Impact of the cell wall on cell polarization and morphogenesis in the stomatal lineage.

• Applicant: Dr. Martin Bringmann
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2013 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 241170743

Getting in shape with the cell wall: How modifications in the cell wall affect polarization and differentiation in the stomatal lineageIn plants, cell shape is generated by cell walls that surround the cells and counteract the internal turgor pressure. As a consequence, differentiation of walled cells is tightly linked to local changes in wall properties. How exactly cell walls adjust during developmental processes and how they contribute to cell differentiation is as of yet unknown.The stomatal lineage of the leaf epidermis is well suited to explore how different cell types arise though the activity of fate specifiers and the downstream processes of cellular behavior and morphogenesis. Stomatal lineage cells are produced by asymmetric cell divisions of polarized cells. The research I propose here elucidates links between polarization and differentiation processes and changes in the cell wall.My preliminary data suggest a specific effect of the CELLULOSE SYNTHASE LIKE 5 (CSLD5) gene, which is expressed during the stomatal lineage, on polarization of the BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE (BASL) protein and consequently on asymmetric cell divisions. Further candidate genes that potentially link cell wall modification to stomatal development arose from a co- expression screen conducted in the Bergmann lab, covering four distinct stages of the stomatal lineage.Besides the characterization of candidate genes with reference to the cell wall, I will identify and characterize new interaction partners of the polarized proteins in the stomatal lineage through co- immunoprecipitation and mass spectrometry.The proposed research aims to gain knowledge in a bi- directional fashion. On the one hand it will tackle a large gap in our knowledge about how the specific divisions and final physical properties of stomata are generated. At the same time, use of the experimentally tractable stomata system may allow us to identify principles of the connection between cell identity, cell polarity and cell wall properties that that can apply to many other plant cell types.

• DFG Programme: Research Fellowships
• International Connection: USA
• Host: Professorin Dr. Dominique Bergmann