Hematin Compounds of Bean Seed Embryo in the Germination Stage

Abstract

The changes of peroxidase- and catalase-activity were investigated in each organ of bean seed embryo at the germination stage.
The peroxidase-activity was strongest in radicule. In plumule the activity was comparatively strong, while the activity in hypocotyl and epicotyl remained at a certain level through the germination stage.
In cotyledon and plumule, the catalase activities were the strongest. In axial organs it was shown to have a certain value. In radicule the activity was the weakest. The so-called enzymic organ-specificity was clearly shown in the feature that peroxidase was much in root and catalase was present in a large amount in leaf.
The change of the protohemin-content in each organ through the germination period was studied. The hemin-content in cotyledon was kept unchanged at a certain level throughout the germination period. The value of the level was higher than that found in other germinating organs. Each germinating organ of the seedling showed a steady (almost linear) increase in the hemin-content with the growth. This fact suggested that hemin was newly produced, functioning and acting in the growing plant tissues. Especially the plumule, despite it was small in size, contained hemin of a high concentration and exhibited the character of active organ at the germination-stage.
Each hemin amount of peroxidase and catalase was estimated from their activities, and the fractions of these hemin in the total hemin were compared and discussed.