Characterization of Oil Bodies in Adlay (Coix lachryma-jobi L)

Abstract

Oil bodies were observed in cells of both embryo and aleurone layers of mature adlay grains (Coix lachryma-jobi L. var. ma-yuen Stapf). Stable oil bodies were successfully isolated from the adlay grains. Thin-layer chromatography revealed that the contents stored in the adlay oil bodies were mainly neutral lipids (>90% triacylglycerols and about 5% diacylglycerols). The integrity of the isolated oil bodies was presumably maintained via electronegative repulsion and steric hindrance provided by their surface proteins. Immunological cross-recognition using antibodies against sesame oil-body proteins indicated that two oleosin isoforms (termed oleosin-H and oleosin-L) and one caleosin were present in the adlay oil bodies. Full-length cDNA fragments encoding these three unique oil-body proteins were obtained by PCR cloning. MALDI-MS analyses confirmed that the three full-length cDNA fragments encoded the two oleosin isoforms and one caleosin observed in the oil bodies isolated from the adlay grains.