Identification of Cytokinins in Root Exudate of the Rice Plant

Cytokinins, cis-zeatin and cis- and (trans-ribosylzeatin, were identified in the root exudate of the rice plant (Oryza sativa, indica cultivar IR-24) after several chromatographic separations and combined gas-liquid chromatography-selected ion monitoring (GC-SIM) analysis. The presence of trans-zeatin ribotide was suggested by enzyme hydrolysis, subsequent chromatographic separation and GC-SIM. The comparatively high content of the ribotide in the root exudate suggests the form of cytokinins to be transported from roots to other parts in the rice plant.