Naslov
Cytokinins in the Christmas rose (Helleborus niger L.)

Autori
Tarkowská, Danuše ; Salopek-Sondi, Branka ; Mihaljević, Snježana ; Tarkowski, Petr ; Strnad, Miroslav ; Magnus, Volker

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Zbornik sažetaka 8. Hrvatskog biološkog kongresa (Proceedings of Abstracts of the 8th Croatian Biological Congress ; ISBN 953-6241-05-6) / Besendorfer, Višnja ; Kopjar, Nevenka - Zagreb : Hrvatsko biološko društvo, 2003, 173-173

Skup
8. Hrvatski biološki kongres (8th Croatian Biological Congress)

Mjesto i datum
Zagreb, Hrvatska, 27.09.2003. - 02.10.2003

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
Christmas rose; Helleborus niger L.; flower and fruit development; cytokinin analysis

Sažetak
In fertilized flowers of the Christmas rose (Helleborus niger L.), the sepals (initially white) develop functional chloroplasts and persist until the seeds are ripe. In unfertilized flowers, the greening process may be initiated by treatment with exogenous cytokinins. The biologically active endogenous cytokinins and their reversible conjugates in fruit-bearing flowers were analyzed by a combination of chromatographic methods and mass spectrometry. Trans- and cis-zeatin, dihydrozeatin, N^6-(2-isopentenyl)adenine, and the corresponding O-glucosides, riboside O-glucosides, and ribotides were detected, in addition to minor amounts of aromatic cytokinins (e. g. N^6-benzyladenine). In the fruit, the overall level of active cytokinins increased enormously, during early seedling growth, and remained high until ~2 weeks before ripening (most advanced stage checked so far), possibly because embryo development is not complete and continues after the seeds are shed. In the sepals, only the concentrations of cis-zeatin riboside and ribotide were about the same, or higher than, in the fruit from the same flowers and increased consistently during the greening process, while the levels of the other cytokinins examined remained low and showed no obvious systematic changes.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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