title: Diterpene cyclases responsible for the biosynthesis of phytoalexins, momilactones A, B, and oryzalexins A-F in rice.
abstract: Rice (Oryza sativa L.) produces diterpene phytoalexins, such as momilactones, oryzalexins, and phytocassanes. Using rice genome information and in vitro assay with recombinant enzymes, we identified genes (OsKS4 and OsKS10) encoding the type-A diterpene cyclases 9beta-pimara-7,15-diene synthase and ent-sandaracopimaradiene synthase which are involved in the biosynthesis of momilactones A, B and oryzalexins A-F respectively. Transcript levels of these two genes increased remarkably after ultraviolet (UV) treatment, which is consistent with elevated production of phytoalexins by UV. These two genes might prove powerful tools for understanding plant defense mechanisms in rice.
authors.affiliation: Department of Bioresource Engineering, Yamagata University, Tsuruoka, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Otomo
authors.forename: Yuri
authors.initials: Y
authors.lastname: Kanno
authors.forename: Akihiro
authors.initials: A
authors.lastname: Motegi
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Kenmoku
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Yamane
authors.forename: Wataru
authors.initials: W
authors.lastname: Mitsuhashi
authors.forename: Hideaki
authors.initials: H
authors.lastname: Oikawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Toshima
authors.forename: Hironori
authors.initials: H
authors.lastname: Itoh
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsuoka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sassa
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Toyomasu
mesh_terms: D004224:Diterpenes / Q000378:metabolism*; D004798:Enzymes / Q000235:genetics*; D017343:Genes, Plant; D007783:Lactones; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D010936:Plant Extracts / Q000096:biosynthesis; D018749:RNA, Plant / Q000032:analysis / Q000528:radiation effects; D012717:Sesquiterpenes; D013729:Terpenes; D014466:Ultraviolet Rays; D000094162:Phytoalexins
chemical_list: D004224:Diterpenes; D004798:Enzymes; D007783:Lactones; D010936:Plant Extracts; D018749:RNA, Plant; D012717:Sesquiterpenes; D013729:Terpenes; C477203:momilactone B; C116023:momilactone A; D000094162:Phytoalexins