title: Metabolic engineering of lignan biosynthesis in Forsythia cell culture.
abstract: Lignans are a large class of secondary metabolites in plants, with numerous biological effects in mammals, including antitumor and antioxidant activities. Sesamin, the most abundant furofuran-class lignan in sesame seeds (Sesamum plants), is produced by the cytochrome P450 enzyme CYP81Q1 from the precursor lignan, pinoresinol. In contrast, Forsythia plants produce dibenzylbutyrolactone-class lignans, such as matairesinol, from pinoresinol via the catalysis of pinoresinol/lariciresinol reductase (PLR) and secoisolariciresinol dehydrogenase. Here we present the engineering of lignan biosynthesis in Forsythia cell suspension cultures for the development of an efficient production method of beneficial lignans. A suspension cell culture prepared from leaves of Forsythia koreana produced lignans, mainly pinoresinol and matairesinol glucosides, at levels comparable with that obtained from the leaves. In an attempt to increase the pinoresinol content in Forsythia, we generated a transgenic cell line overexpressing an RNA interference (RNAi) construct of PLR (PLR-RNAi). Down-regulation of PLR expression led to a complete loss of matairesinol and an accumulation of approximately 20-fold pinoresinol in its glucoside form in comparison with the non-transformant. Moreover, the Forsythia transgenic cells co-expressing CYP81Q1 and PLR-RNAi exhibited production of sesamin as well as accumulation of pinoresinol glucoside. These data suggest Forsythia cell suspension to be a promising tool for the engineering of lignan production. To the best of our knowledge, this is the first report on transgenic production of an exogenous lignan in a plant species.
authors.affiliation: Suntory Institute for Bioorganic Research, 1-1-1 Wakayamadai, Shimamoto, Mishima, Osaka, 618-8503, Japan.
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Ono
authors.forename: Kinuyo
authors.initials: K
authors.lastname: Morimoto
authors.forename: Tohru
authors.initials: T
authors.lastname: Yamagaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okazawa
authors.forename: Akio
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Honoo
authors.initials: H
authors.lastname: Satake
mesh_terms: D018929:Cell Culture Techniques; D002478:Cells, Cultured; D004149:Dioxoles; D031657:Forsythia / Q000235:genetics / Q000378:metabolism*; D005663:Furans; D018506:Gene Expression Regulation, Plant; D005818:Genetic Engineering / Q000379:methods*; D017705:Lignans / Q000096:biosynthesis*; D015394:Molecular Structure; D018515:Plant Leaves / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D014170:Transformation, Genetic
chemical_list: D004149:Dioxoles; D005663:Furans; D017705:Lignans; C068935:matairesinol; C054125:sesamin; C103298:pinoresinol