Sequence characterization and temporal expression analysis of different SADs and FAD2-2 genes in two Iranian olive cultivars

•OeSAD2 is suggested as the most pronounced isoform of stearoyl-acyl carrier protein desaturases responsible for oleic acid biosynthesis in olive mesocarp.•A number of nucleotide polymorphisms was detected along the sequences of important oil biosynthesis genes in different olive cultivars.•The in silico prediction of three-dimensional structure of FAD2-2 revealed a non cognate amino acid substitution which may led to the structural changes in the final protein structure and function.•OeFAD2-2 showed the highest sequence variability among olive cultivars and is suggested as a barcode for cultivar authentication, phylogenetic studies and clustering of olive cultivars.