Английская Википедия:Gibberellic acid
Gibberellic acid (also called gibberellin A3 or 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] 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.Шаблон: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.Шаблон: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 also
References
- ↑ Шаблон:Cite journal
- ↑ 2,0 2,1 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.
- ↑ 3,0 3,1 Шаблон:Cite web
- ↑ Шаблон:Cite journal
