Čeština
EnglishInhibition of Cytokinin-Glucose Conjugation in Derooted Radish, Tobacco and Bean Seedlings
Blagoeva, Elitsa; Dobrev, Petre; Vaňková, Radomíra
BULGARIAN JOURNAL OF PLANT PHYSIOLOGY 29 [1/2]: 13-30, 2003
Keywords: dihydrozeatin; cyclin-dependent kinase inhibitors; radish (Raphanus sativus L.)
Abstract: Four inhibitors of cyclin-dependent kinases, olomoucine, bohem-ine, roscovitine and isopropyl-olomoucine were tested for their ability to modify the conversion of exogenous tritiated dihydrozeatin ([3H]DHZ) in species differing in their pattern of cytokinin sequestering. In radish (Raph-anus sativus L.), species with predominant cytokinin N-glucosylation pathway, application of inhibitors (lOOuM) decreased conversion of [3H]DHZ into 7N- and 9N-glucosides. In common bean (Phaseolus vulgaris L.) cytokinin O-glucosylation is the prevailing deactivation mechanism and the tested inhibitors did not influence significantly the conversion of [3H]DHZ. The down-regulation of active cytokinin levels in tobacco (Nicotiana tabacum L.) is achieved by both 7N-glucosylation and degradation by cytokinin oxid-ase/dehydrogenase (CKX). The inhibition of 7N-glucosylation in this species stimulated the conversion of [3H]DHZ to nucleotide and riboside. The tested purine analogues have been proved to be selective inhibitors of cytokinin N-glucosylation with potential practical application.
DOI:
IEB authors: Petre I. Dobrev, Radomíra Vaňková
BULGARIAN JOURNAL OF PLANT PHYSIOLOGY 29 [1/2]: 13-30, 2003
Keywords: dihydrozeatin; cyclin-dependent kinase inhibitors; radish (Raphanus sativus L.)
Abstract: Four inhibitors of cyclin-dependent kinases, olomoucine, bohem-ine, roscovitine and isopropyl-olomoucine were tested for their ability to modify the conversion of exogenous tritiated dihydrozeatin ([3H]DHZ) in species differing in their pattern of cytokinin sequestering. In radish (Raph-anus sativus L.), species with predominant cytokinin N-glucosylation pathway, application of inhibitors (lOOuM) decreased conversion of [3H]DHZ into 7N- and 9N-glucosides. In common bean (Phaseolus vulgaris L.) cytokinin O-glucosylation is the prevailing deactivation mechanism and the tested inhibitors did not influence significantly the conversion of [3H]DHZ. The down-regulation of active cytokinin levels in tobacco (Nicotiana tabacum L.) is achieved by both 7N-glucosylation and degradation by cytokinin oxid-ase/dehydrogenase (CKX). The inhibition of 7N-glucosylation in this species stimulated the conversion of [3H]DHZ to nucleotide and riboside. The tested purine analogues have been proved to be selective inhibitors of cytokinin N-glucosylation with potential practical application.
DOI: