Genome-wide identification, evolution analysis of cytochrome P450 monooxygenase multigene family and their expression patterns during the early somatic embryogenesis in Dimocarpus longan Lour

Cytochrome P450 (CYP), a multi-gene superfamily, is involved in a broad range of physiological processes, including hormone responses and secondary metabolism throughout the plant life cycle. Longan (Dimocarpus longan), a subtropical and tropical evergreen fruit tree, its embryonic development is closely related to the yield and quality of fruits. And a large number of secondary metabolites, such as flavonoids and carotenoids, are also produced during the longan somatic embryogenesis (SE). It is important, therefore, to study potential functions of CYPs in longan. However, the knowledge of longan CYPs is still very limited. Here, a total of 327 DlCYPs were identified using the genome-search method, which could be classified into nine clans. The expansion of the DlCYP family was mainly caused by tandem duplication (TD) events. Promoter cis-acting elements analysis elucidated that DlCYPs played important roles in hormonal responses. A total of 246 DlCYPs exhibited six different expression patterns during the early SE based on longan transcriptomic data. Eight DlCYPs underwent alternative splicing (AS) events, and they might produce one to six isoforms. And the AS transcript of DlCYP97C1 might act as an alternative to the full-length transcript in ICpEC and GE stages. Finally, protein-protein interaction (PPI) networks and miRNA target prediction elucidated that DlCYPs might be involved in the phenylpropanoid metabolic pathway and primarily regulated and targeted by miR413. In summary, our results provided valuable inventory for understanding the classification and biological functions of DlCYPs and provided insight into further functional verification of DlCYPs during the longan early SE.