Cereal Chem 60:27 - 31. | VIEW
Endosperm Modification in Germinating Sorghum Grain.
C. W. Glennie, J. Harris, and N. V. D. W. Liebenberg. Copyright 1983 by the American Association of Cereal Chemists, Inc.
Several techniques were used to prepare germinated sorghum grains for both transmission and scanning electron microscopy and, hence, to study the patterns of modification that occurred in the endosperm during germination. Bird-resistant sorghum grain was germinated on moist filter paper at 28 C for 12 days, and samples were taken every day for microscopic examination. Endosperm modification began at the endosperm scutellum interface and subsequently moved into the floury endosperm, with slight modification of the peripheral endosperm. The horny endosperm was modified last. The matrix protein began to disappear first, and after it was disrupted, the starch granules and protein bodies were degraded simultaneously. The starch granules were modified by pitting rather than by surface erosion, and their interiors soon became hollow. Viewed from the outside, their form still remained. The aleurone cells did not appear to be active in enzyme production; rather the scutellum fulfilled this role. However, the aleurone cells were extensively modified during germination, and their mineral content was greatly reduced. The cell walls were the only part of the endosperm that appeared visually unchanged after germination; they retained their structure even after the endosperm was extensively modified and the cells had lost their contents.