22, S24/25 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
 verify (what is   ?)
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| Infobox references | |
Abscisic acid (ABA) 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.