Himanen, K , Nelissen, H , Fleury, D , Cnops, G , Boccardi, T , Inze, D , Van Lijsebettens, M .
Growth control in plants by chromatin modifying complexes.
We use Arabidopsis leaves as an experimental system to study the genetic/epigenetic control of organ formation in plants. Leaf architecture is important in green biomass production and basic knowledge on the molecular-genetic network controlling leaf size and shape will contribute to the improvement of plants for applied research.
Growth occurs mainly in two dimensions and final leaf size and shape is determined by cell number and cell volume. Over the last decades, a number of transcription factors have been identified that control leaf initiation and early stages in patterning and growth. The next step in the research is to identify and study the upstream mechanisms that regulate transcription factors or the cell cycle machinery. Our results show that histone modification is one of these upstream regulatory mechanisms since two classes of the EMS induced leaf mutants (Berna et al., 1999) identified chromatin modifying complexes, both affecting organ formation by regulating cell number. The Elongator complex contains a histone acetyl transferase and was shown to act in the processs of RNA polymerase II transcription elongation downstream of Mediator; the HUB1 E3 ubiquitin ligase complex has histone H2B monoubiquitination activity resulting in transcription activation of a large number of core cell cycle genes (Nelissen et al., 2005, PNAS 102, 7754-7759; Fleury et al., Plant Cell, in press). The positioning of Elongator and HUB1 in genetic and molecular networks using double mutants, transcriptome analysis and protein-protein interactions, will be discussed.
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1 - VIB/ Ghent University, Plant Systems Biology
2 - VIB/ Ghent University, Plant Systems Biology, Technologiepark 927, 9052, Gent, Belgium
Presentation Type: ASPB Minisymposium
Location: Continental B/Hilton
Date: Sunday, July 8th, 2007
Time: 3:15 PM