Abstract
A new auxin response gene in Arabidopsis called AXR3 has been identified. This gene is defined by two semi-dominant mutations which affect many auxin-regulated developmental processes. Auxin has been shown to maintain apical dominance, inhibit root elongation, stimulate adventitious rooting, mediate root gravitropism, and stimulate transcription from the SAUR-AC1 promoter. Mutant axr3 plants show enhanced apical dominance, reduced root elongation, increased adventitious rooting, no root gravitropism, and ectopic expression from the SAUR-AC1 promoter. These phenotypes suggest an increased auxin response in the mutants. In support of this hypothesis, many of the phenotypes are partially restored to wild-type by exogenous cytokinin, a treatment that could restore a more wild-type auxin to cytokinin ratio.
MeSH terms
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2,4-Dichlorophenoxyacetic Acid / pharmacology
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Adenine / analogs & derivatives
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Adenine / pharmacology
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Amino Acids / pharmacology
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Amino Acids, Cyclic*
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Arabidopsis / cytology
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Arabidopsis / drug effects
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Arabidopsis / genetics*
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Arabidopsis / growth & development
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Arabidopsis Proteins*
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Benzyl Compounds
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Cytokinins / pharmacology
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Gene Expression
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Genes, Plant*
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Indoleacetic Acids / pharmacology*
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Kinetin
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Mutation
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Naphthaleneacetic Acids / pharmacology
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Phenotype
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Plant Proteins / genetics*
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Promoter Regions, Genetic*
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Purines
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Transcription, Genetic
Substances
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Amino Acids
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Amino Acids, Cyclic
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Arabidopsis Proteins
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Benzyl Compounds
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Cytokinins
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Indoleacetic Acids
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Naphthaleneacetic Acids
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Plant Proteins
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Purines
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SAUR-AC1 protein, Arabidopsis
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2,4-Dichlorophenoxyacetic Acid
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1-naphthaleneacetic acid
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1-aminocyclopropane-1-carboxylic acid
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indoleacetic acid
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Adenine
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benzylaminopurine
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Kinetin