Global Transcriptome Analyses Provide Into Several Fatty Acid Biosynthesis-related Genes in Peanut (Arachis hypogaea L.)

Peanut (Arachis hypogaea L.) is one of the important oil crops worldwide. Revealing the molecular basis of seed oil synthesis and analyzing key candidate genes may have important implications for enhancing peanut production. In this study, we investigated the dynamic changes in the oil accumulation rate and gene expression levels in developing peanut seeds. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the up-regulated differentially expressed genes (DEGs) among three varieties at 25–35 days after flowering (DAF) were involved in fatty acid synthesis, carbon metabolism, and pyruvate metabolism. Between 25 and 35 DAF, the up-regulated DEGs in the high-oil varieties, but not in the low-oil variety, were related to acetyl-CoA synthesis. We examined the differences in the varieties at the same stages. We analyzed the lipid metabolism-related genes by protein–protein interaction (PPI), and finally identified 57 DEGs that may influence the peanut oil content. These candidate genes included three genes encoding acetyl-CoA carboxylase (ACCase), one gene encoding ketoacyl-ACP synthase III (KASIII), one gene encoding hydroxyacyl-ACP dehydrase (HAD), and one gene encoding enoyl-ACP reductase (EAR), which form the Type II fatty acid synthase complex. Additionally, we also found that 11 transcription factors may affect oil content. These identified candidate genes may help to further clarify the molecular basis of the oil accumulation in peanut seeds.