Genome-Wide Identification and Analysis of Carbohydrate-Binding Modules in Colletotrichum graminicola

Colletotrichum graminicola is the causative agent of both maize stem rot and leaf blight, which are among the most damaging diseases affecting maize. Carbohydrate-binding modules (CBMs) are protein domains that lack catalytic activity and are commonly found alongside carbohydrate-hydrolyzing enzymes in fungi. A comprehensive examination of the C. graminicola TZ-3 genome resulted in the identification of 83 C. graminicola CBM (CgCBM) genes, which are characterized by distinct gene structures and protein motifs. Subcellular localization analysis revealed that the majority of CgCBM proteins were localized in the extracellular space. Investigation of the promoter regions of CgCBM genes uncovered a variety of responsive elements associated with plant hormones, including abscisic acid and methyl jasmonate response elements, as well as various stress-related response elements for drought, cold, defense, and other stress factors. Gene ontology analysis identified the primary functions of CgCBM genes as being linked to polysaccharide metabolism processes. Furthermore, the 83 CgCBM genes exhibited varying responses at different time points during C. graminicola infection, indicating their contribution to the fungus-maize interaction and their potential roles in the fungal pathogenic process. This study provides essential insights into CgCBMs, establishing a crucial foundation for further exploration of their functions in the mechanisms of fungal pathogenicity.