Carbon Catabolite Repressor UvCreA is Required for Development and Pathogenicity in Ustilaginoidea virens

The rice false smut disease, caused by Ustilaginoidea virens, has emerged as a significant global threat to rice production. The mechanism of carbon catabolite repression plays a crucial role in the efficient utilization of carbon nutrients and enzyme regulation in the presence of complex nutritional conditions. Although significant progress has been made in understanding carbon catabolite repression in fungi such as Aspergillus nidulans and Magnaporthe oryzae, its role in U. virens remains unclear. To address this knowledge gap, we identified UvCreA, a pivotal component of carbon catabolite repression, in U. virens. Our investigation revealed that UvCreA localized to the nucleus. Deletion of UvCreA resulted in decreased growth and pathogenicity in U. virens. Through RNA-seq analysis, it was found that the knockout of UvCreA led to the up-regulation of 514 genes and down-regulation of 640 genes. Moreover, UvCreA was found to be involved in the transcriptional regulation of pathogenic genes and genes associated with carbon metabolism in U. virens. In summary, our findings indicated that UvCreA is important in fungal development, virulence, and the utilization of carbon sources through transcriptional regulation, thus making it a critical element of carbon catabolite repression.