Protein, nucleic acids and enzyme levels during development in a high lysine sorghum grain

Abstract

Dry wt, protein, free amino-N, RNA, DNA and the levels of hydrolytic enzymes have been measured in high lysine and normal sorghum grain during development. Dry wt was higher in CSV-5 throughout development. Protein accumulation/grain was lower in the later stages of development of IS 11 758 than in CSV-5. The lower rate of protein accumulation in IS 11758 is not due to a limitation of free amino-N. CSV-5 had a higher proportion of prolamine. A major part of the prolamine in CSV-5 was deposited in a relatively short period from day 24 to 31. In this period much less prolamine was synthesized in IS 11758. RNA content was higher in IS 11758. DNA content, however, was higher in CSV-5 than IS 11758 during early stages of development. RNase activity at maturity was lower in IS 11758. Amylase activity/grain in both was similar, however, on a fr. wt basis it was higher in CSV-5. Protease level/grain was higher in IS 11758.