title: Development of a novel system for producing ajmalicine and serpentine using direct culture of leaves in Catharanthus roseus intact plant.
abstract: Due to problems of production instability, the production of plant secondary metabolites using dedifferentiated cells (callus) is not always feasible on an industrial scale. To propose a new methodology, which does not use dedifferentiated cells, a novel system for producing useful secondary metabolites using the direct culture of intact plant leaves was developed. Catharanthus roseus was used as a model medicinal plant to produce terpenoid indole alkaloids (TIAs) by suspension culture of the leaves in the phytohormone-free MS liquid medium. Adjustment of the osmotic pressure (993 kPa at 25 degrees C) in the medium, light irradiation (60 micromol m(-2) s(-1)) and addition of glucose (10 g/l) were effective to promote the production of TIAs such as ajmalicine (Aj) and serpentine (Sp). On the basis of semi-quantitative RT-PCR analyses, it was revealed that the culture conditions promoted gene expression of enzymes in the TIA pathway in the cultured leaves. By feeding glucose (10 g/l) on day 10 of the culture period, Aj was produced at a concentration of about 18 mg/l and Sp was produced at a concentration about 11-fold that of the control. These results represent the first step in the development of a novel production system for plant secondary metabolites.
authors.affiliation: Life Science and Bioengineering, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Iwase
authors.forename: Hideki
authors.initials: H
authors.lastname: Aoyagi
authors.forename: Masaru
authors.initials: M
authors.lastname: Ohme-Takagi
authors.forename: Hideo
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D030008:Catharanthus / Q000378:metabolism* / Q000528:radiation effects / Q000648:ultrastructure; D018929:Cell Culture Techniques / Q000379:methods*; D005947:Glucose / Q000378:metabolism*; D008027:Light; D018515:Plant Leaves / Q000378:metabolism* / Q000528:radiation effects / Q000648:ultrastructure; D046948:Secologanin Tryptamine Alkaloids / Q000378:metabolism*
chemical_list: D046948:Secologanin Tryptamine Alkaloids; C005709:raubasine; C009244:serpentine (alkaloid); D005947:Glucose