between GA3 addition and the start of a-amylase production (about 8 h in barley;
Fig. 8.1) have received much attention. Changes occur in the internal organiza-
tion of the aleurone layer cells during this period; e.g., at least 2 h before the lag
period is completed, the protein-storing aleurone grains lose their spherical
appearance and undergo distinct volume and shape changes. This is probably
because of the hydrolysis of the proteins within these grains to provide amino
acids for the de novo synthesis of a-amylase and other enzymes