Activities of Transaminases, Amylases and Proteases during Endosperm Degradation in Normal and Opaque-2 Zea mays L. cv. Maya

Transaminase, amylase and protease activities were comparedin seedlings of normal and Opaque-2 (o2) maize. Transaminaseactivity, greater in normal maize, was highest in the scutellumfrom which it decreased rapidly in activity from day 2 afterimbibition; only low activity was observed in endosperm andaxis tissue. Amylolytic activity, optimal around pH 5, was greater in normalmaize at all stages of endosperm degradation. Activity whichwas low on day 2, rose to a peak on day 6 and declined afterwards.The level of free sugars in the endosperm of normal was higherthan in o2 maize, and in both varieties was highly correlatedwith amylolysis. Protease activity, optimal at pH 3.6, was also greater in normalendosperms and increased up to day 6 and activity was maintainedat this level until around day 14. Although the activity ofall three enzyme systems examined was greater in normal maizethere were no apparent differences in the overall growth ofnormal and o2 seedlings during this period. Zea mays L, maize, corn, endosperm, enzyme activity, transaminase, amylase, protease