ISOLATION OF 2 CYTOKININ METABOLITES FROM THE RHIZOSPHERE OF NORWAY SPRUCE SEEDLINGS (PICEA-ABIES L KARST)

Roots of young Norway spruce seedlings were incubated under hydrocultu re conditions in a synthetic nutrient medium containing either H-3-iso pentenyladenosine, isopentenyladenosine or zeatin riboside. When feedi ng with H-3-isopentenyladenosine a new radiaolabelled metabolite was f ound in the feeding solution as well as in root extracts. Isopentenyla denosine and zeatin riboside were metabolised and for both compounds a n unknown metabolite was detected in the feeding solution. The metabol ites were purified by solid phase extraction, HPLC and partially chara cterised. A major characteristic of the metabolites is their reactivit y in the presence of NH4OH, which results in the formation of the cyto kinin bases isopentenyladenine or zeatin, respectively. UV-spectra and the chemical characteristics indicate that the new metabolites are cl osely related. The GC-MS analysis revealed, that the metabolites are t rue derivatives of isopentenyladenine and zeatin. The biogenesis of th e new metabolites is discussed with regard to plant microbial interact ions.