Počet záznamů: 1  

Transient accumulation of cis- and trans-zeatin type cytokinins and its relation to cytokinin oxidase activity during cell cycle of synchronized tobacco BY-2 cells

  1. 1.
    0172240 - UEB-Q 20023019 RIV CZ eng J - Článek v odborném periodiku
    Dobrev, Petre - Motyka, Václav - Gaudinová, Alena - Malbeck, Jiří - Trávníčková, Alena - Kamínek, Miroslav - Vaňková, Radomíra
    Transient accumulation of cis- and trans-zeatin type cytokinins and its relation to cytokinin oxidase activity during cell cycle of synchronized tobacco BY-2 cells.
    Plant Physiology and Biochemistry. Roč. 40, - (2002), s. 333-337. ISSN 0981-9428
    Grant CEP: GA ČR GA522/99/1130; GA ČR GV206/96/K188; GA AV ČR IAA6038002
    Výzkumný záměr: CEZ:AV0Z5038910
    Klíčová slova: Cis zeatin * Cytokinins * Cytokinin oxidase
    Kód oboru RIV: EB - Genetika a molekulární biologie
    Impakt faktor: 1.582, rok: 2002

    Changes in levels of endogenous cytokinins and activity of cytokinin oxidase (EC 1.4.3.6) were followed during the cell cycle progression in large-scale (ca. 30 g FW) synchronized culture of the tobacco cell line BY-2. Synchronization was induced either by 4 mM hydroxyurea or 15 iM aphidicolin alone (a single block of the cell cycle at G,/S) or in combination with 1 uM oryzalin (double blocking at G,/S and Gz/M). Up to 46% synchrony was obtained. Two distinct cytokinin peaks were detected at 0-2 h and 8.5-9 h after the release from the first block coinciding with the beginning of the S phase and with the onset of mitosis, respectively. Interestingly, as identified by MS/MS, very sharp and transient premitotic peak of cytokinins contained, in addition to fra/u-zeatin, also considerable amounts of cu-zeatin and zeatin-0-glucoside. Cytokinin oxidase activity exhibited conspicuous maximum parallel to the first peak of cytokinin accumulation and deep minimum corresponding to the culmination of mitotic index. Possible roles of zeatin cis-trans isomerisation, glucosylation and degradation by cytokinin oxidase in regulation of cytokinin levels during the cell cycle progression are discussed.
    Trvalý link: http://hdl.handle.net/11104/0069279