Plant Cell Reports

, Volume 30, Issue 10, pp 1919–1928

Over-expression of HMG-CoA reductase and amorpha-4,11-diene synthase genes in Artemisia annua L. and its influence on artemisinin content

Original Paper

DOI: 10.1007/s00299-011-1099-6

Cite this article as:
Alam, P. & Abdin, M.Z. Plant Cell Rep (2011) 30: 1919. doi:10.1007/s00299-011-1099-6

Abstract

Artemisinin, an endoperoxide sesquiterpene lactone, is a novel antimalarial natural product isolated from Artemisia annua L. plants. The low concentrations (0.01–1.1%) of this compound in A. annua L. plants is, however, a major constraint for commercialization of artemisinin-based combination therapies (ACTs) recommended by WHO for treating malaria caused by multidrug-resistant P. falciparum sp. In this context, in vivo yield improvement programs were undertaken by us. In the present study, HMG-Co A reductase gene (hmgr) from Catharanthusroseus (L) G. Don and amorpha-4,11-diene synthase (ads) gene from A. annua L. were over-expressed in A. annua L. plants to study their effects on artemisinin yields. The transgenic lines developed from putative transgenic regenerants were evaluated for integration and copy number of the transgenes using hptII gene probe, as it was a part of the expression cassette. The transgenic lines showed positive bands of hptII gene on Southern blots confirming the integration of transgenes. Some of the transgenic lines had single copy of the transgenes, while others had multiple copies. The expressions of hmgr and ads at the transcriptional level were also confirmed in each transgenic line employing RT-PCR assays. The HPLC analyses showed that the artemisinin contents were significantly increased in these transgenics. One of the transgenic lines, TR4, was found to contain 7.65-fold higher (1.73 mg/gDW) artemisinin than the non-transgenic plant (W). The increased artemisinin levels were found to be correlated with HMG-Co A reductase and amorpha-4,11-diene synthase enzymatic activities in the biochemical analyses.

Keywords

Artemisia annua L. hmgr ads Artemisinin Catharanthus roseus Over-expression 

Abbreviations

ACT

Artemisinin-based combination therapy

ADS

Amorpha-4,11-diene synthase enzyme

ads

Amorpha-4,11-diene synthase gene

BAP

Benzene amino purine

CTAB

Cetyl trimethylammonium bromide

HMGR

Hydroxy methyl glutaryl coenzyme A reductase

hmgr

Hydroxy methyl glutaryl coenzyme A gene

HPLC

High performance liquid chromatography

MS

Murashige and Skoog

MVA

Mevalonic acid

NAA

Naphthalene acetic acid

NOS

Nopaline opine synthase

hptII

Hygromycin phosphotransferase gene

RT-PCR

Reverse transcriptase polymerase chain reaction

SIM

Shoot-induction medium

SISM

Shoot-induction selection medium

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  1. 1.Centre for Transgenic Plant Development, Department of Biotechnology, Faculty of ScienceJamia HamdardNew DelhiIndia

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