Molecular Genetics and Plant Cell Biology

Multicellular organisms cope with the challenge of maintaining efficient communication between different organs and tissues to coordinate growth and responses to the environment. Both, plants and animals produce biologically active compounds such as small peptides that move between cells through the vascular system or intercellular spaces and regulate plethora of developmental processes and stress responses. In plants, in addition to major hormones, a myriad of secreted peptides orchestrates optimal growth and adaptation to environmental changes. Our lab is interested to unravel the functions of the CLAVATA3/EMBRYO SURROUNDING REGION (CLE) peptides and their cognate receptors in the control of the water conducting tissue formation and in the plant adaptation to abiotic stresses. In addition, we aim to develop new tools to tag and track the precursors and mature CLE peptides in planta. In collaboration with structural biology and organic chemistry laboratories as well as with our Proteomics Platform at UniFR, we use a combination of genetic approaches, molecular design, proteomics, cell biology, high-resolution confocal microscopy and plant physiology assays.

• A Cellular Insulator against CLE45 Peptide Signaling
  Breda, AS; Hazak, O; Schultz, P; Anne, P; Graeff, M; Simon, R; Hardtke, CS
  CURRENT BIOLOGY, 29 (15):2501-+; 10.1016/j.cub.2019.06.037 AUG 5 2019
• Perception of root-active CLE peptides requires CORYNE function in the phloem vasculature 
  Hazak, Ora; Brandt, Benjamin; Cattaneo, Pietro; Santiago, J; Rodriguez-Villalon, A; Hothorn, M; Hardtke, CS
  EMBO REPORTS, 18 (8): 1367-1381 https://doi.org/10.15252/embr.201643535 AUG 2017
• Phosphosite charge rather than shootward localization determines OCTOPUS activity in root protophloem
  Breda, Alice S.; Hazak, Ora; Hardtke, Christian S.
  PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 114(28): E5721-E5730  10.1073/pnas.1703258114  JUL 11 2017
• CLAVATA 1-type receptors in plant development
  Hazak, Ora; Hardtke, Christian S.
  JOURNAL OF EXPERIMENTAL BOTANY 67 (16), SI:4827-4833 10.1093/jxb/erw247 AUG 2016
• Bimodal regulation of ICR1 levels generates self-organizing auxin distribution
  Hazak, Ora; Obolski, Uri; Prat, Tomas; Friml, J; Hadany, L; Yalovsky, S.
  PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA   111 10.1073/pnas.1413918111  2014

• Plant signaling peptides and receptors
• Xylem development
• Adaptations to abiotic stresses

• Developing tools to tag and track CLE peptides in vivo (in collaboration with Dr. Roy Weinstain, Tel Aviv University, Israel)
• Testing the glycosylation of the receptors (in collaboration with Dr. Sabina Gerber, ZHAW, Zurich)
• Peptides detection methods (Proteomics platform, UniFR)