Anthocyanin Formation in Excised Segments of Buckwheat-Seedling Hypocotyls

Recent studies of anthocyanin formation have involved the use of a varied assortment of plant systems: seedlings, leaves, fruits, petals, callus cultures, and Lemnaceous flowering plants (2, 9). Each of these kinds of material possesses certain advantages and certain disadvantages. In the dark-grown buckwheat seedling anthocyanin synthesis can be induced in the hypocotyl by exposure of that organ to light (6, 8); this formation of pigment is not accompanied by photosynthesis, since the hypocotyl does not contain chlorophyll. However, under many conditions which might be used in a study of anthocyanin formation, growth of the seedling, especially of the hypocotyl itself, would be a complicating factor. Furthermore, the hypocotyl is not homogeneous from top to bottom in its anthocyanin-forming capacity (1, 6). These disadvantages might be overcome by removing the hypocotyl from the seedling before its experimental use. Accordingly, an investigation of anthocyanin formation in excised hypocotyls and hypocotyl segments was undertaken in order to ascertain the suitability of such a system.