DISTRIBUTION AND DEVELOPMENT OF ENDO-β-GLUCANASE ACTIVITIES IN BARLEY TISSUES DURING GERMINATION

Abstract

Extracts of barley (Hordeum vulgare L.) tissues were assayed for endo-β1,4-glucanase, endo-β1,3-glucanase and barley-β-glucan endo-hydrolase activities. The seven tissues examined were-hull, pericarp, green layer, aleurone, endosperm, embryo and scutellum. Tissues were dissected from unsteeped barley kernels and from kernels at various stages of germination. Endo-β1,4-glucanase activity occurred primarily in the hull and pericarp tissues but was also present in the endosperm during late germination. Endo-β1,3-glucanase activity was located predominantly in the embryo and scutellum of unsteeped kernels. During germination, this activity increased markedly in the aleurone and endosperm. Barley-β-glucan endo-hydrolase activity was concentrated in the aleurone and endosperm and small amounts were found in the hull, embryo and scutellum. Analyses of extracts from hull and endosperm tissues by column chromatography with CM-cellulose indicated that both tissues contain two similar enzymes with barley-β-glucan endo-hydrolase activity.