Summary
Plant post-embryonic development takes place in the meristems, zones of actively dividing cells. Meristems contain populations of stem cells that self-renew and produce daughter cells that differentiate giving rise to different organ structures. Using mainly molecular genetic approaches plant stem cell and meristem maintenance, our research has identified the major players in the underlying developmental pathways, encoding a variety of proteins involved in transcriptional regulation. However, their regulation at the protein level is largely unknown and requires detailed knowledge of the composition of cell-specific complexes.
The lab has studied in detail the function of an Arabidopsis transcription factor network that is required for stem cell specification and cell differentiation. Examples or proteins residing in this network are: Retinoblastoma-related, Shortroot, Scarecrow and Plethora proteins. Yeast-two-hybrid and split YFP assays suggest numerous interations between members of this network and identify TCP proteins as components that interact with multiple members of the network. All transcription factors can be immunoprecipitated by specific antibodies or using tags which have been verified to maintain protein activity. Our aim is to validate protein interactions in vivo and to extend knowledge of protein complexes by mass spectrometry analysis of associated proteins. Since genetic and genomic data suggest that different cell types contain different complexes, we need to establish IP protocols on sorted cell types. This will open up a new area in proteomics technology and will allow us to understand stem cells in plants.