The GATA factor HANABA TARANU is required to position the proembryo boundary in the early Arabidopsis embryo Journal Article


Author(s): Nawy, Tal; Bayer, Martin; Mravec, Jozef; Friml, Jiří; Birnbaum, Kenneth D; Lukowitz, Wolfgang
Article Title: The GATA factor HANABA TARANU is required to position the proembryo boundary in the early Arabidopsis embryo
Affiliation
Abstract: Division of the Arabidopsis zygote defines two fundamentally different developmental domains, the proembryo and suspensor. The resulting boundary separates domain-specific gene expression, and a signal originating from the proembryo instructs the suspensor to generate the root stem cell niche. While root induction is known to require the phytohormone auxin and the Auxin Response Factor MONOPTEROS, it has remained largely elusive how the two domains involved in this process are initially specified. Here, we show that the GATA factor HANABA TARANU (HAN) is required to position the inductive proembryo boundary. Mutations in HAN cause a coordinated apical shift of gene expression patterns, revealing that HAN regulates transcription in the basal proembryo. Key auxin transporters are affected as early as the 8 cell stage, resulting in apical redistribution of auxin. Remarkably, han embryos eventually organize a root independent of MONOPTEROS and the suspensor around a new boundary marked by the auxin maximum.
Keywords: Mutation; Amino Acid Sequence; Molecular Sequence Data; Phenotype; plant roots; Gene Expression Regulation, Plant; Genes, Plant; Body Patterning; Gene Expression Regulation, Developmental; Arabidopsis; Arabidopsis Proteins; Indoleacetic Acids; Plants, Genetically Modified; Meristem; In Situ Hybridization; Amino Acid Substitution; GATA Transcription Factors
Journal Title: Developmental Cell
Volume: 19
Issue 1
ISSN: 1534-5807
Publisher: Cell Press  
Date Published: 2010-07-01
Start Page: 103
End Page: 113
DOI: 10.1016/j.devcel.2010.06.004
Open access: no