An overview of gibberellin metabolism enzyme genes and their related mutants in rice.
To enhance our understanding of GA metabolism in rice (Oryza sativa), we intensively screened and identified 29 candidate genes encoding the following GA metabolic enzymes using all available rice DNA databases: ent-copalyl diphosphate synthase (CPS), ent-kaurene synthase (KS), ent-kaurene oxidase (KO), ent-kaurenoic acid oxidase (KAO), GA 20-oxidase (GA20ox), GA 3-oxidase (GA3ox), and GA 2-oxidase (GA2ox). In contrast to the Arabidopsis genome, multiple CPS-like, KS-like, and KO-like genes were identified in the rice genome, most of which are contiguously arranged. We also identified 18 GA-deficient rice mutants at six different loci from rice mutant collections. Based on the mutant and expression analyses, we demonstrated that the enzymes catalyzing the early steps in the GA biosynthetic pathway (i.e. CPS, KS, KO, and KAO) are mainly encoded by single genes, while those for later steps (i.e. GA20ox, GA3ox, and GA2ox) are encoded by gene families. The remaining CPS-like, KS-like, and KO-like genes were likely to be involved in the biosynthesis of diterpene phytoalexins rather than GAs because the expression of two CPS-like and three KS-like genes (OsCPS2, OsCPS4, OsKS4, OsKS7, and OsKS8) were increased by UV irradiation, and four of these genes (OsCPS2, OsCPS4, OsKS4, and OsKS7) were also induced by an elicitor treatment.
Sakamoto
Tomoaki
T
Field Production Science Center, University of Tokyo, Nishi-Tokyo, Tokyo 188-0002, Japan.
Miura
Koutarou
K
Itoh
Hironori
H
Tatsumi
Tomoko
T
Ueguchi-Tanaka
Miyako
M
Ishiyama
Kanako
K
Kobayashi
Masatomo
M
Agrawal
Ganesh K
GK
Takeda
Shin
S
Abe
Kiyomi
K
Miyao
Akio
A
Hirochika
Hirohiko
H
Kitano
Hidemi
H
Ashikari
Motoyuki
M
Matsuoka
Makoto
M
D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D004798:Enzymes / Q000235:genetics* / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D012275:Oryza / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D004798:Enzymes; D005875:Gibberellins; D010940:Plant Proteins; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D010105:Oxygenases; C089210:gibberellin, 2-oxoglutarate-oxygen oxidoreductase (20-hydroxylating, oxidizing); C499575:AtGA2ox7 protein, Arabidopsis; C499576:AtGA2ox8 protein, Arabidopsis; C121463:gibberellin 2-dioxygenase; C066398:ent-kaurene oxidase; C423619:ent-kaurenoic acid oxidase; C108186:gibberellin 3beta-hydroxylase; D019883:Alkyl and Aryl Transferases; C090963:ent-kaurene synthetase A; C105712:ent-kaurene synthetase B