title: YCZ-18 is a new brassinosteroid biosynthesis inhibitor.
abstract: Plant hormone brassinosteroids (BRs) are a group of polyhydroxylated steroids that play critical roles in regulating broad aspects of plant growth and development. The structural diversity of BRs is generated by the action of several groups of P450s. Brassinazole is a specific inhibitor of C-22 hydroxylase (CYP90B1) in BR biosynthesis, and the application use of brassinazole has emerged as an effective way of complementing BR-deficient mutants to elucidate the functions of BRs. In this article, we report a new triazole-type BR biosynthesis inhibitor, YCZ-18. Quantitative analysis the endogenous levels of BRs in Arabidopsis indicated that YCZ-18 significantly decreased the BR contents in plant tissues. Assessment of the binding affinity of YCZ-18to purified recombinant CYP90D1 indicated that YCZ-18 induced a typical type II binding spectrum with a Kd value of approximately 0.79 μM. Analysis of the mechanisms underlying the dwarf phenotype associated with YCZ-18 treatment of Arabidopsis indicated that the chemically induced dwarf phenotype was caused by a failure of cell elongation. Moreover, dissecting the effect of YCZ-18 on the induction or down regulation of genes responsive to BRs indicated that YCZ-18 regulated the expression of genes responsible for BRs deficiency in Arabidopsis. These findings indicate that YCZ-18 is a potent BR biosynthesis inhibitor and has a new target site, C23-hydroxylation in BR biosynthesis. Application of YCZ-18 will be a good starting point for further elucidation of the detailed mechanism of BR biosynthesis and its regulation.
authors: Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo Nakano, Akita, Japan.
authors: Keimei
authors: K
authors: Oh
authors: Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo Nakano, Akita, Japan.
authors: Tadashi
authors: T
authors: Matsumoto
authors: Antibiotics laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan.
authors: Ayumi
authors: A
authors: Yamagami
authors: Department of Bioproduction, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo Nakano, Akita, Japan.
authors: Atushi
authors: A
authors: Ogawa
authors: Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo Nakano, Akita, Japan.
authors: Kazuhiro
authors: K
authors: Yamada
authors: Department of Bioproduction, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo Nakano, Akita, Japan.
authors: Ryuichiro
authors: R
authors: Suzuki
authors: Biotechnology Research Center, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo Nakano, Akita, Japan.
authors: Takayuki
authors: T
authors: Sawada
authors: Antibiotics laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan; RIKEN Center for Sustainable Resource Science, Wako, Saitama, Japan.
authors: Shozo
authors: S
authors: Fujioka
authors: Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, Shimoshinjo Nakano, Akita, Japan.
authors: Yuko
authors: Y
authors: Yoshizawa
authors: Antibiotics laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan; RIKEN Center for Sustainable Resource Science, Wako, Saitama, Japan; CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan.
authors: Takeshi
authors: T
authors: Nakano
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000187:drug effects*; D060406:Brassinosteroids / Q000096:biosynthesis*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004149:Dioxoles / Q000737:chemistry / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D010641:Phenotype; D011485:Protein Binding; D014230:Triazoles / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D004149:Dioxoles; D014230:Triazoles; C000604930:YCZ-18; D003577:Cytochrome P-450 Enzyme System; C500774:cytochrome P-450 90D1, Arabidopsis