0172354 - UEB-Q 20033121 RIV DK eng J - Journal Article
Werner, Tomáš - Hanuš, Jan - Holub, Jan - Schmülling, T. - Onckelen, H. V. - Strnad, Miroslav
New cytokinin metabolites in IPT transgenic Arabidopsis thaliana plants.
Physiologia Plantarum. Roč. 118, č. 1 (2003), s. 127-137. ISSN 0031-9317. E-ISSN 1399-3054
R&D Projects: GA ČR GA301/02/0475
Grant - others:Volkswagen Stiftung(DE) I/76 86:153100008; - - -(BE) IUAP P5/13
Institutional research plan: CEZ:AV0Z5038910
Keywords : transgenic Arabidopsis thaliana * cytokinin * zeatin-O-glucoside
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 1.767, year: 2003

Two novel cytokinin metabolites were identified in transgenic Arabidopsis thaliana (L.) Heynh. plants containing the bacterial IPT gene under the transcriptional control of a heat-regulated promoter. After cyclic heat-shock treatment, the endogenous cytokinin concentrations were elevated up to 100-fold compared to the wild-type plants. More then 20 different cytokinin metabolites were found, with zeatin-type cytokinins being the most abundant. The metabolic inactivation of these compounds occurred predominantly through N-glucosylation. No significant accumulation of isopentenyladenine-type cytokinins, and only a small increase in dihydrozeatin metabolites, was observed. Subsequent studies of the abundant, unidentified conjugates revealed the presence of zeatin and dihydrozeatin diglucoside conjugates. Structural analysis, utilizing electrospray-liquid tandem mass spectrometry, identified these as a zeatin-O-glucoside-9-glucoside and dihydrozeatin-O-glucoside-9-glucoside, respectively. A third unknown metabolite, was tentatively identified as a phosphorylated form of zeatin-9-glucoside.
Permanent Link: http://hdl.handle.net/11104/0069393