This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Synonyms: Cytokinins oxidation
|Superclasses:||Degradation/Utilization/Assimilation → Hormones Degradation → Plant Hormones Degradation → Cytokinins Degradation|
Expected Taxonomic Range: Viridiplantae
Cytokinins, which are N6-substituted purine derivatives, are a class of plant hormones that plays important physiological roles in plants, from promotion of cell division, to release of lateral buds from apical dominance or delay of senescence. Cytokinin homeostasis is regulated by the rate of biosynthesis, import, conjugation (mainly in the form of glycosides) and degradation. Cytokinins are irreversibly degraded by cytokinin oxidases which catalyse cleavage of the N6-isopentenyl-side chain resulting in formation of adenine-type compounds. Cytokinins isopentenyladenine, zeatins and their ribosides are cleaved in a single enzymatic step by oxidative side chain cleavage. This activity has been recorded in many plants and is thought to plant a key role in controlling cytokinin levels in plants.
Unification Links: AraCyc:PWY-2841
Bilyeu01: Bilyeu KD, Cole JL, Laskey JG, Riekhof WR, Esparza TJ, Kramer MD, Morris RO (2001). "Molecular and biochemical characterization of a cytokinin oxidase from maize." Plant Physiol 125(1);378-86. PMID: 11154345
Schmulling03: Schmulling T, Werner T, Riefler M, Krupkova E, Bartrina y Manns I (2003). "Structure and function of cytokinin oxidase/dehydrogenase genes of maize, rice, Arabidopsis and other species." J Plant Res 116(3);241-52. PMID: 12721786
Kasahara04: Kasahara H, Takei K, Ueda N, Hishiyama S, Yamaya T, Kamiya Y, Yamaguchi S, Sakakibara H (2004). "Distinct isoprenoid origins of cis- and trans-zeatin biosyntheses in Arabidopsis." J Biol Chem 279(14);14049-54. PMID: 14726522
Nouws75: Nouws JF (1975). "[Distribution of Rifamycin SV in de Bovine Tissues Following Intramammary Administration of Rifamastene (author's transl)]." Tijdschr Diergeneeskd 100(10);539-45. PMID: 1154345
Takei04: Takei K, Yamaya T, Sakakibara H (2004). "Arabidopsis CYP735A1 and CYP735A2 encode cytokinin hydroxylases that catalyze the biosynthesis of trans-Zeatin." J Biol Chem 279(40);41866-72. PMID: 15280363
Werner03: Werner T, Motyka V, Laucou V, Smets R, Van Onckelen H, Schmulling T (2003). "Cytokinin-deficient transgenic Arabidopsis plants show multiple developmental alterations indicating opposite functions of cytokinins in the regulation of shoot and root meristem activity." Plant Cell 15(11);2532-50. PMID: 14555694
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