title: Identification of the protopanaxatriol synthase gene CYP6H for ginsenoside biosynthesis in Panax quinquefolius.
abstract: Panax quinquefolius is one of perennial herbs and well known for its outstanding pharmacological activity. Ginsenosides are thought to be the main active ingredients in P. quinquefolius and exist in many kinds of plant genus Panax (ginseng). Protopanaxatriol synthase, which is considered cytochrome P450 (CYP450) in ginsenoside biosynthesis pathway can convert protopanaxadiol into protopanaxatriol. However, the protopanaxatriol synthase gene in P. quinquefolius has not been identified. Here, we cloned and identified a protopanaxatriol synthase gene from P. quinquefolius (CYP6H, GenBank accession no. KC190491) at the first time, reverse transcription-PCR (RT-PCR) analysis showed no obvious transcription change of CYP6H in methyl jasmonate (MeJA)-induced hairy roots. Ectopic expression of CYP6H in Saccharomyces cerevisiae resulted in the production of protopanaxatriol with added exogenous protopanaxadiol and confirmed by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC/APCIMS). Moreover, high-performance liquid chromatography (HPLC) analysis shows that RNA interferences of CYP6H in transgenic hairy roots could increase the accumulation of protopanaxadiol-type ginsenosides and decrease the accumulation of protopanaxatriol-type ginsenosides, whereas the effect of overexpression CYP6H in transgenic hairy roots was contrary. Our study indicated that CYP6H is a gene encoding protopanaxadiol 6-hydroxylase which could convert protopanaxadiol into protopanaxatriol in P. quinquefolius ginsenoside biosynthesis, we also have confirmed the function of CYP6H on effect accumulation of ginsenosides.
authors: School of Biological and Agricultural Engineering, Jilin University, No. 5988 Renmin Street Nanguan District, Changchun, People's Republic of China.
authors: Le
authors: L
authors: Wang
authors: Shou-Jing
authors: SJ
authors: Zhao
authors: Yan-Long
authors: YL
authors: Liang
authors: Yao
authors: Y
authors: Sun
authors: Hao-Jie
authors: HJ
authors: Cao
authors: Ying
authors: Y
authors: Han
mesh_terms: D000595:Amino Acid Sequence; D001189:Aryl Hydrocarbon Hydroxylases / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D036145:Ginsenosides / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D005894:Panax / Q000201:enzymology / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics*; D012441:Saccharomyces cerevisiae; D012502:Sapogenins / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D036145:Ginsenosides; D010940:Plant Proteins; D012502:Sapogenins; D001189:Aryl Hydrocarbon Hydroxylases; C062916:protopanaxadiol