An Overview of Gibberellin Metabolism Enzyme Genes and Their Related Mutants in Rice

作者：Tomoaki Sakamoto, Koutarou Miura, Hironori Itoh, Tomoko Tatsumi, Miyako Ueguchi‐Tanaka, Kanako Ishiyama, Masatomo Kobayashi, Ganesh Kumar Agrawal, Shin Takeda, K. Abe, Akio Miyao, Hirohiko Hirochika, Hidemi Kitano, Motoyuki Ashikari, Makoto Matsuoka · 发表于：PLANT PHYSIOLOGY · 年份：2004 · DOI：10.1104/pp.103.033696 · 被引用次数：763 · 研究领域：Plant biochemistry and biosynthesis、Plant Gene Expression Analysis、Photosynthetic Processes and Mechanisms

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.