Planta Med 2011; 77(10): 1048-1053
DOI: 10.1055/s-0030-1250744
Biochemistry, Molecular Biology and Biotechnology
Original Papers
© Georg Thieme Verlag KG Stuttgart · New York

Chemotype-dependent Metabolic Response to Methyl Jasmonate Elicitation in Artemisia annua

Wei Wu1 , 2 , Man Yuan1 , 3 , Qing Zhang1 , Yanming Zhu3 , Li Yong3 , Wei Wang1 , Yan Qi1 , Dianjing Guo1
  • 1School of Life Sciences and the State Key Laboratory for Agrobiotechnology, The Chinese University of Hong Kong, HKSAR, China
  • 2Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin, China
  • 3Changchun University of Chinese Medicine, Changchun, China
Further Information

Publication History

received August 11, 2010 revised Nov. 30, 2010

accepted Dec. 21, 2010

Publication Date:
25 January 2011 (online)

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Abstract

Considerable difference in artemisinin and its direct precursors, artemisinic acid and dihydroartemisinic acid, was detected between two chemotypes within the species Artemisia annua (A. annua). These two chemotypes showed differential metabolic response to methyl jasmonate (MeJA) elicitation. Exogenous application of MeJA resulted in an accumulation of dihydroartemisinic acid and artemisinin in Type I plants. In Type II plants, however, artemisinic acid and artemisinin level decreased dramatically under MeJA elicitation. Squalene and other sesquiterpenes, (e.g., caryophyllene, germacrene D), were stimulated by MeJA in both chemotypes. The effect of MeJA elicitation was also studied at the transcription level. Real time RT-PCR analysis showed a coordinated activation of most artemisinin pathway genes by MeJA in Type I plants. The lack of change in cytochrome P450 reductase (CPR) transcript in Type I plants indicates that the rate-limiting enzymes in artemisinin biosynthesis have yet to be identified. Other chemotype-specific electron donor proteins likely exist in A. annua to meet the demand for P450-mediated reactions in MeJA-mediated cellular processes. In Type II plants, mRNA expression patterns of most pathway genes were consistent with the reduced artemisinin level. Intriguingly, the mRNA transcript of aldehyde dehydrogenase1 (ADHL1), an enzyme which catalyzes the oxidation of artemisinic and dihydroartemisinic aldehydes, was upregulated by MeJA. The differential metabolic response to MeJA suggests a chemotype-dependent metabolic flux control towards artemisinin and sterol production in the species A. annua.

References

Dianjing Guo

School of Life Sciences and the State Key Laboratory for Agrobiotechnology
The Chinese University of Hong Kong

HKSAR

China

Phone: +85 2 26 09 62 98

Fax: +85 2 26 03 57 45

Email: djguo@cuhk.edu.hk