ANATOMICAL DISTRIBUTION OF PEROXIDASE ISOZYMES IN BARLEY KERNELS

Two barley (Hordeum vulgare L.) cultivars with different peroxidase isozyme patterns were studied using polyacrylamide-slab electrophoresis at pH 4.75 to separate the enzymes, and 3-amino-9-ethyl carbazole or o-dianisidine as hydrogen donors to detect peroxidase isozymes. Peroxidase isozyme patterns of extracts of very immature kernels up to 19 days post-anthesis were quite different from isozyme patterns from extracts of more mature kernels. During malting, the peroxidase isozymes of mature barely persisted in green malt, but an additional isozyme was detected in malt after 3 days of germination. Immature kernels with peroxidase isozyme patterns identical to those found in mature kernels for each barley cultivar were dissected into different tissue fractions including husks, pericarp, "green layer," aleurone, endosperm, embryo and scutellum. Electrophoresis of extracts of these tissues revealed the anatomical location of most of the peroxidase enzymes in the whole kernels of the two cultivars.