caa a22 4500 463159721 CHVBK 20180406164744.0 cr unu---uuuuu 170326e20070301xx s 000 0 eng 10.1007/s10535-007-0039-3 doi (NATIONALLICENCE)springer-10.1007/s10535-007-0039-3 Developmental stage as a possible factor affecting cytokinin content and cytokinin dehydrogenase activity in Pinus sylvestris [Elektronische Daten] [A. Valdés, P. Galuszka, B. Fernández, M. Centeno, I. Frébort] In the present study cytokinin dehydrogenase (CKX) activity was for the first time found in a conifer species, Pinus sylvestris. The activities were correlated with the endogenous cytokinin contents. Several enzyme substrates and two different electron acceptors were used to search for the enzyme activity in the extract from seeds, seedlings and plantlets. The highest specific activity was found in one-year-old plantlets with isopentenyladenine as the substrate and 2,6-dichlorophenolindophenol as the electron acceptor, at pH 8. An enhancement in the CKX specific activity corresponded to increasing contents of cytokinins, mainly isopentenyladenine and isopentenyladenosine, indicating that the enzyme activity is affected by the endogenous supply of cytokinins. CKX affinity for the ribosylated form of isopentenyladenine was dependent on the developmental stage, being higher in seeds than in seedlings, and not detectable in plantlets. The results are indicative of the presence of different isoenzymes throughout the development. Institute of Experimental Botany, ASCR, 2007 cytokinin metabolism nationallicence conifers nationallicence plant ageing nationallicence (2-OH)BA : N 6-(2-hydroxybenzyl)adenine nationallicence CKX : cytokinin dehydrogenase nationallicence DCPIP : 2,6-dichlorophenolindophenol nationallicence DHZ : dihydrozeatin nationallicence DHZR : dihydrozeatin riboside nationallicence iP : N 6-isopentenyladenine nationallicence iPR : N 6-isopentenyladenosine nationallicence Q0 : 2,3-dimethoxy-5-methyl-1,4-benzoquinone nationallicence Z : zeatin nationallicence ZR : zeatin riboside nationallicence Valdés A. Departamento de Biología de Organismos y Sistemas, Universidad de Oviedo, c/ Catedrático Rodrigo Uría, s/n, E-33071, Oviedo, Spain aut Galuszka P. Faculty of Science, Palacký University, Šlechtitelů 11, CZ-78371, Olomouc, Czech Republic aut Fernández B. Departamento de Biología de Organismos y Sistemas, Universidad de Oviedo, c/ Catedrático Rodrigo Uría, s/n, E-33071, Oviedo, Spain aut Centeno M. Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana, León, Spain aut Frébort I. Faculty of Science, Palacký University, Šlechtitelů 11, CZ-78371, Olomouc, Czech Republic aut Biologia Plantarum Springer Netherlands 51/1(2007-03-01), 193-197 0006-3134 51:1<193 2007 51 10535 https://doi.org/10.1007/s10535-007-0039-3 text/html Onlinezugriff via DOI 1 brief-communication jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10535-007-0039-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Valdés A. Departamento de Biología de Organismos y Sistemas, Universidad de Oviedo, c/ Catedrático Rodrigo Uría, s/n, E-33071, Oviedo, Spain aut NATIONALLICENCE 700 1- Galuszka P. Faculty of Science, Palacký University, Šlechtitelů 11, CZ-78371, Olomouc, Czech Republic aut NATIONALLICENCE 700 1- Fernández B. Departamento de Biología de Organismos y Sistemas, Universidad de Oviedo, c/ Catedrático Rodrigo Uría, s/n, E-33071, Oviedo, Spain aut NATIONALLICENCE 700 1- Centeno M. Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana, León, Spain aut NATIONALLICENCE 700 1- Frébort I. Faculty of Science, Palacký University, Šlechtitelů 11, CZ-78371, Olomouc, Czech Republic aut NATIONALLICENCE 773 0- Biologia Plantarum Springer Netherlands 51/1(2007-03-01), 193-197 0006-3134 51:1<193 2007 51 10535 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer