title: The occurrence of free and bound cytokinins in plasmodia of Plasmodiophora brassicae isolated from tissue cultures of clubroots.
abstract: Plasmodia have been isolated from Brassica campestris tissue infected with Plasmodiophora brassicae. Cytokinins were extracted from plasmodia and from the remaining host cytoplasm. Fractions were separated in a butanol soluble fraction containing free cytokinins and a water soluble fraction containing bound forms, presumably glucose-6-phosphate derivatives of zeatin and zeatin riboside. The butanol fraction was analysed by high pressure liquid chromatography (HPLC). The different glucosides were determined after treatment of the water fraction with β-glucosidase.Plasmodia contained zeatin riboside and its glucose derivative (175 and 1600 ng/g dry weight, respectively). Host cytoplasm contained zeatin riboside (132 ng/g dry weight) and small amounts of the glucose-6-phosphate derivatives of zeatin and zeatin riboside. The results suggest that plasmodia synthesize cytokinins which are released into the host cytoplasm inducing host cell division.
authors.affiliation: Centre of Agrobiological Research, Postbox 14, NL-6700 AA, Wageningen, The Netherlands.
authors.forename: H M
authors.initials: HM
authors.lastname: Dekhuijzen