Gibberellic acid
This article needs additional citations for verification. (November 2012) |
Names | |
---|---|
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
| |
Identifiers | |
3D model (JSmol)
|
|
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.000.911 |
EC Number |
|
KEGG | |
PubChem CID
|
|
UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
Properties | |
C19H22O6 | |
Molar mass | 346.37 g/mol |
Melting point | 233 to 235 °C (451 to 455 °F; 506 to 508 K) (decomposition) |
5 g/l (20 °C) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
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.
Plants in their normal state produce large amounts of GA3. It is possible to produce the hormone industrially using microorganisms.[2] Nowadays, it is produced by submerse fermentation, but this process presented low yield with high production costs and hence higher sale value. One alternative process to reduce costs of the GA3 production is Solid-State Fermentation (SSF) that allows the use of agro-industrial residues.[1] 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. A unitary mechanism or common rate limiting step controls the response of the enzymes to GA. Increases in ?-amylase and protease activities induced by GA are strictly parallel, with regard to time course of induction and response to GA concentration, to inhibitors of protein and RNA synthesis and to GA antagonists2.The primary site of hormone action is not known, although circumstantial evidence suggests that transcription of the enzyme's structural gene is controlled by GA3; experiments with inhibitors show that RNA synthesis is essential for the hormone to elicit a response. We have attempted to characterize further the mechanism of action of GA, to define more precisely the site of action of the hormone, and to identify some of the components involved in the response of the aleurone tissue.The level of a given enzymatic activity in a eukaryotic cell is generally determined by the number of structural gene copies encoding for that enzyme in the genome of the cell4-8. There is often a simple dose relationship between the number of structural genes and the quantity of encoded protein. 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.
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 grow so much taller than normal that they die from no longer being sturdy enough to support their own weight.[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 rate.[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 bundles and bigger grapes, especially Thompson seedless grapes. In the Okanagan and Creston valleys, it is also used as a growth replicator in the cherry industry. It is used on Clementine Mandarin oranges, which may otherwise cross-pollinate with other citrus and grow undesirable seeds. Applied directly on the blossoms as a spray, it allows for Clementines to produce a full crop of fruit without seeds.
See also
References
- ^ a b 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.
- ^ 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.
- ^ a b Riley, John M. "Gibberellic Acid for Fruit Set and Seed Germination". Retrieved 26 Oct 2012.
- ^ Edwards, Miriam (1976). "Dormancy in Seeds of Charlock (Sinapis arvensis L.)" (PDF). Plant Physiol. 58: 626–630. Retrieved 10 November 2017.