Cytokinins as Endogenous Growth Regulators in the Algae Ecklonia (Phaeophyta) and Hypnea (Rhodophyta)

Abstract

Cytokinin activity was detected in extracts prepared from Ecklonia radiata (Phaeophyta) and Hypnea musciformis (Rhodophyta), and was associated with chromatogram bands which appeared to contain purine. Kinetin, a cytokinin with a purine ring system, stimulated growth in cultured plants of the same species. It is concluded that cytokinins are normally involved in regulating growth in these algae. On the basis of this and other evidence, it is suggested that plant growth regulators of the auxin, gibberellin, and cytokinin type may have arisen early in plant evolution.