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.[2] The abnormal roots are particularly easy to culture in artificial media because hormones are not needed in contrast to adventitious roots,[2] 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.[2][3][4]
Some of the applied research on utilization of hairy root cultures has been and is conducted at VTT Technical Research Centre of Finland.[5][6] Other labs working on hairy roots are the phytotechnology lab of Amiens University and the Arkansas Biosciences Institute.
^Ritala, Anneli; Dong, Lemeng; Imseng, Nicole; Seppänen-Laakso, Tuulikki; Vasilev, Nikolay; van der Krol, Sander; Rischer, Heiko; Maaheimo, Hannu; Virkki, Arho; Brändli, Johanna; Schillberg, Stefan; Eibl, Regine; Bouwmeester, Harro; Oksman-Caldentey, Kirsi-Marja (April 2014). "Evaluation of tobacco (Nicotiana tabacum L. cv. Petit Havana SR1) hairy roots for the production of geraniol, the first committed step in terpenoid indole alkaloid pathway". Journal of Biotechnology. 176: 20–28. doi:10.1016/j.jbiotec.2014.01.031. PMID24530945.