| Abstract Detail
Recent Topics Posters Volny, Matthew [1], Lukowitz, Wolfgang [1]. HAN GATA Transcription Factors Maintain Positional Coordinates during Arabidopsis thaliana embryogenesis. The GATA-type transcription factor HANABA TARANU (HAN) is a key regulator of transcriptional programs during Arabidopsis thaliana embryogenesis. Previous work has shown that HAN functions to maintain the inductive boundary between proembryo and suspensor cell lineages at which the root apical meristem (RAM) originates. Loss of HAN redirects auxin transport at the base of the embryo causing an apical shift in the fate map. However, the mutants eventually recover to form complete seedlings. To better understand the role of HAN in early embryonic patterning I have assessed the functional contribution of closely related GATA transcription factors in the HAN sub-family. I have determined by both gene swap experiments and multiple mutant analysis that two closely related genes, HAN-LIKE1 (HANL1) and HAN-LIKE2 (HANL2) are biochemically equivalent to HAN but, by themselves, not necessary for normal embryogenesis. In contrast, triple mutant embryos (han hanl1 hanl2) are more severely affected than han single mutants, as they never recover from their early defects and arrest as oblong structures with abnormally enlarged cells along their periphery. Genes which are normally expressed in the suspensor, become expressed in these enlarged surface cells in han hanl1 hanl2 embryos, while a gene expressed at the site of root initiation, WUSCHEL RELATED HOMEOBOX 5 becomes expressed in a continuous ring in the cell layer directly beneath. This striking pattern of gene expression may indicate a failure of these embryos to maintain normal positional coordinates and represents the first embryo patterning mutant of its kind in Arabidopsis thaliana. Broader Impacts:
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Keywords:
Arabidopsis
Development
Embryo.
Presentation Type: Recent Topics Poster
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PRT017
Abstract ID:1306
Candidate for Awards:None |
