Changes in Levels of alpha-Amylase Components in Barley Tissues during Germination and Early Seedling Growth

Kernels of Klages barley (Hordeum vulgare L.) were germinated for 1 to 4 days on moist sand at 18 degrees C. Representative kernels from each time period were dissected to give the following fractions: scutellum, subscutellar endosperm, aleurone-scutellum interface, remaining aleurone, subaleurone endosperm, and core endosperm. These tissues were analyzed for alpha-amylase components by isoelectric focusing and rocket-line immunoelectrophoresis. Although aleurone and scutellar tissues appeared to synthesize the same alpha-amylase components, enzyme was detected first in the scutellum. A larger proportion of scutellar alpha-amylase was excreted into the endosperm compared to aleurone synthesized alpha-amylase. Aleurone cells appeared to synthesize appreciably more alpha-amylase than did scutellar tissue.