Developmental Cell
Volume 19, Issue 1, 20 July 2010, Pages 103-113
Journal home page for Developmental Cell

Article
The GATA Factor HANABA TARANU Is Required to Position the Proembryo Boundary in the Early Arabidopsis Embryo

https://doi.org/10.1016/j.devcel.2010.06.004Get rights and content
Under an Elsevier user license
open archive

Summary

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.

Highlights

HAN specifies a gene expression domain at the base of the early proembryo ► The boundary between suspensor and proembryo shifts apically in han mutants ► Misregulation of PIN transporters creates an auxin maximum within the proembryo ► An ectopic root is eventually organized independent of the suspensor or MONOPTEROS

DEVBIO

Cited by (0)

5

Present address: Cell Biology Department, Max Planck Institute for Developmental Biology, Tübingen 72076, Germany