Abstract: To comprehensively analyze the genetic information ofPenicillium oxalicumSG-4, a combination of second-generation Illumina sequencing and third-generation PacBio sequencing was employed to sequence the complete genome of the SG-4 strain. Following genome assembly, gene prediction, and functional annotation, collinearity analysis was conducted on the whole genome and the gene clusters involved in secondary metabolite synthesis were predicted. The results showed that the genome size of SG-4 was 31.17 Mb, consisting of 9 scaffolds (including mitochondria), with GC content of 50.5%, and encompassing 8430 protein-coding genes along with 175 tRNA genes and 50 rRNA genes. Compared with the databases of swiss-prot, Pfam, NR, GO, and KEGG, the COG database annotated the largest number of genes to up to 7483. Through bioinformatics analysis, a total of 28 biosynthesis gene clusters of secondary metabolites were identified in the SG-4 genome, with 14 gene clusters having unknown functions. By correlating NRPS-related gene clusters with transcriptome data, the relationship between these gene clusters and the trend of Sanxiapeptin synthesis was analyzed, resulting in identification of 9 relevant gene clusters. Among them, one particular gene cluster might be a potential candidate responsible for Sanxiapeptin synthesis. This study enhanced our understanding ofP. oxalicum’s genomic information, laying a foundation for comprehensive characteristics as well as revealing the biosynthesis pathway of Sanxiapeptin.

Key words: Penicillium oxalicum, SG-4, genome, gene annotation, Sanxiapeptin