title: The Tinkerbell (Tink) Mutation Identifies the Dual-Specificity MAPK Phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) as a Novel Regulator of Organ Size in Arabidopsis.
abstract: Mitogen-activated dual-specificity MAPK phosphatases are important negative regulators in the MAPK signalling pathways responsible for many essential processes in plants. In a screen for mutants with reduced organ size we have identified a mutation in the active site of the dual-specificity MAPK phosphatase indole-3-butyric acid-response5 (IBR5) that we named tinkerbell (tink) due to its small size. Analysis of the tink mutant indicates that IBR5 acts as a novel regulator of organ size that changes the rate of growth in petals and leaves. Organ size and shape regulation by IBR5 acts independently of the KLU growth-regulatory pathway. Microarray analysis of tink/ibr5-6 mutants identified a likely role for this phosphatase in male gametophyte development. We show that IBR5 may influence the size and shape of petals through auxin and TCP growth regulatory pathways.
authors.affiliation: ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Royal Parade, Parkville, Victoria, 3010, Australia.
authors.forename: Kim L
authors.initials: KL
authors.lastname: Johnson
authors.affiliation: Institute for Biochemistry and Biology, University of Potsdam, 14476, Potsdam, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Ramm
authors.affiliation: Institute for Biochemistry and Biology, University of Potsdam, 14476, Potsdam, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kappel
authors.affiliation: Sainsbury Laboratory, Cambridge University, Cambridge, CB2 1LR, United Kingdom.
authors.forename: Sally
authors.initials: S
authors.lastname: Ward
authors.affiliation: Sainsbury Laboratory, Cambridge University, Cambridge, CB2 1LR, United Kingdom.
authors.forename: Ottoline
authors.initials: O
authors.lastname: Leyser
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, 630-0192, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Sakamoto
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, 630-0192, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kurata
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich, NR4 7UH, United Kingdom.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Bevan
authors.affiliation: Institute for Biochemistry and Biology, University of Potsdam, 14476, Potsdam, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lenhard
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology; D002455:Cell Division; D017124:Conserved Sequence; D003577:Cytochrome P-450 Enzyme System / Q000502:physiology; D054637:Dual-Specificity Phosphatases / Q000235:genetics* / Q000502:physiology; D035264:Flowers / Q000166:cytology / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D005808:Genes, Recessive; D007210:Indoleacetic Acids / Q000494:pharmacology; D046228:Microarray Analysis; D008969:Molecular Sequence Data; D009154:Mutation; D009929:Organ Size / Q000235:genetics; D018515:Plant Leaves / Q000254:growth & development; D011058:Pollen / Q000254:growth & development; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000502:physiology; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C581419:TCP14 protein, Arabidopsis; C558187:TCP15 protein, Arabidopsis; D014157:Transcription Factors; C030737:indoleacetic acid; D003577:Cytochrome P-450 Enzyme System; C546334:KLUH protein, Arabidopsis; D054637:Dual-Specificity Phosphatases; C483728:IBR5 protein, Arabidopsis