One of our main topics of interest is the study of endodermis as an invariant feature of vascular plants. It fulfils a crucial barrier function separating the extracellular space of outer cell layers from the inner apoplastic space of the vascular bundles. The "Casparian strip" has been defined as an area where endodermal cells secrete hydrophobic material in a highly localised and coordinated fashion to act as a barrier. The Casparian strip is composed of a ligno-suberic polymer, which forms an extensive, supra-cellular network.
We demonstrate that there is no lateral diffusion across the Casparian Strip Domain (CSD) between outer and inner plasma membrane domains and we have identified transporters that localise to one or the other membrane region, depending on their function in uptake or efflux of nutrients. In addition we identified a new class of proteins that mark and predict the formation of the CSD. We will investigate the mechanisms underlying the formation of the Casparian Strip sub-domain on cellular surface and the localisation of proteins to either its central or peripheral side.
Prof. Dr. Niko Geldner
University of Lausanne
Department of Plant Molecular Biology
1015 Lausanne
Tel: +41 21 692 4192