Abstract
The Arabidopsis embryonic root meristem is initiated by the specification of a single cell, the hypophysis. This event critically requires the antagonistic auxin response regulators MONOPTEROS and BODENLOS, but their mechanism of action is unknown. We show that these proteins interact and transiently act in a small subdomain of the proembryo adjacent to the future hypophysis. Here they promote transport of auxin, which then elicits a second response in the hypophysis itself. Our results suggest that hypophysis specification is not the direct result of a primary auxin response but rather depends on cell-to-cell signaling triggered by auxin in adjacent cells.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Arabidopsis / embryology*
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Arabidopsis / genetics
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Arabidopsis / metabolism*
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Arabidopsis Proteins / genetics
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Arabidopsis Proteins / metabolism
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Biological Transport, Active
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism
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Gene Expression Regulation, Developmental
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Gene Expression Regulation, Plant
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Genes, Plant
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Indoleacetic Acids / metabolism*
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Meristem / cytology
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Meristem / embryology
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Meristem / metabolism
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Models, Biological
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Mutation
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Plant Roots / embryology
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Plant Roots / metabolism
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Plants, Genetically Modified
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Signal Transduction
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Transcription Factors / genetics
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Transcription Factors / metabolism
Substances
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Arabidopsis Proteins
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DNA-Binding Proteins
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Indoleacetic Acids
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MONOPTEROS protein, Arabidopsis
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Transcription Factors