Laboratory of Cell Morphogenesis
Principal Investigators: Viktor Žárský and Fatima Cvrčková
The laboratory is part of the Department of Experimental Plant Biology at the Faculty of Sciences, Charles University, and is closely linked to the Laboratory of Cell Biology at the Institute of Experimental Botany, ASCR.
Our research
The main focus of our research is on molecular mechanisms of plant cell polarity.
Since plant cells are enclosed in a rigid cell wall, they cannot migrate. All plant mophogenesis, both on the level of a single cell and on the multicellular body level, must thus be accomplished by oriented cell division and polarized cell growth. Both of these processes are critically dependent on the cells´ ability to deliver compounds and structures (such as, e.g., secretory vesicles) to distinct parts of its surface (or distinct intracellular compartments). Polarized exocytosis is also unseparable from membrane recycling, and thus from the context of the whole endomembrane system.
The above image (from Žárský et al. 2009) presents a summary of known signalling proteins participating in the establishment and function of an activated cortical domain (ACD) - an area of the cell surface engaged in active membrane turnover.
The ACD model can be viewed as an unifying concept aiding the understanding not only various modes of cell expansion, but also the building of the cell plate during cytokinesis, as well as processes involving localized plasmalemma expansion triggered by biotic interactions, as illustrated in this schematic (from Cvrčková et al. 2024), where areas of vigorous plasmalemma turnover corresponding to the ACDs are marked in yellow.
The laboratory focuses mainly on evolutionarily conserved proteins and protein complexes participating in polarised exocytosis and cytoskeletal organisation, namely:
the exocyst complex
formins (FH2 proteins), a family of cytoskeletal organizers
(phospho)lipid signalling
roles of the above systems in the response of plant cells towards pathogens
other topics mostly related to the establishment and maintenance of plant cell polarity and to the reconstruction of plants´ and cells´evolutionary history.
Our main model systems are Arabidopsis thaliana and Physcomitrium patens plants, with other systems (such as tobacco pollen) employed in certain studies.