Cytochemical localization and antigenicity of α-amylase in barley aleurone tissue.

Gibberellic-acid(GA3)-induced α-amylase has been localised in barley aleurone layers using cytochemical methods and light microscopy. Evidence obtained from the use of a starch substrate film method as well as immunofluorescence indicated that the first amylase to appear in the cell was associated with aleurone grains, apparently with the outer membrane, and also with the peripheral cytoplasm. In GA3-treated tissue, the amylase distribution was much more diffuse, although patchy, throughout the cytoplasm and it tended to accumulate in the endosperm side of the cell. The possibility that the aleurone grain membrane is the site of gibberellin-induced enzyme synthesis and that it proliferates to become rough endoplasmic reticulum is considered. Immunological information was obtained which supports earlier indications that induced α-amylase consists of two different proteins, each with molecular heterogeneity.