title: Partial auxin deprivation affects endogenous cytokinins in an auxin-dependent, cytokinin-independent tobacco cell strain.
abstract: The dynamics of individual endogenous cytokinins within the growth cycle (subculture interval) of an auxin-dependent and cytokinin-independent cell suspension culture ofNicotiana tabacum L. (strain VBI-0) were determined using high performance liquid chromatography and radioimmunoassay. In cells grown at an optimum auxin concentration the transient maxima of N(6)-(Δ(2)-isopentenyl)adenine and N(6)-(Δ(2)-isopentenyl)-adenosine correlated with the onset of cell division. Cultivation of the cells in a partially auxin-deprived medium resulted in ca. tenfold increase of all endogenous cytokinins. A very distinct maximum of N(6)-(Δ(2)-sopentenyl) adenine appeared at the beginning of subculture. This indicates that a lack of auxin induced an accumulation of cytokinins predominantly in the form of the free bases, which are physiologically more active than the corresponding ribosides.
authors.affiliation: De Montford University Norman Borlaug Centre for Plant Science, Institute of Experimental Botany ASCR, Ke dvoru 16/15, 166 30, Prague 6, Czech Republic.
authors.forename: E
authors.initials: E
authors.lastname: Zažímalová
authors.forename: A
authors.initials: A
authors.lastname: Březinová
authors.forename: J
authors.initials: J
authors.lastname: Holík
authors.forename: Z
authors.initials: Z
authors.lastname: Opatrný