Cytochrome P450 monooxygenases (CYPs) have essential roles in the biosynthesis of secondary metabolites via participating in diverse biochemical pathways. However, the biological functions of the majority of potato StCYP genes remain unknown. At present study, we performed a comprehensive genome-wide analysis of CYP genes in Solanum tuberosum genome, a sum of 563 StCYP genes was identified and classified into 9 clans and 46 subfamilies. Four typical conserved motifs of CYP proteins were widely distributed in the members of potato CYP gene family. Collinearity analysis elucidated 38 and 251 gene pairs of segmental and tandem duplications distributed in potato genome, respectively. Cis-acting elements analysis indicated that StCYP genes are involved in diverse hormone regulation and stress responses. RNA-seq data revealed that StCYP genes were widely and differentially expressed in various tissues. In addition, a total of 69 and 21 StCYP genes consistently up- and down-regulated under salt treatment were identified, respectively, indicating that these genes are involved in regulating salt tolerance. Among the identified candidates, StCYP481 was selected as a candidate gene due to its significant salt-induced expression profile and the presence of conserved salt-responsive cis-elements in its promoter region. Transient expression assays in tobacco revealed enhanced promoter activity of the StCYP481 gene under salt stress conditions. Heterologous expression in Arabidopsis confirmed that the StCYP481 gene significantly mediates salt stress responsiveness and enhances tolerance by maintaining photosynthetic capacity, increasing compatible osmolytes biosynthesis and reducing ROS accumulation. These findings provide the first experimental evidence for CYP-mediated salinity adaptation in potato and a molecular framework for improving potato salt tolerance.
Hou et al. (Mon,) studied this question.