CHANGES OF LIPID, PROTEIN, RNA AND FATTY-ACID COMPOSITION IN DEVELOPING SESAME (SESAMUM-INDICUM L) SEEDS

During development of sesame oilseeds, changes in lipid, protein and RNA levels were scrutinized and discussed. In total lipid a rapid increase commenced at 15 days after flowering (DAF) and continued to 38 DAF. Thereafter a gradual rise was found and finally the lipid accumulated as storage lipid. In changes of protein a sudden increase was observed at 12 DAF, then the protein built up until the oilseeds matured completely and in general, the changing pattern of protein was coincident with that of lipid. In changes of RNA, between 12 DAF and 21 DAF, RNA increased remarkably and maximized at 21 DAF. After 21 DAF a gradual decrease was detected and reached minimum levels. Palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid consisted of over 98% of total lipid on the average and of them, oleic acid and linoleic acid were composed of about 80% of total fatty acids. In contrast the percent composition of the other three fatty acids showed a gradual decrease with slight fluctuations as the oilseeds develop, suggesting the major storage forms of fatty acids in sesame oilseeds would be oleic acid and linoleic acid. SDS-PAGE analysis exhibited that two polypeptides with 20 kD and 31-32 kD and one other polypeptide with 50 kD, appeared to be legumin-like storage protein and vicilin-like storaage proteins, respectively.