Molecular and biochemical characterization of a cytokinin oxidase from maize

K. D. Bilyeu, J. L. Cole, J. G. Laskey, W. R. Riekhof, T. J. Esparza, M. D. Kramer, R. O. Morris

Research output: Contribution to journalArticlepeer-review

184 Scopus citations


It is generally accepted that cytokinin oxidases, which oxidatively remove cytokinin side chains to produce adenine and the corresponding isopentenyl aldehyde, play a major role in regulating cytokinin levels in planta. Partially purified fractions of cytokinin oxidase from various species have been studied for many years, but have yet to clearly reveal the properties of the enzyme or to define its biological significance. Details of the genomic organization of the recently isolated maize (Zea mays) cytokinin oxidase gene (ckx1) and some of its Arabidopsis homologs are now presented. Expression of an intronless ckx1 in Pichia pastoris allowed production of large amounts of recombinant cytokinin oxidase and facilitated detailed kinetic and cofactor analysis and comparison with the native enzyme. The enzyme is a flavoprotein containing covalently bound flavin adenine dinucleotide, but no detectable heavy metals. Expression of the oxidase in maize tissues is described.

Original languageEnglish (US)
Pages (from-to)378-386
Number of pages9
JournalPlant physiology
Issue number1
StatePublished - 2001
Externally publishedYes

ASJC Scopus subject areas

  • Physiology
  • Genetics
  • Plant Science


Dive into the research topics of 'Molecular and biochemical characterization of a cytokinin oxidase from maize'. Together they form a unique fingerprint.

Cite this