Abstracts (poster) - Wissenschaft Online

Peter R. Lange, Andreas Finke, Claus Wasternack
TFL2 as an epigenetic regulator in Arabidopsis development
A stable repression of gene expression in connection with the inheritance of an
established transcription pattern from cell to cell is an important aspect of eukaryotic
development. Specific combinations of DNA and histone modifications cause local
alterations of the chromatin structure and determine the balance between
heterochromatin and euchromatin. To initiate gene silencing for example the polycomb
repressor complex 2 (PRC2) transfers methyl-groups to specific histone domains. In
animal species this is translated to a stable repression of the corresponding chromatin
domain by the polycomb repressor complex 1 (PRC1). However, in plants PRC1 is
neither structurally nor mechanistically conserved. One possible component of PRC2
dependent maintenance of gene silencing is TERMINAL FLOWER 2 (TFL2). TFL2 was
found to associate with H3K27 tri-methylated euchromatic genes (Turck, 2007). The loss
of TFL2 in Arabidopsis thaliana leads to homeotic alterations in the architecture of
inflorescences and flowers. Constitutive TFL2 over-expression lines generated during our
work also show distinct alterations in inflorescences and the branching pattern.
Molecular analyses mainly focused either on the mechanisms of epigenetic regulation or
on individual target genes. In our work we used the comparison of the tfl2, 35S::TFL2
and wild-type genome-wide transcriptomes to identify specific target genes of TFL2. We
aim to uncover and to functionally characterize target genes of TFL2 involved in plant
development.
Our analysis of the tfl2 mutant transcriptome revealed 199 and 335 significantly up- or
down-regulated genes, respectively. After vigorous selection from the pool of deregulated
genes we are in the process of screening 60 insertion mutant lines for
alterations in the plant architecture. A genetic and molecular characterisation of the
corresponding genes giving rise to developmental phenotypes will be carried out to
define their role in the determination of A. thaliana development.
Literature
Turck F., et al. (2007) PLoS Genet 3(6) e86. doi:10.1371/journal.pgen.0030086
contact:
Dr. Peter Lange
Leibniz-Institut für Pflanzenbiochemie
plange@ipb-halle.de
Weinberg 3
06120 Halle/Saale (Germany)