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Botany and Microbiology Department, College of Science, King Saud University,

 P. 0. Box 2455, Riyadh-11451, Saudi Arabia 

ABSTRACT

The changes in fresh weight, dry weight, starch content, amylase and pullulanase activities and the electrophoretic protein and amylase pattern changes of cotyledons were studied during different days of germination. Cotyledon fresh weight increased linearly between 3 and 9 days, the dry weight declined rapidly between 1 and 3 days and linearly with time thereafter. Mature seeds contained 13.2 mg starch/g dry weight with starch levels increasing up to 23.3 mg/g dry weight by the third day post germination. Amylase and pullulanase activities increased linearly between 1 and 5 days. Mature seed extract resolved into one major band and two minor bands of amylase activity. The slowest migrating band disappeared at day 5 and a new band appeared at day 7 of germination. The analysis of protein by sodium-dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that protein patterns underwent marked changes in the third day, while the pattern of 1 day old Seedlings were almost identical to that of the ungerminated seeds. The two major subunits almost completely disappeared and three bands of lower molecular weight appeared in the extract. As germination progressed, the protein content of the larger subunits declined, and new minor bands appeared.