1. Aleurone layer. Proteinases are produced in the aleurone layer, in some species or cultivars under the control of gibberellin (see Section 8.1.5), and these may be synthesized de novo. One or more of these enzymes hydrolyzes the proteins within the aleurone grains, and the resultant amino acids are utilized for the synthesis of proteins (e.g., a-amylase) in this tissue.