1. Laboratory of Growth Regulators and Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, CZ 78371 Olomouc, Czech Republic
2. On leave from Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany;
3. Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37077 Goettingen, Germany;