TRANSPORT OF [14C] GIBBERELLIC ACID IN THE BARLEY EMBRYO

Abstract

Radioactive gibberellic acid has been used to obtain direct evidence that, during germination of barley, transport occurs along vascular strands of the scutellum towards the dorsal (non-furrowed) surface of the grain. Preferential stimulation of the dorsally-placed aleurone cells therefore accounts for the normal asymmetric pattern of enzymic modification that occurs during malting. In the scutellum, gibberellic acid is transported at a rate of about 2.5 mm per hour. It is suggested that rapid development of the vascular system in the scutellum may be an important feature of barleys that malt rapidly.