Whole genome sequencing of Clarireedia aff. paspali reveals potential pathogenesis factors in Clarireedia species, causal agents of dollar spot in turfgrass.

Dollar spot is one of the most damaging diseases in turfgrass, reducing its quality and playability. Two species, and (formerly ) have been reported so far in the United States To study the genome, two isolates H2 and H3, sampled from seashore paspalum in Hawaii in 2019 were sequenced Illumina paired-end sequencing by synthesis technology and PacBio SMRT sequencing. Both isolates were identified as . aff. , a novel species in the United States Using short and long reads, . aff. H3 contained 193 contigs with 48.6 Mbp and presented the most completed assembly and annotation among species. Out of the 13,428 protein models from AUGUSTUS, 349 cytoplasmic effectors and 13 apoplastic effectors were identified by EffectorP. To further decipher pathogenicity, . aff. genomes (H2 and H3), as well as available (LWC-10 and HRI11), (DRR09 and RB-19) genomes were screened for fifty-four pathogenesis determinants, previously identified in . Seventeen orthologs of pathogenicity genes have been identified in species involved in oxalic acid production (, ), mitogen-activated protein kinase cascade (, , ), appressorium formation (, , , , ) and glycolytic pathway (). Within these genes, 366 species-specific SNPs were recorded between species; twenty-eight were non-synonymous and non-conservative. The predicted protein structure of six of these genes showed superimposition of the models among spp. The genomic variations revealed here could potentially lead to differences in pathogenesis and other physiological functions among species.