1. Institute of Experimental Botany, v. v. i. Academy of Sciences of the Czech Republic 16502 Prague 6 Czech Republic
2. Institut des Neurosciences Cellulaires et Integratives CNRS UPR3212 and Université de Strasbourg Strasbourg France
3. Department of Biology University of Erlangen‐Nuremberg 91058 Erlangen Germany
4. Department of Experimental Plant Biology Faculty of Science Charles University in Prague 128 44 Prague 2 Czech Republic