Cytokinin metabolism in Phaseolus vulgaris L. : Identification of endogenous cytokinins and metabolism of [8-(14)C]dihydrozeatin in stems of decapitated plants.

Abstract

The major cytokinins in stems of decapitated, disbudded bean plants have been identified by enzymic degradation, Sephadex LH20 and reversed phase high performance liquid chromatography, and by combined gas chromatography-mass spectrometry as 6-(4-hydroxy-3-methylbut-trans-2-enylamino)-9-β-D-ribofuranosylpurine (zeatin riboside), 6-(4-hydroxy-3-methylbutylamino)-9-β-D-ribofuranosylpurine (dihydrozeatin riboside), and the 5'-phosphates of these compounds (zeatin ribotide and dihydrozeatin ribotide). Minor cytokinins in this tissue were tentatively identified as dihydrozeatin-O-β-D-glucoside and zeatin ribotide-O-β-D-glucoside. [8-(14)C-]Dihydrozeatin appeared to be rapidly metabolized to dihyd..