Properties of oil body development and characteristics of OLE gene in herbaceous peony (Paeoinia lactiflora Pall.) seeds

Oil bodies (OBs) are organelles of lipid storage in plants. In order to clarify the properties of OBs development in herbaceous peony (Paeonia lactiflora Pall.) seeds, this research had studied anatomical structures, particle size, zeta potential, the stability of OBs and characteristics of oleosin gene (OLE). It showed that OB particle size increased gradually during seed development, OBs accumulated in the endosperm cells, and their zeta potential firstly decreased and then increased. Temperature had not affected the stability of OBs, they could be maintained stably under the conditions of neutral and alkaline pH and less than 50 mM NaCl. Subsequently, P. lactiflora OLE was isolated, it had 824 bp in full-length and a 435-bp open reading frame encoding 144 amino acids with isoelectric point 9.40, which had three transmembrane domain and did not has a signal peptide, and belonged to the stable protein. Alpha helix was the main part of the secondary structure, no glycosylation site and 14 potential phosphorylation sites were found. Additionally, the express level of OLE initially increased and then decreased, and reached the highest on 60 days after flowering. These results could contribute to understand the properties of OBs development and characteristics of OLE in P. lactiflora seeds.