Whole Genome Identification and Biochemical Characteristics of the Tilletia horrida Cytochrome P450 Gene Family

Abstract: Rice kernel smut caused by the biotrophic basidiomycete fungus Tilletia horrida causes significant yield losses in hybrid rice-growing areas around the world. Cytochrome P450 (CYP) enzyme is a membrane-bound heme-containing monooxygenase. In fungi, CYPs play a role in cellular metabolism, adaptation, pathogenicity, decomposition, and biotransformation of hazardous chemicals. In this study, we identified 20 CYP genes based on complete sequence analysis and functional annotation from the T. horrida JY-521 genome. The subcellular localization, conserved motifs, and structures of these 20 CYP genes were further predicted. The ThCYP genes exhibit differences in gene structures and protein motifs. Subcellular localization showed that they were located in the plasma membrane, cytoplasm, nucleus, mitochondria, and extracellular space, indicating that they had multiple functions. Some cis-regulatory elements related to stress response and plant hormones were found in the promoter regions of these genes. Protein–protein interaction (PPI) analysis showed that several ThCYP proteins interact with multiple proteins involved in the ergosterol pathway. Moreover, the expression of 20 CYP genes had different responses to different infection time points and underwent dynamic changes during T. horrida JY-521 infection, indicating that these genes were involved in the interaction with rice and their potential role in the pathogenic mechanism. These results provided valuable resources for elucidating the structure of T. horrida CYP family proteins and laid an important foundation for further research of their roles in the pathogenesis.