Gibberellic acid

Gibberellic acid (also called gibberellin A3, GA, and GA3) is a hormone found in plants and fungi.[1] Its chemical formula is C19H22O6. When purified, it is a white to pale-yellow solid.

Gibberellic acid
Gibberellic acid.svg
IUPAC name
(3S,3aS,4S,4aS,7S,9aR,9bR,12S)-7,12-Dihydroxy-3-methyl-6-methylene-2-oxoperhydro-4a,7-methano-9b,3-propenoazuleno[1,2-b]furan-4-carboxylic acid
3D model (JSmol)
ECHA InfoCard 100.000.911
EC Number
  • 201-001-0
Molar mass 346.379 g·mol−1
Melting point 233 to 235 °C (451 to 455 °F; 506 to 508 K) (decomposition)
5 g/L (20 °C)
Irritant (Xi)
R-phrases (outdated) R36
S-phrases (outdated) R26, S36
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Plants in their normal state produce large amounts of GA3. It is possible to produce the hormone industrially using microorganisms.[2] Gibberellic acid is a simple gibberellin, a pentacyclic diterpene acid promoting growth and elongation of cells. It affects decomposition of plants and helps plants grow if used in small amounts, but eventually plants develop tolerance to it.[citation needed] GA stimulates the cells of germinating seeds to produce mRNA molecules that code for hydrolytic enzymes. Gibberellic acid is a very potent hormone whose natural occurrence in plants controls their development. Since GA regulates growth, applications of very low concentrations can have a profound effect while too much will have the opposite effect.[3] It is usually used in concentrations between 0.01 and 10 mg/L.[citation needed]

GA was first identified in Japan in 1926, as a metabolic by-product of the plant pathogen Gibberella fujikuroi (thus the name), which afflicts rice plants. Fujikuroi-infected plants develop bakanae ("foolish seedling"), which causes them to rapidly elongate beyond their normal adult height. The plants subsequently lodge due to lack of support, and die.[2]

Gibberellins have a number of effects on plant development. They can stimulate rapid stem and root growth, induce mitotic division in the leaves of some plants, and increase seed germination rates.[4]

Gibberellic acid is sometimes used in laboratory and greenhouse settings to trigger germination in seeds that would otherwise remain dormant.[3] It is also widely used in the grape-growing industry as a hormone to induce the production of larger bunches and bigger grapes, especially Thompson seedless grapes. In the Okanagan and Creston valleys, it is also used as a growth regulator in the cherry industry. It is used on Clementine Mandarin oranges, which may otherwise cross-pollinate with other citrus and produce undesirable seeds. Applied directly on the blossoms as a spray, it allows for Clementines to produce a full crop of seedless fruit.

GA is widely used in the barley malting industry. A GA solution is sprayed on the barley after the steeping process is completed. This stimulates growth in otherwise partly dormant kernels and produces a uniform and rapid growth.

See alsoEdit


  1. ^ Silva ALL, Rodrigues C, Costa JL, Machado MP, Penha RO, Biasi LA, Vandenberghe LPS, Soccol CR (2013). "Gibberellic acid fermented extract obtained by solid-state fermentation using citric pulp by Fusarium moniliforme: Influence on Lavandula angustifolia Mill. cultivated in vitro" (PDF). Pakistan Journal of Botany. 45 (6): 2057–2064. Retrieved 26 November 2014.
  2. ^ a b Camara, M. C. et al (2015) General Aspects and Applications of Gibberelins and Gibberellic Acid in Plants. In: Hardy, J.. (Org.). Gibberellins and Gibberellic Acid: Biosynthesis, Regulation and Physiological Effects. 1ed.Hauppauge: Nova Science Publishers, 2015, v., p. 1-21.
  3. ^ a b Riley, John M. "Gibberellic Acid for Fruit Set and Seed Germination". Retrieved 26 Oct 2012.
  4. ^ Edwards, Miriam (1976). "Dormancy in Seeds of Charlock (Sinapis arvensis L.)". Plant Physiol. 58 (5): 626–630. doi:10.1104/pp.58.5.626. PMC 542271. PMID 16659732.