Abstract：Oleosins are a type of small and basic protein covering the surface of oil body. Oleosin plays an important role in oil body stabilization and is often used as carrier for production of recombinant proteins in plants. The full length cDNA library of cultivated peanut(Arachis hypogaea L.) Luhua14 seeds was constructed and sequenced. From cDNA library we found 284 oleosin ESTs which could be classified into six groups, namely, AhOLEO-16.9，AhOLEO-17.7，AhOLEO-18.6，AhOLEO-22，AhOLEO-18.4 and AhOLEO-14.32 according to molecular weight of their coding proteins(GenBank Accession No: EG372527、EG373122, EG373716, EG372719, EE125019 and EE124234), in which AhOLEO-16.9，AhOLEO-17.7 and AhOLEO-14.3 family contained two members, the others contained one member, respectively, And the higher molecular weight oil oleosin gene AhOLEO-22 was first cloned in peanut. Peanut cDNA microarray and semi-quantitative RT-PCR results showed that the expression patterns of these six sub-family oleosin genes were similar in different organs and in seeds during different developmental stages. The expression of oleosin genes was very high in seed, while the expression of these genes was not detected in stems, leaves, flowers and roots. During seed development, the expression level of oleosin genes was low in DAP15 and gradually increased afterward. This research provides useful information for the study of peanut oleosin gene family as well as using of oleosin to improve peanut oil content and to produce foreign proteins.
