1. Institute of Chemistry, University of Białystok, al. Pilsudskiego 11/4, 15-443 Bialystok, Poland, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, ul. Pawinskiego 5a, 02-106 Warsaw, Poland, and Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Slechtitelu 11, 78371 Olomouc, Czech Republic