Reference "An overview of gibberellin metabolism enzyme genes and their related mutants in rice"

Reference ID

11073

Title

An overview of gibberellin metabolism enzyme genes and their related mutants in rice

Source

Plant physiology, 2004, vol. 134, pp. 1642-1653

Authors (15)

Sakamoto-T	Miura-K	Itoh-H	Tatsumi-T
Ueguchi-Tanaka-M	Ishiyama-K	Kobayashi-M	Agrawal-G-K
Takeda-S	Abe-K	Miyao-A	Hirochika-H
Kitano-H	Ashikari-M	Matsuoka-M

Abstract

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.