Effect of the suicide inhibitors of arginine and ornithine decarboxylase activities on organogenesis, growth, free polyamine and hydroxycinnamoyl putrescine levels in leaf explants of Nicotiana xanthi n.c. cultivated in vitro in a medium producing callus formation

We studied the effects of DL- alpha -difluoromethylarginine and Dl- alpha -difluoromethyl ornithine (DFMO), specific, irreversible inhibitors of arginine decarboxylase (ADC) and ornithine decarboxylase (ODC), respectively, on organogenesis growth and titers of free polyamines and conjugated putrescines (hydroxycinnamoyl putrescines) in tobacco (Nicotiana tabacum cv Xanthi n.c.) calli. The results suggest that ADC and ODC regulate putrescine biosynthesis during early and later stages of tobacco callus development, respectively. (DBO)