Diterpene cyclases responsible for the biosynthesis of phytoalexins, momilactones A, B, and oryzalexins A-F in rice.
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.
Otomo
Kazuko
K
Department of Bioresource Engineering, Yamagata University, Tsuruoka, Japan.
Kanno
Yuri
Y
Motegi
Akihiro
A
Kenmoku
Hiromichi
H
Yamane
Hisakazu
H
Mitsuhashi
Wataru
W
Oikawa
Hideaki
H
Toshima
Hiroaki
H
Itoh
Hironori
H
Matsuoka
Makoto
M
Sassa
Takeshi
T
Toyomasu
Tomonobu
T
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
D004224:Diterpenes; D004798:Enzymes; D007783:Lactones; D010936:Plant Extracts; D018749:RNA, Plant; D012717:Sesquiterpenes; D013729:Terpenes; C477203:momilactone B; C116023:momilactone A; D000094162:Phytoalexins