Genome-Wide Identification, Evolutionary Patterns, and Expression Analysis of Gene Family in Olive ( L.).

Olive (.L) is an economically important oleaginous crop and its fruit cold-pressed oil is used for edible oil all over the world. The basic region-leucine zipper () family is one of the largest transcription factors families among eukaryotic organisms; its members play vital roles in environmental signaling, stress response, plant growth, seed maturation, and fruit development. However, a comprehensive report on the gene family in olive is lacking. In this study, 103 genes from the olive genome were identified and divided into 12 subfamilies according to their genetic relationship with 78 bZIPs of . Most genes are clustered in the subgroup that has a similar gene structure and conserved motif distribution. According to the characteristics of the leucine zipper region, the dimerization characteristics of 103 OebZIP proteins were predicted. Gene duplication analyses revealed that 22 genes were involved in the expansion of the family. To evaluate the expression patterns of genes, RNA-seq data available in public databases were analyzed. The highly expressed genes and several lipid synthesis genes () in fruits of two varieties with different oil contents during the fast oil accumulation stage were examined via qRT-PCR. By comparing the dynamic changes of oil accumulation, , , , and were shown to have a close relationship with fruit development and lipid synthesis. Additionally, some had a significant positive correlation with various genes. This study gives insights into the structural features, evolutionary patterns, and expression analysis, laying a foundation to further reveal the function of the 103 genes in olive.