Effects of Ageing on Amylase Activity and Scutellar Cell Structure during Imbibition in Wheat Seed

In wheat seed the scutellum plays an important role in the hydrolysis of stored substrate during germination. This layer is activated first, whilst the aleurone becomes activated later. A good correlation exists between the initiation of visible germination and the appearance of enzyme activity in the scutellum. Enzyme activity in the aleurone becomes apparent only when the germinating seedling reaches the rapid growth phase. Electron microscopic observations show that during the later stages of germination the scutellar cells develop finger like projections. These may serve to absorb endospermic reserves hydrolysed by aleurone amylase. The scutellum of aged non-germinating seeds showed no amylase activity and no finger like projections were produced even after prolonged imbibition.