Auxin triggers transient local signaling for cell specification in Arabidopsis embryogenesis.
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.
Weijers
Dolf
D
ZMBP Entwicklungsgenetik, Universität Tübingen, Auf der Morgenstelle 3, D-72076 Tübingen, Germany.
Schlereth
Alexandra
A
Ehrismann
Jasmin S
JS
Schwank
Gerald
G
Kientz
Marika
M
Jürgens
Gerd
G
D017360:Arabidopsis / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001693:Biological Transport, Active; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D018519:Meristem / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D018517:Plant Roots / Q000196:embryology / Q000378:metabolism; D030821:Plants, Genetically Modified; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D007210:Indoleacetic Acids; C111371:MONOPTEROS protein, Arabidopsis; D014157:Transcription Factors