Genomic Identification of CYP450 Enzymes and New Insights into Their Response to Diverse Abiotic Stresses in Brassica napus

Cytochrome P450 (CYP450) proteins are a large group of monooxygenase that play important roles in the biosynthesis of secondary metabolites and degradation of xenobiotics. However, the responses of CYP450 family to abiotic stresses have not been characterized in Brassica napus (B. napus). In this study, we identified a total of 384 CYP450 genes in Darmor-bzh, the rapeseed culture whose genome was wildly used as a reference for gene clone. The structure and localization analyses showed that BnaCYP450 genes have integrated heme-binding motif, contain 1–10 exons, unevenly distributed across all the 19 chromosomes, and mainly localized on chloroplast. Cis-regulation element analysis suggested that BnaCYP450 genes were transcriptionally regulated by hormone and multiple stress response signals. Transcript expression analyses identified 108, 85, 96, and 86 BnaCYP450s differentially expressed genes (DEGs) in response to salt stress, potassium deficiency, nitrogen stress, and cadmium toxicity, respectively. Gene ontology (GO) enrichment analysis indicated that these BnaCYP450 DEGs mainly enriched in molecular function of ion binding and oxidoreductase activity and the biological process of secondary product metabolism. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that they mainly involved in the pathway of isoflavonoid biosynthesis. Differential expression of BnaCYP450s to multiple abiotic stresses revealed the functional diversity of BnaCYP450 family in B. napus. This study gave a basic understanding of CYP450 genes in B. napus and provides multiple core BnaCYP450 genetic resources for improving plant resistance to multiple abiotic stresses.