Metabolic Changes Associated with the Germination of Corn. I. Changes in Weight and Metabolites and their Redistribution in the Embryo Axis, Scutellum, and Endosperm.

There is a paucity of information in the literature concerning the metabolic changes that occur in the endosperm, scutellum, and embryonic axis during the germination of corn. The work of Toole (20) constitutes a major exception, although this work was more concerned with morphological changes during germination than with changes in chemical constituents and metabolism. Although seed germination has been studied extensively (3, 13, 21) much of the work has been concerned with changes in the whole seed, which may obscure changes occurring in the embryo or embryonic parts. In other instances work has been conducted with an isolated organ or tissue, or has been concerned with a single constituent, or with a particular class of enzymes. In recent years major emphasis has been placed on the effect of light, inhibitors, or dormancy on germination. This investigation was prompted by the lack of data on the time sequence of metabolic changes, an-the interrelationship of these changes in the en losperm, scutellum, and embryonic axis of germinating corn. Furthermore it was hoped that the results obtained would serve as a standard for further studies concernel with applied treatments. The changes in fresh and dry weight, nitrogen fractions, sugars, fats, and nucleic acids which occur in the endosperm, scutellum, and embryonic axis during a 5-day period of germination are presented. These changes are discussed in relation to the role of the endosperm and scutellum in supplying metabolic components to the developing embryo axis.