Analysis of transcripts in methyl jasmonate-treated ginseng hairy roots to identify genes involved in the biosynthesis of ginsenosides and other secondary metabolites.
Methyl jasmonate (MeJA) treatment increases the levels of plant secondary metabolites, including ginsenosides, which are considered to be the main active compounds in ginseng (Panax ginseng C.A. Meyer). To create a ginseng gene resource that contains the genes involved in the biosynthesis of secondary metabolites, including ginsenosides, we generated 3,134 expression sequence tags (ESTs) from MeJA-treated ginseng hairy roots. These ESTs assembled into 370 clusters and 1,680 singletons. Genes yielding highly abundant transcripts were those encoding proteins involved in fatty acid desaturation, the defense response, and the biosynthesis of secondary metabolites. Analysis of the latter group revealed a number of genes that may be involved in the biosynthesis of ginsenosides, namely, oxidosqualene cyclase (OSC), cytochrome P450, and glycosyltransferase. A novel OSC gene was also identified by this analysis. RNA gel blot analysis confirmed that transcription of this OSC gene, along with squalene synthase (SS) and squalene epoxidase (SE) gene transcription, is increased by MeJA treatment. This ginseng EST data set will also provide important information on the genes that are involved in the biosynthesis of other secondary metabolites and the genes that are responsive to MeJA treatment.
Choi
Dong-Woog
DW
Eugentech, 52 Oun-Dong, Yusong, Taejon, 305-333, South Korea. dwchoi63@chonnam.ac.kr
Jung
JongDuk
J
Ha
Young Im
YI
Park
Hyun-Woo
HW
In
Dong Su
DS
Chung
Hwa-Jee
HJ
Liu
Jang Ryol
JR
D000085:Acetates / Q000494:pharmacology*; D001483:Base Sequence; D003517:Cyclopentanes / Q000494:pharmacology*; D018744:DNA, Plant / Q000235:genetics; D017343:Genes, Plant / Q000187:drug effects; D036145:Ginsenosides / Q000096:biosynthesis*; D054883:Oxylipins; D005894:Panax / Q000187:drug effects / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics*; D018749:RNA, Plant / Q000187:drug effects / Q000235:genetics; D014158:Transcription, Genetic
D000085:Acetates; D003517:Cyclopentanes; D018744:DNA, Plant; D036145:Ginsenosides; D054883:Oxylipins; D010940:Plant Proteins; D018749:RNA, Plant; C072239:methyl jasmonate