Comprehensive analysis and expression characterization of potato Cytochrome P450 gene family and the role of StCYP67 in abiotic stresses.

BACKGROUND

Brassinosteroids (BRs) play crucial roles in regulating developmental programming and activating stress-responsive networks under abiotic stress conditions. Members of cytochrome P450 monooxygenase (CYP450) superfamily have been reported to widely participate in the synthesis pathway of BRs in plants. However, the CYP450 superfamily needs to be systematically characterized at the whole-genome level in potatoes (Solanum tuberosum).

RESULTS

In this study, we identified 558 StCYP450 genes using data from the DM v6.1 potato genome database. These genes were classified into nine clans encompassing 44 families, with StCYP67 belonging to the CYP85 clan. Through bioinformatics analysis, we Mapped these genes across all 12 potato chromosomes and cell scaffolds. Phylogenetic reconstruction revealed that potato StCYP450 genes clustered into nine evolutionary groups, with distinct enrichment in groups I and IX compared to other species. Promoter analysis identified multiple cis-acting regulatory elements linked to phytohormone signaling (e.g., ABA, BRs) and abiotic stress adaptation. Expression profiling demonstrated differential regulation of StCYP450 genes under Cd²⁺, 24-epibrassinolide (EBL), and ABA treatments. Notably, overexpression of StCYP67 in potatoes significantly increased EBL content in transgenic potatoes (OE) compared with non-transgenic plants (NT), corroborated by RNA-seq data showing upregulation of BRs biosynthesis pathway genes. These findings strongly implicate StCYP450 proteins, particularly StCYP67, in mediating abiotic stress responses and BR synthesis in potatoes.

CONCLUSION

558 members of the StCYP450 family in potato were identified, many of which appear to participate in abiotic stress responses. Functional validation of StCYP67 highlights its dual role in BRs biosynthesis and stress regulation. These results not only clarify the evolutionary relationships within the StCYP450 gene family but also establish a foundation for future functional studies of these genes in potato.