Induction and growth of hairy roots for the production of medicinal compounds

Journal électronique.International audienceThe development of genetically transformed plant tissue cultures and mainly of roots transformed by Agrobacterium rhizogenes (hairy roots), is a key step in the use of in vitro cultures for the production of secondary metabolites. Hairy roots are able to grow fast without phytohormones, and to produce the metabolites of the mother plant. The conditions of transformation (nature and age of the explants, bacterial strain, bacterial density, and the protocol of infection) deeply influence the frequency of the transformation events as well as the growth and productivity of the hairy roots. Then optimization of the culture parameters (medium constituents, elicitation by biotic or abiotic stress) may enhance the capability of the hairy roots to grow fast and to produce valuable compounds.and Newman, 2005). Huperzine A and galantamine (galanthamine) acting as acetylcholinesterase inhibitors have been approved for the treatment of Alzheimer's disease and other neurodegenerative pathologies (Raves et al., 1997; Scott and Goa, 2000). The obtention of medicinal compounds from extraction of wild or cultivated plants can be limited by various problems: plants difficult to cultivate, risk of extinction for over exploited plants, and geopolitical problems, among other causes (Verpoorte et al., 2002). To try to overcome these problems, many attempts were made during the last decades to evaluate the possibility of producing medicinal compounds by in vitro plant cell and organ cultures (Berlin, 1986; Alfermann and Petersen 1995). However, in mos