Development of Ascorbate Oxidase Activity and Its Iso-enzyme Pattern in the Roots of Pea Seedlings

Early in the germination of peas, ascorbate Oxidase activity increased markedly in the root and epicotyl, but not in the cotyledons. The activity in the root was suppressed by the administration of 6-methylpurine, thiouracil, cyclohexi-mide, thioproline, and phenylthiourea. Although enzyme development was inhibited by phenylthiourea and thioproline, root elongation was not affected by these reagents. As germination progressed, the ascorbate oxidase activity in the extract of the seedling's root could be separated into at least 3 to 7 isoenzymes.