Characterization of the CBM50 Gene Family in Tilletia horrida and Identification of the Putative Effector Gene ThCBM50_1

Carbohydrate-binding modules (CBMs) are essential virulence factors in phytopathogens, particularly the extensively studied members from the CBM50 gene family, which are known as lysin motif (LysM) effectors and which play crucial roles in plant-pathogen interactions. However, the function of CBM50 in <i>Tilletia horrida</i> has yet to be fully studied. In this study, we identified seven CBM50 genes from the <i>T. horrida</i> genome through complete sequence analysis and functional annotation. Their phylogenetic relationships, conserved motifs, promoter elements, and expression profile were further analyzed. The phylogenetic analysis indicated that these seven ThCBM50 genes were divided into three groups, and close associations were observed among proteins with similar protein motifs. The promoter cis-acting elements analysis revealed that these ThCBM50 proteins may be involved in the regulation of the phytohormones, stress response, and meristem expression of the host plant during <i>T. horrida</i> infection. The transcriptome data indicated that four ThCBM50 genes were upregulated during <i>T. horrida</i> infection. We further found that <i>ThCBM50_1</i> caused cell death in the leaves of <i>Nicotiana benthamiana</i>, and its signal peptide (SP) had a secreting function. These results offer important clues that highlight the features of <i>T. horrida</i> CBM50 family proteins and set the stage for further investigation into their roles in the interactions between <i>T. horrida</i> and rice.