title: Functional characterization of the Arabidopsis transcription factor bZIP29 reveals its role in leaf and root development.
abstract: Plant bZIP group I transcription factors have been reported mainly for their role during vascular development and osmosensory responses. Interestingly, bZIP29 has been identified in a cell cycle interactome, indicating additional functions of bZIP29 in plant development. Here, bZIP29 was functionally characterized to study its role during plant development. It is not present in vascular tissue but is specifically expressed in proliferative tissues. Genome-wide mapping of bZIP29 target genes confirmed its role in stress and osmosensory responses, but also identified specific binding to several core cell cycle genes and to genes involved in cell wall organization. bZIP29 protein complex analyses validated interaction with other bZIP group I members and provided insight into regulatory mechanisms acting on bZIP dimers. In agreement with bZIP29 expression in proliferative tissues and with its binding to promoters of cell cycle regulators, dominant-negative repression of bZIP29 altered the cell number in leaves and in the root meristem. A transcriptome analysis on the root meristem, however, indicated that bZIP29 might regulate cell number through control of cell wall organization. Finally, ectopic dominant-negative repression of bZIP29 and redundant factors led to a seedling-lethal phenotype, pointing to essential roles for bZIP group I factors early in plant development.
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Jelle
authors.initials: J
authors.lastname: Van Leene
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Jonas
authors.initials: J
authors.lastname: Blomme
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Shubhada R
authors.initials: SR
authors.lastname: Kulkarni
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Bernard
authors.initials: B
authors.lastname: Cannoot
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Nancy
authors.initials: N
authors.lastname: De Winne
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Dominique
authors.initials: D
authors.lastname: Eeckhout
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Geert
authors.initials: G
authors.lastname: Persiau
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Eveline
authors.initials: E
authors.lastname: Van De Slijke
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Leen
authors.initials: L
authors.lastname: Vercruysse
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Robin
authors.initials: R
authors.lastname: Vanden Bossche
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Ken S
authors.initials: KS
authors.lastname: Heyndrickx
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Steffen
authors.initials: S
authors.lastname: Vanneste
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Alain
authors.initials: A
authors.lastname: Goossens
authors.affiliation: Department of Medical Protein Research, VIB, B-9000 Gent, Belgium Department of Biochemistry, Ghent University, B-9000 Gent, Belgium.
authors.forename: Kris
authors.initials: K
authors.lastname: Gevaert
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Klaas
authors.initials: K
authors.lastname: Vandepoele
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Gonzalez
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Inzé
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium geert.dejaeger@psb.vib-ugent.be.
authors.forename: Geert
authors.initials: G
authors.lastname: De Jaeger
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000502:physiology*; D020869:Gene Expression Profiling; D055106:Genome-Wide Association Study; D018519:Meristem / Q000254:growth & development; D018515:Plant Leaves / Q000254:growth & development*; D018517:Plant Roots / Q000254:growth & development*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors
keywords: 
  Arabidopsis thaliana
  ; bZIP group I transcription factors; cell proliferation; cell wall; chromatin immunoprecipitation; leaf cell number; plant development; root cell number; tandem affinity purification.