title: Metabolic engineering of isoflavone genistein in Brassica napus with soybean isoflavone synthase.
abstract: Genistein, 4',5,7-trihydroxyisoflavone, is an isoflavonoid compound predominantly restricted to legumes and known to possess phyto-oestrogenic and antioxidative activities. The key enzyme that redirects phenylpropanoid pathway intermediates from flavonoids to isoflavonoids is the isoflavone synthase (IFS). Brassica napus is a non-legume oilseed crop with vegetative tissues producing phenylpropanoids and flavonoids, but does not naturally accumulate isoflavones due to the absence of IFS. To demonstrate whether exogenous IFS is able to use endogenous substrate to produce isoflavone genistein in oilseed crop, the soybean IFS gene (GmIFS2) was incorporated into B. napus plants. The presence of GmIFS2 in B. napus was shown to direct the synthesis and accumulation of genistein derivatives in leaves up to 0.72 mg g(-1) DW. In addition, expression levels for most B. napus genes in the phenylpropanoid pathway were altered. These results suggest that the heterologous GmIFS2 enzyme is functionally active at using the B. napus naringenin as a substrate to produce genistein in oilseed rape.
authors.affiliation: College of Plant Sciences, Jilin University, Changchun, 130062, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Jian-Chun
authors.initials: JC
authors.lastname: Qin
authors.forename: Qing-Yu
authors.initials: QY
authors.lastname: Wang
authors.forename: Xian
authors.initials: X
authors.lastname: Wu
authors.forename: Chen-Yong
authors.initials: CY
authors.lastname: Lang
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Pan
authors.forename: Margaret Y
authors.initials: MY
authors.lastname: Gruber
authors.forename: Ming-Jun
authors.initials: MJ
authors.lastname: Gao
mesh_terms: D029688:Brassica napus / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D019833:Genistein / Q000378:metabolism*; D060847:Metabolic Engineering; D010105:Oxygenases / Q000235:genetics*; D018515:Plant Leaves / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D013025:Glycine max / Q000201:enzymology*; D014170:Transformation, Genetic
chemical_list: D019833:Genistein; D010105:Oxygenases; C048489:isoflavone synthase