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DOI: 10.1055/s-2007-967199
© Georg Thieme Verlag KG Stuttgart · New York
Enhancement of Cardenolide and Phytosterol Levels by Expression of an N-Terminally Truncated 3-Hydroxy-3-methylglutaryl CoA Reductase in Transgenic Digitalis minor
Publication History
Received: February 14, 2007
Revised: March 28, 2007
Accepted: March 30, 2007
Publication Date:
22 May 2007 (online)
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Abstract
Pathway engineering in medicinal plants attains a special significance in Digitalis species, the main industrial source of cardiac glycosides, steroidal metabolites derived from mevalonic acid via the triterpenoid pathway. In this work, the Arabidopsis thaliana HMG1 cDNA, coding the catalytic domain of 3-hydroxy-3-methylglutaryl CoA reductase (HMGR1S), a key enzyme of the MVA pathway, was expressed in the cardenolide-producing plant Digitalis minor. Transgenic plants were morphologically indistinguishable from control wild plants and displayed the same developmental pattern. Constitutive expression of HMG1 resulted in an increased sterol and cardenolide production in both in vitro- and greenhouse-grown plants. This work demonstrates that transgenic D. minor plants are a valuable system to study and achieve metabolic engineering of the cardenolide pathway and in consequence for the genetic improvement of Digitalis species.
Abbreviations
DMAPP: dimethylallyl diphosphate
HMG-CoA: 3-hydroxy-3-methyl glutaryl coenzyme A
HMGR: 3-hydroxy-3-methylglutaryl-CoA reductase
IPP: isopentenyl diphosphate
MVA: mevalonic acid
PCR: polymerase chain reaction
Key words
Cardenolides - Digitalis minor - Plantaginaceae - isoprenoids - 3-hydroxy-3-methylglutaryl reductase (HMGR) - metabolic engineering - transgenic plants
- Supporting Information for this article is available online at
- Supporting Information .
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Dr. Ester Sales
Dpt. Agricultura y Economía Agraria
Universidad de Zaragoza
Escuela Politécnica Superior
Ctra. Cuarte s/n
22071 Huesca
Spain
Phone: +34-974-239-325
Fax: +34-974-239-302
Email: esalesc@unizar.es
- www.thieme-connect.de/ejournals/toc/plantamedica