Indole-3-butyric acid

Indole-3-butyric acid (1H-indole-3-butanoic acid, IBA) is a white to light-yellow crystalline solid, with the molecular formula C₁₂H₁₃NO₂. It melts at 125°C in atmospheric pressure and decomposes before boiling. IBA is a plant hormone in the auxin family and is an ingredient in many commercial horticultural plant rooting products.

Indole-3-butyric acid

Names
Preferred IUPAC name 4-(1H-Indol-3-yl)butanoic acid
Other names 1H-Indole-3-butanoic acid Indole-3-butyric acid 3-Indolebutyric acid Indolebutyric acid IBA
Identifiers
CAS Number	133-32-4 Y
3D model (JSmol)	Interactive image
Beilstein Reference	171120
ChEBI	CHEBI:33070 Y
ChEMBL	ChEMBL582878 Y
ChemSpider	8298 Y
DrugBank	DB02740 Y
ECHA InfoCard	100.004.638
EC Number	205-101-5
Gmelin Reference	143637
KEGG	C11284 Y
PubChem CID	8617
RTECS number	NL5250000
UNII	061SKE27JP
CompTox Dashboard (EPA)	DTXSID8032623
InChI InChI=1S/C12H13NO2/c14-12(15)7-3-4-9-8-13-11-6-2-1-5-10(9)11/h1-2,5-6,8,13H,3-4,7H2,(H,14,15) Y Key: JTEDVYBZBROSJT-UHFFFAOYSA-N Y InChI=1/C12H13NO2/c14-12(15)7-3-4-9-8-13-11-6-2-1-5-10(9)11/h1-2,5-6,8,13H,3-4,7H2,(H,14,15) Key: JTEDVYBZBROSJT-UHFFFAOYAT
SMILES O=C(O)CCCc1c[nH]c2ccccc12
Properties
Chemical formula	C12H13NO2
Molar mass	203.241 g·mol−1
Appearance	White to light yellow crystals
Density	1.252 g/cm3
Melting point	125 °C (257 °F; 398 K)
Boiling point	Decomposes
Structure
Crystal structure	cubic
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H315, H319, H335
Precautionary statements	P261, P264, P270, P271, P280, P301+P310, P302+P352, P304+P340, P305+P351+P338, P312, P321, P330, P332+P313, P337+P313, P362, P403+P233, P405, P501
Flash point	211.8 °C (413.2 °F; 484.9 K)
Safety data sheet (SDS)	Oxford MSDS
Related compounds
Related	auxin indole-3-acetic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Plant hormone

Since IBA is not completely soluble in water, it is typically dissolved in 75% or purer alcohol for use in plant rooting, making a solution of between 10,000 and 50,000 ppm. This alcohol solution is then diluted with distilled water to the desired concentration. IBA is also available as a salt, which is soluble in water. The solution should be kept in a cool, dark place for best results.

This compound had been thought to be strictly synthetic; however, it was reported that the compound was isolated from leaves and seeds of maize and other species. In maize, IBA has been shown to be biosynthesized in vivo from IAA and other compounds as precursors.^[1] This chemical may also be extracted from any of the Salix (Willow) genus.^[2]

Plant tissue culture

In plant tissue culture IBA and other auxins are used to initiate root formation in vitro in a procedure called micropropagation. Micropropagation of plants is the process of using small samples of plants called explants and causing them to undergo growth of differentiated or undifferentiated cells. In connection with cytokinins like kinetin, auxins like IBA can be used to cause the formation of masses of undifferentiated cells called callus. Callus formation is often used as a first step process in micropropagation where the callus cells are then caused to form other tissues such as roots by exposing them to certain hormones like auxins that produce roots. The process of callus to root formation is called indirect organogenesis whereas if roots are formed from the explant directly it is called direct organogenesis.^[3]

In a study of Camellia sinensis, the effect of three different auxins, IBA, IAA and NAA were examined to determine the relative effect of each auxin on root formation. According to the result for the species, IBA was shown to produce a higher yield of roots compared to the other auxins.^[4] The effect of IBA is in concurrence with other studies where IBA is the most commonly used auxin for root formation.^[5]

Mechanism

Although the exact method of how IBA works is still largely unknown, genetic evidence has been found that suggests that IBA may be converted into IAA through a similar process to β-oxidation of fatty acids. The conversion of IBA to IAA then suggests that IBA works as a storage sink for IAA in plants.^[6] There is other evidence that suggests that IBA is not converted to IAA but acts as an auxin on its own.^[7]

References

1. Ludwig-Müller, J. (2000). "Indole-3-butyric acid in plant growth and development". Plant Growth Regulation. Vol. 32, no. 2–3.
2. William G. Hopkins (1999). Introduction to plant physiology. Wiley. ISBN 978-0-471-19281-7.
3. Bridgen, M.P, Masood, Z.H. and Spencer-Barreto, M. (1992). "A laboratory exercise to demonstrate direct and indirect shoot organogenesis from leaves of Torenia fournieri". HortTechnology. pp. 320–322.{{cite news}}: CS1 maint: multiple names: authors list (link)
4. Rout, G.R. (Feb 2006). "Effect of auxins on adventitious root development from single node cuttings of Camellia sinensis (L.) Kuntze and associated biochemical changes". Plant Growth Regulation. Vol. 48, no. 2.
5. Pooja Goyal; Sumita Kachhwaha; S. L. Kothari (April 2012). "Micropropagation of Pithecellobium dulce (Roxb.) Benth—a multipurpose leguminous tree and assessment of genetic fidelity of micropropagated plants using molecular markers". Physiol Mol Biol Plants. Vol. 18, no. 2.
6. Zolman, B.K., Martinez, N., Millius, A., Adham, A.R., Bartel, B (2008). "Identification and characterization of Arabidopsis indole-3-butyric acid response mutants defective in novel peroxisomal enzymes". Genetics. Vol. 180, no. 1.{{cite news}}: CS1 maint: multiple names: authors list (link)
7. Ludwig-Müller, J. (2000). "Indole-3-butyric acid in plant growth and development". Plant Growth Regulation. Vol. 32, no. 2–3.

External links

Media related to Indolebutyric acid at Wikimedia Commons