The Occurrence and Development of Amylase Enzymes in Incubated, De-embryonated Maize Kernels

The development of amylase activity in extracts from de-embryonated and GA(3)-treated de-embryonated maize kernels (Zea mays L.) was determined during a 10-day incubation period. The increase in activity was compared with activity extracted from endosperms dissected from germinating whole kernels. Chromatographic analysis of reaction products as well as physicochemical characterization demonstrated that the activities from GA(3)-treated and nontreated tissue were comparable and that part of the activity was attributable to alpha-amylase.Concomitant with the increase in activity was the appearance of a number of starch-degrading bands, as evidenced by polyacrylamide gel electrophoresis. Actinomycin-D (20 mug/ml) and cycloheximide (5 mug/ml), when present in the incubation medium at early periods of incubation, were capable of inhibiting the development of amylase activity and of preventing the appearance of the starch-degrading bands.The results indicate that the development of alpha-amylase activity in de-embryonated maize kernels is independent of an embryo or an exogenous source of gibberellic acid and suggest that this process involved protein synthesis.