Genomic and Functional Analysis of Auxiliary Activity Enzymes in the Maize Anthracnose Pathogen Colletotrichum graminicola

Colletotrichum graminicola, the causative agent of maize anthracnose leaf blight and stalk rot, severely jeopardizes the healthy development of the maize industry. Auxiliary activity enzymes (AAs), a vital subclass of carbohydrate-active enzymes, act as beneficial accessory proteins for fungi in degrading lignocellulose. This study identified 127 AA genes from the genome of C. graminicola strain TZ-3 and further analyzed the subcellular localization, conserved motifs, and domains of the proteins encoded by these genes. The CgAA genes exhibited significant variations in gene structure, and the structural motifs within their encoded proteins also differed. Subcellular localization analysis revealed that most CgAA proteins were localized in the extracellular space. Moreover, the CgAA gene family contained abundant conserved domains, suggesting diverse functionalities and potential roles in various fungal biological processes. Multiple cis-acting regulatory elements related to stress responses and plant hormones were detected in the promoter regions of these genes. This study analyzed the expression patterns of CgAA genes during pathogen–host interactions and found that most CgAA genes were differentially expressed in the interaction between C. graminicola and maize. Coupled with GO functional analysis, it was discovered that CgAAs are deeply involved in the interaction between C. graminicola and maize, closely associated with the pathogenic mechanisms of the pathogen, and may play crucial roles in the initiation and expansion of fungal infections. These results provide valuable resources for elucidating the functions of AA genes and lay the groundwork for sustainable agricultural development through the utilization of AA genes in disease control and the breeding of stress-resistant, high-yield crop varieties.