INVESTIGADORES
PITTA-ALVAREZ Sandra Irene
artículos
Título:
Long-term culture of hairy roots of Brugmansia candida
Autor/es:
MARCONI PL, SETTEN LM, CÁLCENA EN, ALVAREZ MA AND PITTA-ALVAREZ SI
Revista:
Electronic Journal of Integrative Biosciences
Editorial:
Arkansas State University
Referencias:
Lugar: Arkansas, USA; Año: 2008 vol. 3 p. 38 - 44
Resumen:
Hairy roots cultures, which are the result of infection with Agrobacterium rhizogenes, present a number of advantages over other in vitro cultures. One of the most important ones is the genotypic and phenotypic stability of these cultures over the years. Our group has been working with hairy roots of Brugmansia candida, producer of the tropane alkaloids scopolamine and hyoscyamine, widely used in medicine as anticholinergics. Surprisingly, in our research, which spanned 5 years of culture, we encountered a pronounced increase in the production of scopolamine and a significant decrease in growth. Contradictory results have been found in the literature, where long-term stability as well as modifications in phenotypes after several subcultures were reported. Since these metabolites are involved in defense mechanisms and, in addition, in vitro cultures represent in themselves a stressful situation, it could be hypothesized that the whole biosynthetic pathway could be up-regulated. The limitations to this accumulation could be determined by negative feedback mechanisms or by the incapacity of the roots to tolerate its toxicity. The hairy roots obtained in our laboratory were not engineered to overexpress hyoscyamine-6-â-hydroxydase (H6H), and therefore the changes observed cannot be attributed to higher amounts of this enzyme. However, further studies, particularly at the molecular level, have to be initiated to determine if subculture of the roots affect their genetic stability. Nevertheless, from the cited data, it is clear that stability must be permanently controlled, particularly if long-term industrial processes are entailed.