Genomic analysis for Biosynthesis and Metabolic Pathway of Elsinochrome Toxin produced by Elsinoë arachidis

Abstract

Background: Elsinoë arachidis, an important peanut pathogenic fungus that distributes widely and leads to large-scale losses in peanut producing regions in China, produce elsinochromes (ESCs) as the vital toxin through pathogenic process. However, the biosynthesis of elsinochromes have not been investigated and the transcriptional response of the light on synthesis of elsinochrome in Elsinoë is poorly understood. Results: In this paper, high-quality genome of E. arachidis by PacBio RS II sequencing method was reported. The 33.18Mb genome encodes 9056 predicted genes, of which the proportion of genes encoding secreted proteins 8.0% (734 secreted proteins), 124 transporter-related genes, 949 signal peptides, 1,829 transmembrane protein-coding genes, 127 non-coding RNAs and 13 pseudogenes. Mapped the E. arachidis assembly to 16 scaffold that contain 86 secondary metabolites gene clusters, including six polyketide synthase gene clusters encoding two melanin, one elsinochromes and three T-toxin were also identified in the genome. Additionally, ESC biosynthesis-related gene cluster predicted to contain ESCB1 which was high expression under light condition. Conclusion: Analysis of genomic information of E. arachidis lays a solid molecular data foundation for further exploration of pathogenic mechanisms and toxin biosynthesis pathways. Taken together, we provide a valuable foundation in the biosynthesis of elsinochrome and essential information for further comprehend its virulence mechanism.