Variation of the Levels and Transport of Cytokinins during Germination of Chick-pea Seeds

Abstract

Summary Cytokinins detected in chick-pea seeds were present in the embryonic axes and first appeared in the cotyledons after 12 hours of germination. The appearance and initial increase of cytokinins in cotyledons is common to both the free and bound forms. However, from 24 hours of germination onwards the disappearance of bound cytokinins is much faster than that of the free forms, suggesting transformation of the bound forms into free ones during this stage of germination. The cytokinins detected in the cotyledons seem to originate from the embryonic axes, though there is no passage of these substances from the cotyledons to the axes. The β-glucosidase activity measured both in cotyledons and in embryonic axes, was seen to be positively correlated with the decrease in bound cytokinins and the increase in free forms, suggesting the transformation of cytokinin glycosides into their corresponding free forms.