1. Institut für Zelluläre und Molekulare Botanik, Universität Bonn, Kirschallee 1, D53115, Bonn, Germany
2. Institute of General Botany, Faculty of Biology, University of Athens, GR15784, Greece
3. Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Cell Biology, Faculty of Science, Palacký University, 783 01 Olomouc, Czech Republic