Whole-genome mining and in silico analysis of FAD gene family in Brassica juncea

Brassica juncea is one of important oilseed crops, and FA compositions determine quality of vegetable oil. Although fatty acid desaturases (FADs) are mainly responsible for modifying seed FA compositions, genome-wide analysis of FAD gene family in B. juncea ( BjuFAD ) is not reported. Here, we identified 57 BjuFAD genes in B. juncea genome using homology searches. These FAD genes were unevenly distributed in 16 chromosomes and 3 scaffolds. Phylogenetic analysis showed that BjuFAD genes were divided into seven subfamilies. Exon–intron organizations, intron patterns and MEME motifs were highly conserved within each of BjuFAD subfamilies. Moreover, subcellular locations of deduced BjuFAD proteins and cis -acting elements in BjuFAD promoters were predicted and analyzed using online software. In addition, 16 SSR loci were totally found in BjuFAD genes/promoters. This work provides a basis for further function study of BjuFAD genes in quality improvement of B. juncea seed oil and in plant development as well as stress response.