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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Arabidopsis / genetics
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Arabidopsis / growth & development*
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Arabidopsis Proteins / genetics*
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Arabidopsis Proteins / physiology
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Cell Division
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Conserved Sequence
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Cytochrome P-450 Enzyme System / physiology
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Dual-Specificity Phosphatases / genetics*
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Dual-Specificity Phosphatases / physiology
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Flowers / cytology
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Flowers / growth & development
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Gene Expression Regulation, Plant
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Genes, Recessive
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Indoleacetic Acids / pharmacology
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Microarray Analysis
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Molecular Sequence Data
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Mutation*
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Organ Size / genetics
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Plant Leaves / growth & development
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Pollen / growth & development
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Sequence Homology, Amino Acid
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Signal Transduction / genetics
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Transcription Factors / physiology
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Transcription, Genetic
Substances
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Arabidopsis Proteins
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Indoleacetic Acids
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TCP14 protein, Arabidopsis
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TCP15 protein, Arabidopsis
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Transcription Factors
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indoleacetic acid
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Cytochrome P-450 Enzyme System
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KLUH protein, Arabidopsis
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Dual-Specificity Phosphatases
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IBR5 protein, Arabidopsis