Hairy root culture
Hairy root culture, also called transformed root culture, is a type of plant tissue culture that is used to study plant metabolic processes or to produce valuable secondary metabolites or recombinant proteins, often with plant genetic engineering.
A naturally occurring soil bacterium Agrobacterium rhizogenes that contains root inducing plasmids (also called Ri plasmids) can infect plant roots and cause them to produce a food source for the bacterium, opines, and to grow abnormally. The abnormal roots are particularly easy to culture in artificial media because hormones are not needed, and they are neoplastic, with indefinite growth. The neoplastic roots produced by A. rhizogenes infection have a high growth rate (compared to untransformed adventitious roots), as well as genetic and biochemical stability.
Currently the main constraint for commercial utilization of hairy root culture is the development and up-scaling of appropriate (bioreactors) vessels for the delicate and sensitive hairy roots. 
So far, the only company based on Non GMO Hairy root Cultures as an industrial level is a Swiss company called ROOTec bioactives AG in Witterswil (SO). There also is a French company called Root Lines Technology SAS which uses Genetically Modified Hairy root cultures.
Further applications include detailed studies of fundamental molecular, genetic and biochemical aspects of genetic transformation and of hairy root induction.
Genetically transformed cultures
The Ri plasmids can be engineered to also contain T-DNA, used for genetic transformation (biotransformation) of the plant cells. The resulting genetically transformed root cultures can produce high levels of secondary metabolites, comparable or even higher than those of intact plants.
Use in plant propagation
|This section requires expansion. (August 2010)|
- Shanks JV, Morgan J (April 1999). "Plant 'hairy root' culture". Curr. Opin. Biotechnol. 10 (2): 151–5. doi:10.1016/S0958-1669(99)80026-3. PMID 10209145.
- Guillon S, Tremouillaux-Guiller J, Pati PK, Rideau M, Gantet P (2006) Hairy root research: recent scenario and exciting prospects. Curr Opin Plant Biol 9:341-346. Missing or empty
- Georgiev M, Ludwig-Müller J, Bley Th (2010). "Hairy root culture: Copying Nature in New Bioprocesses (chapter 10)". In R Arora (ed.). Medicinal Plant Biotechnology. Delhi: The Institute of Nuclear Medicine and Applied Sciences. ISBN 978-1-84593-678-5.
- Georgiev M, Pavlov A, Bley Th (2007). "Hairy root type plant in vitro systems as sources of bioactive substances". Appl. Microbiol. Biotechnol. 74 (6): 1175–1185. doi:10.1007/s00253-007-0856-5. PMID 17294182.
- Crown gall, a plant disease with similar uses caused by a related bacterium, Agrobacterium tumefaciens