Gibberellic acid

Structural formula
General
Surname	Gibberellic acid
other names	Gibberellin A 3 GIBBERELLIC ACID ( INCI )
Molecular formula	C 19 H 22 O 6
Brief description	colorless crystals
External identifiers / databases
CAS number 77-06-5 EC number 201-001-0 ECHA InfoCard 100,000,911 PubChem 6466 ChemSpider 6223 DrugBank DB07814 Wikidata Q411138
properties
Molar mass	346.38 g mol −1
Physical state	firmly
density	1.34 g cm −3 (20 ° C)
Melting point	223–225 ° C (decomposition)
pK s value	4.0
solubility	poor in water (5 g l −1 at 25 ° C) good in ethanol (125 g l −1 at 25 ° C)
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 319 P: 305 + 351 + 338
Toxicological data	6300 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Gibberellic acid ( GA or GA ₃ ) is a plant phytohormone and the best-known representative from the group of gibberellins . It is a diterpenoid - carboxylic acid .

discovery

Gibberellic acid was discovered in 1954 by BE Cross. It differed from the gibberellins (GA ₁ and GA ₂ ) known since the 1930s in that it was more effective.

Functions

Gibberellic acid promotes the ability and speed of germination , has an influence on the growth in length and the fertilization of the vascular plants and prevents winter dormancy . In higher concentrations, GA influenced protonema of mosses to gravitropism and linear growth. As shown in Physcomitrella patens , individual members of the GA signal line can be found in these plants. Gibberellic acid is produced in the plastids of young leaves and - to promote ripening - in unripe seeds and fruits.

use

In viticulture , GA is applied to the vines to prevent vinegar rot and Botrytis cinerea . In horticulture, it is used as a germination aid in order to trigger the immediate germination of difficult or cold germinating plants.

In fruit growing , GA serves to improve the fruit set in pears, blueberries and lingonberries (10–50 ppm) and to promote smooth skin in apples (50–100 ppm).

When malting , the dormancy of the brewing barley can be broken by adding GA . This process is not permitted in Germany.

In biochemistry , giberellic acid is used in the chemically induced dimerization of certain fusion proteins .

By treating the seeds with gibberellic acid, the dormancy of plant seeds can be shortened.

Admission

In Germany, Austria and Switzerland, plant protection products with gibberellin A _{3 are} approved as an active ingredient.

Individual evidence

1. ↑ Entry on GIBBERELLIC ACID in the CosIng database of the EU Commission, accessed on May 18, 2020.
2. ↑ ^{a b} entry on gibberellic acid. In: Römpp Online . Georg Thieme Verlag, accessed on May 1, 2014.
3. ↑ ^{a b c} data sheet gibberellic acid (PDF) from Merck , accessed on June 1, 2010.
4. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Dissociation Constants of Organic Acids and Bases, pp. 8-51.
5. ↑ ^{a b} data sheet Gibberellic acid from Sigma-Aldrich , accessed on April 3, 2011 ( PDF ).
6. ↑ Entry on gibberellic acid in the ChemIDplus database of the United States National Library of Medicine (NLM) .
7. ↑ Ilse Jahn (Ed.): History of Biology . 3rd edition, Nikol special edition, Hamburg 2004, p. 525.
8. ↑ Filip Vandenbussche, Ana C. Fierro, Gertrud Wiedemann, Ralf Reski , Dominique Van der Straeten: Evolutionary conservation of plant gibberellin signaling pathway components. In: BMC Plant Biology. Volume 7, 2007, p. 65. doi: 10.1186 / 1471-2229-7-65 .
9. ↑ Lucas' Instructions for Fruit Growing, 31st edition 1992, p. 206.
10. ↑ The technology of malt preparation. (PDF) In: Abriss der Bierbrauerei, 8th edition. Ludwig Narziss, Werner Back, Martina Gastl and Martin Zarnkow. WILEY-VCH Verlag, p. 13 , accessed on October 26, 2017 . 
11. ^ Peter Sitte , Hubert Ziegler , Friedrich Ehrendorfer , Andreas Bresinsky : Textbook of botany for universities. Founded by Eduard Strasburger , Fritz Noll, Heinrich Schenck, AF Wilhelm Schimper. 33rd edition. Gustav Fischer, Stuttgart / Jena / New York 1991, ISBN 3-437-20447-5 , p. 390.
12. ↑ General Directorate Health and Food Safety of the European Commission: Entry on Gibberellic acid in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on March 12, 2016.