Characterization and Genome Analysis of Mycocentrospora acerina, the Causal Agent of Panax notoginseng Round Spot Disease in China

The pathogenic fungus <i>Mycocentrospora acerina</i>, responsible for <i>Panax notoginseng</i> round spot disease, poses a serious threat to the development of the <i>P. notoginseng</i> industry. To investigate its genetic information and potential pathogenic mechanisms, this study employed nanopore third-generation sequencing technology to conduct de novo genome sequencing and analysis of <i>M. acerina</i>, followed by an assessment of its plant cell wall-degrading enzyme activities. The sequencing results revealed that the <i>M. acerina</i> genome has a total length of 37.03 Mb, a GC content of 47.68%, an N50 value of 1.66 Mb, and a repeat sequence proportion of 9.37%. A total of 9989 protein-coding genes were predicted. Genome annotation identified 499 carbohydrate-active enzyme (CAZyme) family genes-more than those found in <i>Botrytis cinerea</i> (469), <i>Phanerochaete chrysosporium</i> (381), and <i>Erysiphe necator</i> (136). Moreover, <i>M. acerina</i> harbors a relatively large number of genes encoding plant cell wall-degrading enzymes. Experimental measurements of cell wall-degrading enzyme activities were consistent with the genomic predictions, demonstrating that <i>M. acerina</i> exhibits strong abilities to degrade cellulose, pectin, and lignin. This study provides new insights into the pathogenic mechanisms of <i>M. acerina</i> and establishes a theoretical foundation for developing potential control strategies for <i>P. notoginseng</i> round spot disease.