Identification of the cytokinins in red pine seedlings

Abstract

Zeatin-9-riboside was identified in shoots and roots of Pinus resinosa by GC-MS analysis of its permethyl derivative. Based on their chromatographic properties on Sephadex LH-20 and C18 HPLC, and their susceptibility to enzymatic degradation, several other cytokinins have been tentatively identified. The basic fraction of both the roots and shoots contained zeatin, whereas the shoots contained dihydrozeatin-O-glucoside and the roots contained zeatin-O-glucoside. Zeatin-9-riboside monophosphate, isopentenyladenosine monophosphate ([9R-5′P]iP) and glucosyl phosphate derivatives were detected in the acidic fractions from both roots and shoots. There were equivalent amounts of [9R-5′P]iP in both roots and shoots. The presence of equivalent amounts of [9R-5′P]iP in both the roots and shots suggests that cytokinin biosynthesis may be occurring in both locations.