Chemotype-dependent metabolic response to methyl jasmonate elicitation in Artemisia annua.
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.
School of Life Sciences and State Key Laboratory for Agrobiotechnology, The Chinese University of Hong Kong, HKSAR, China.
Wei
W
Wu
Man
M
Yuan
Qing
Q
Zhang
Yanming
Y
Zhu
Li
L
Yong
Wei
W
Wang
Yan
Y
Qi
Dianjing
D
Guo
D000085:Acetates / Q000494:pharmacology*; D000080924:Aldehyde Dehydrogenase 1 Family; D019883:Alkyl and Aryl Transferases / Q000235:genetics; D031172:Artemisia annua / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D037621:Artemisinins / Q000737:chemistry / Q000378:metabolism; D003517:Cyclopentanes / Q000494:pharmacology*; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D008401:Gas Chromatography-Mass Spectrometry; D018506:Gene Expression Regulation, Plant; D007527:Isoenzymes / Q000235:genetics; D009251:NADPH-Ferrihemoprotein Reductase / Q000235:genetics; D010088:Oxidoreductases / Q000235:genetics; D054883:Oxylipins / Q000494:pharmacology*; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D010940:Plant Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D000081223:Polycyclic Sesquiterpenes; D012333:RNA, Messenger; D050697:Retinal Dehydrogenase / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012717:Sesquiterpenes / Q000737:chemistry / Q000378:metabolism; D045788:Sesquiterpenes, Germacrane / Q000378:metabolism; D013185:Squalene / Q000378:metabolism; D013729:Terpenes / Q000737:chemistry / Q000378:metabolism*
D000085:Acetates; D037621:Artemisinins; D003517:Cyclopentanes; D007527:Isoenzymes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D000081223:Polycyclic Sesquiterpenes; D012333:RNA, Messenger; D012717:Sesquiterpenes; D045788:Sesquiterpenes, Germacrane; D013729:Terpenes; C520462:dihydroartemisinic acid; C047721:artemisic acid; D013185:Squalene; C072239:methyl jasmonate; D003577:Cytochrome P-450 Enzyme System; C031327:artemisinin; C024714:caryophyllene; D010088:Oxidoreductases; C531287:artemisinic aldehyde delta11(13) reductase, Artemisia annua; D000080924:Aldehyde Dehydrogenase 1 Family; D050697:Retinal Dehydrogenase; D009251:NADPH-Ferrihemoprotein Reductase; D019883:Alkyl and Aryl Transferases; C403714:amorpha-4,11-diene synthase; C027259:germacrene D