Isolation of two cytokinin metabolites from the rhizosphere of Norway spruce seedlings (Picea abies L. Karst.)

TLDR: In this paper, young Norway spruce seedlings were incubated under hydroculture conditions in a synthetic nutrient medium containing either 3H-isopentenyladenosine, isopenteniene, or zeatin riboside.

Abstract: Roots of young Norway spruce seedlings were incubated under hydroculture conditions in a synthetic nutrient medium containing either 3H-isopentenyladenosine, isopentenyladenosine or zeatin riboside. When feeding with 3H-isopentenyladenosine a new radiaolabelled metabolite was found in the feeding solution as well as in root extracts. Isopentenyladenosine and zeatin riboside were metabolised and for both compounds an unknown metabolite was detected in the feeding solution. The metabolites were purified by solid phase extraction, HPLC and partially characterised. A major characteristic of the metabolites is their reactivity in the presence of NH4OH, which results in the formation of the cytokinin bases isopentenyladenine or zeatin, respectively. UV-spectra and the chemical characteristics indicate that the new metabolites are closely related. The GC-MS analysis revealed, that the metabolites are true derivatives of isopentenyladenine and zeatin. The biogenesis of the new metabolites is discussed with regard to plant microbial interactions.