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.

• Tissue-Autonomous Phenylpropanoid Production Is Essential for Establishment of Root Barriers
  Andersen, Tonni Grube; Molina, David; Kilian, Joachim; Franke, Rochus B.; Ragni, Laura; et al.
  Current Biology 10.1016/j.cub.2020.11.070 Published: MAR 8 2021
• Signatures of antagonistic pleiotropy in a bacterial flagellin epitope
  Parys, Katarzyna; Colaianni, Nicholas R.; Lee, Ho-Seok; Hohmann, Ulrich; Edelbacher, Natalie; et al.
  Cell Host & Microbe  10.1016/j.chom.2021.02.008 Published: APR 14 2021
• GDSL-domain proteins have key roles in suberin polymerization and degradation
  Ursache, Robertas; Teixeira, Cristovao De Jesus Vieira; Tendon, Valerie Denervaud; Gully, Kay; De Bellis, Damien; Schmid-Siegert, Emanuel; Andersen, Tonni Grube; Shekhar, Vinay; Calderon, Sandra; Pradervand, Sylvain; Nawrath, Christiane; Geldner, Niko; Vermeer, Joop E. M
  Nature Plants  10.1038/s41477-021-00862-9 Published: MAR 2021
• Spatially Restricted Immune Responses Are Required for Maintaining Root Meristematic Activity upon Detection of Bacteria
  Emonet, Aurelia; Zhou, Feng; Vacheron, Jordan; Heiman, Clara Margot; Tendon, Valerie Denervaud; et al.
  Current Biology   10.1016/j.cub.2020.12.048  Published: MAR 8 2021
• Plant roots employ cell-layer-specific programs to respond to pathogenic and beneficial microbes
  Froschel, Christian; Komorek, Jaqueline; Attard, Agnes; Marsell, Alexander; Lopez-Arboleda, William A.; et al.
  Cell Host & Microbe  10.1016/j.chom.2020.11.014 Published: FEB 10 2021
• High-order mutants reveal an essential requirement for peroxidases but not laccases in Casparian strip lignification
  Rojas-Murcia, Nelson; Hematy, Kian; Lee, Yuree; Emonet, Aurelia; Ursache, Robertas; Fujita, Satoshi; De Bellis, Damien; Geldner, Niko
  Proceedings Of The National Academy Of Sciences Of The United States Of America 10.1073/pnas.2012728117   Nov 2020
• SCHENGEN receptor module drives localized ROS production and lignification in plant roots
  Fujita, Satoshi; De Bellis, Damien; Edel, Kai H.; Koester, Philipp; Andersen, Tonni Grube; Schmid-Siegert, Emanuel; Tendon, Valerie Denervaud; Pfister, Alexandre; Marhavy, Peter; Ursache, Robertas; Doblas, Veronica G; Barberon, Marie; Daraspe, Jean; Creff, Audrey; Ingram, Gwyneth; Kudla, Joerg; Geldner, Niko
  Embo Journal   DOI: 10.15252/embj.2019103894  MAR 2020
• A two-way molecular dialogue between embryo and endosperm is required for seed development
  Doll, N. M.; Royek, S.; Fujita, S.; Okuda, S.; Chamot, S.; Stintzi, A; Widiez, T; Hothorn, M; Schaller, A; Geldner, N; Ingram, G
  Science  367(6476): 431-+ SI DOI: 10.1126/science.aaz4131 JAN 24 2020
• Co-incidence of Damage and Microbial Patterns Controls Localized Immune Responses in Roots
  Zhou, Feng; Emonet, Aurelia; Tendon, Valerie Denervaud; Marhavy, Peter; Wu, Dousheng; Lahaye, Thomas; Geldner, Niko
  Cell  180(3): 440-+ DOI: 10.1016/j.cell.2020.01.013 FEB 6 2020
• Molecular mechanism for the recognition of sequence-divergent CIF peptides by the plant receptor kinases GSO1/SGN3 and GSO2
  Okuda, Satohiro; Fujita, Satoshi; Moretti, Andrea; Hohmann, Ulrich; Doblas, Veronica G.; Ma, Y; Pfister, A; Brandt, B; Geldner, N; Hothorn, M
  Proceedings Of The National Academy Of Sciences Of The United States Of America, 10.1073/pnas.1911553117, FEB 4 2020
• Root endodermal barrier system contributes to defence against plant-parasitic cyst and root-knot nematodes
  Holbein, J; Franke, RB; Marhavy, P; Fujita, S; Gorecka, M; Sobczak, M; Geldner, N; Schreiber, L; Grundler, FMW; Siddique, S
  PLANT JOURNAL, 10.1111/tpj.14459 Published: OCT 2019
• Single-cell damage elicits regional, nematode-restricting ethylene responses in roots
  Marhavy, P; Kurenda, A; Siddique, S; Tendon, VD; Zhou, F; Holbein, J; Hasan, MS; Grundler, FMW; Farmer, EE; Geldner, N
  EMBO JOURNAL, 38 (10):10.15252/embj.2018100972 MAY 15 2019
• …

• The root endodermis as a polar epithelium 
• Receptor trafficking in plants 
• Waves lines: Mapping the complexity of the plant membrane system

• WAVE lines: a set of fluorescent markers for plant membrane compartments
• The pNIGEL recombination vector series
• Live cell imaging
• Forward and reverse genetic screens
• Proteomic approaches