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Author Canel, Camilo ♦ Lopes Cardoso, M. Inês ♦ Whitmer, Serap ♦ van der Fits, Leslie ♦ Pasquali, Giancarlo ♦ van der Heijden, Robert ♦ Hoge, J. Harry C. ♦ Verpoorte, Robert
Source SpringerLink
Content type Text
Publisher Springer-Verlag
File Format PDF
Copyright Year ©1998
Language English
Subject Domain (in DDC) Social sciences ♦ Sociology & anthropology
Abstract Cells of Catharanthus roseus (L.) G. Don were genetically engineered to over-express the enzymes strictosidine synthase (STR; EC 4.3.3.2) and tryptophan decarboxylase (TDC; EC 4.1.1.28), which catalyze key steps in the biosynthesis of terpenoid indole alkaloids (TIAs). The cultures established after Agrobacterium-mediated transformation showed wide phenotypic diversity, reflecting the complexity of the biosynthetic pathway. Cultures transgenic for Str consistently showed tenfold higher STR activity than wild-type cultures, which favored biosynthetic activity through the pathway. Two such lines accumulated over 200 mg · L−1 of the glucoalkaloid strictosidine and/or strictosidine-derived TIAs, including ajmalicine, catharanthine, serpentine, and tabersonine, while maintaining wild-type levels of TDC activity. Alkaloid accumulation by highly productive transgenic lines showed considerable instability and was strongly influenced by culture conditions, such as the hormonal composition of the medium and the availability of precursors. High transgene-encoded TDC activity was not only unnecessary for increased productivity, but also detrimental to the normal growth of the cultures. In contrast, high STR activity was tolerated by the cultures and appeared to be necessary, albeit not sufficient, to sustain high rates of alkaloid biosynthesis. We conclude that constitutive over-expression of Str is highly desirable for increased TIA production. However, given its complexity, limited intervention in the TIA pathway will yield positive results only in the presence of a favorable epigenetic environment.
ISSN 00320935
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1998-05-22
Publisher Place Berlin/Heidelberg
e-ISSN 14322048
Journal Planta
Volume Number 205
Issue Number 3
Page Count 6
Starting Page 414
Ending Page 419


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Source: SpringerLink