title: The auxin response factor, OsARF19, controls rice leaf angles through positively regulating OsGH3-5 and OsBRI1.
abstract: Auxin and brassinosteroid (BR) are important phytohormones for controlling lamina inclination implicated in plant architecture and grain yield. But the molecular mechanism of auxin and BR crosstalk for regulating lamina inclination remains unknown. Auxin response factors (ARFs) control various aspects of plant growth and development. We here report that OsARF19-overexpression rice lines show an enlarged lamina inclination due to increase of its adaxial cell division. OsARF19 is expressed in various organs including lamina joint and strongly induced by auxin and BR. Chromatin immunoprecipitation (ChIP) and yeast one-hybrid assays demonstrate that OsARF19 binds to the promoter of OsGH3-5 and brassinosteroid insensitive 1 (OsBRI1) directing their expression. OsGH3-5-overexpression lines show a similar phenotype as OsARF19-O1. Free auxin contents in the lamina joint of OsGH3-5-O1 or OsARF19-O1 are reduced. OsGH3-5 is localized at the endoplasmic retieulum (ER) matching reduction of the free auxin contents in OsGH3-5-O1. osarf19-TDNA and osgh3-5-Tos17 mutants without erected leaves show a function redundancy with other members of their gene family. OsARF19-overexpression lines are sensitive to exogenous BR treatment and alter the expressions of genes related to BR signalling. These findings provide novel insights into auxin and BR signalling, and might have significant implications for improving plant architecture of monocot crops.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
authors.forename: SaiNa
authors.initials: S
authors.lastname: Zhang
authors.forename: SuiKang
authors.initials: S
authors.lastname: Wang
authors.forename: YanXia
authors.initials: Y
authors.lastname: Xu
authors.forename: ChenLiang
authors.initials: C
authors.lastname: Yu
authors.forename: ChenJia
authors.initials: C
authors.lastname: Shen
authors.forename: Qian
authors.initials: Q
authors.lastname: Qian
authors.forename: Markus
authors.initials: M
authors.lastname: Geisler
authors.forename: De An
authors.initials: de A
authors.lastname: Jiang
authors.forename: YanHua
authors.initials: Y
authors.lastname: Qi
mesh_terms: D001483:Base Sequence; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D007210:Indoleacetic Acids / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology; D010641:Phenotype; D010937:Plant Growth Regulators / Q000378:metabolism*; D018515:Plant Leaves / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D036226:Seedlings
chemical_list: D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; C519615:BRI1 protein, Oryza sativa; D017346:Protein Serine-Threonine Kinases
keywords: OsARF19; OsBRI1; rice (Oryza sativa L.)