Laboratoř růstových regulátorů, PřF UP Olomouc a ÚEB AV ČR Laboratory of Growth Regulators, Faculty of Science, Palacký University in Olomouc and Institute of Experimental Botany ASCR, Czech Republic Xanthine dehydrogenase and cytokinin metabolism Jitka Frébortová Cytokinin meeting, Olomouc, September 8, 2011
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Laboratoř růstových regulátorů, PřF UP Olomouc a ÚEB AV ČR Laboratory of Growth Regulators, Faculty of Science, Palacký University in Olomouc and Institute.
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Laboratoř růstových regulátorů, PřF UP Olomouc a ÚEB AV ČR
Laboratory of Growth Regulators, Faculty of Science, Palacký University in Olomouc and Institute of Experimental Botany ASCR, Czech Republic
Xanthine dehydrogenase and cytokinin metabolism
Jitka Frébortová
Cytokinin meeting, Olomouc, September 8, 2011
Xanthine oxidoreductase
NHN
NNH
O
NHN
NNH
O
O
Hypoxanthine
NHN
NNH
O
O
O
Xanthine Uric acid
XO/XDH XO/XDH
Werner and Witte (2011) Trends Plant Sci. 16, 381-387.
Interaction of cytokinins with bovine milk xanthine oxidase
NHN
NN
NHR
NHN
NN
NHR
OHNHN
NN
NHR
OH
OH
max = 269 nm max = 275 nm max = 306 nm(pH 7, iP, tZ)
Chen et al. (1975) Biochemistry 14, 3088-3093.
Cytokinins described also as inhibitors of bovine milk XO Conversion of cytokinins to 8-hydroxyderivatives confirmed
also in rhizobacterium Serratia protemaculans
XO XO
Sheu et al. (1996) Anticancer Res. 16, 3571-3576. Sheu et al. (1997) Anticancer Res. 17, 1043-1050.Taylor et al. (2006) Phytochemistry 67, 1887-1894.
Plant xanthine dehydrogenase and cytokinin metabolism
Is AtXDH1 converting cytokinins?
Are cytokinins substrates or inhibitors of XORs?
Are the relevant metabolites present in plants?
Biological activity of 8-OH and 2,8-OH cytokinins
Cytokinin free bases are substrates of AtXDH1 and milk XO