De novo assembly of the peanut (Arachis hypogaea L.) seed transcriptome revealed candidate unigenes for oil accumulation pathways.

Peanuts are one of the most important edible oil crops in the world. In order to survey key genes controlling peanut oil accumulation, we analyzed the seed transcriptome in different developmental stages of high- and low-oil peanut varieties. About 54 million high quality clean reads were generated, which corresponded to 4.85 Gb total nucleotides. These reads were assembled into 59,236 unique sequences. Differential mRNA processing events were detected for most of the peanut Unigenes and found that 15.8% and 18.0% of the Unigenes were differentially expressed between high- and low-oil varieties at 30 DAF and 50 DAF, respectively. Over 1,500 Unigenes involved in lipid metabolism were identified, classified, and found to participate in FA synthesis and TAG assembly. There were seven possible metabolic pathways involved in the accumulation of oil during seed development. This dataset provides more sequence resource for peanut plant and will serve as the foundation to understand the mechanisms of oil accumulation in oil crops.