CYTOKININ-INDUCED AMYLOLYTIC ACTIVITY IN BEAN COTYLEDONS - IDENTIFICATION OF THE REGULATED ENZYME

Separation of an extract of cotyledons of Phaseolus vulgaris on a column of Sephadex G-200 revealed three amylolytic fractions. The slower migrating fraction hydrolyzed/β-Limit dextrin azure and was inhibited by EDTA. The activity of this fraction was enhanced by the embryo axis and this effect could be fully replaced by kinetin or benzyladenine. These results suggest that the bean embryo axis exerts a promotive influence on the activity of a-amylase in the cotyledons and that this effect is mediated by cytokinins.The other two amylolytic fractions did not show a-amylase activity. No effect of the embryo axis or of cytokinins on their activity could be noted. © Oxford University Press.