Gibberellic acid (also called gibberellin A3, GA, and GA₃) is a hormone found in plants and fungi. 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.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. Gibberellic acid is a simple

gibberellin Gibberellins (GAs) are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development, and leaf and fruit senescence. GAs are one of the longest-known classes of plan ...

, a

pentacyclic A cyclic flower is a flower type formed out of a series of whorls; sets of identical organs attached around the axis at the same point. Most flowers consist of a single whorl of sepals termed a calyx; a single whorl of petals termed a corolla; on ...

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. GA stimulates the cells of germinating seeds to produce mRNA molecules that code for

hydrolytic enzymes Hydrolase is a class of enzyme that commonly perform as biochemical catalysts that use water to break a chemical bond, which typically results in dividing a larger molecule into smaller molecules. Some common examples of hydrolase enzymes are este ...

. 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. 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 ''Gibberella fujikuroi'' is a fungal plant pathogen. It causes ''bakanae'' disease in rice seedlings. Another name is foolish seedling disease. It gets that name because the seeds can be infected, leading to disparate outcomes for the plant. Th ...

'' (thus the name), which afflicts rice plants. ''Fujikuroi''-infected plants develop ''

bakanae or bakanae disease (, , ), from the Japanese for "foolish seedling", is a disease that infects the rice plant. It is caused by the fungus ''Gibberella fujikuroi'', the metabolism of which produces a surplus of gibberellic acid. In the plant, this ...

'' ("foolish seedling"), which causes them to rapidly elongate beyond their normal adult height. The plants subsequently

lodge Lodge is originally a term for a relatively small building, often associated with a larger one. Lodge or The Lodge may refer to: Buildings and structures Specific * The Lodge (Australia), the official Canberra residence of the Prime Minist ...

due to lack of support, and die. 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. Gibberellic acid is sometimes used in laboratory and greenhouse settings to trigger

germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...

in seeds that would otherwise remain dormant. 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 The Okanagan ( ), also known as the Okanagan Valley and sometimes as the Okanagan Country, is a region in the Canadian province of British Columbia defined by the basin of Okanagan Lake and the Canadian portion of the Okanagan River. It is part ...

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 Malting is the process of steeping, germinating and drying grain to convert it into malt. The malt is mainly used for brewing or whisky making, but can also be used to make malt vinegar or malt extract. Various grains are used for malting, mos ...

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.

References

{{Authority control Plant hormones Cyclohexenols Tertiary alcohols Lactones Heterocyclic compounds with 5 rings Vinylidene compounds

See also

References