First draft genome and transcriptome of Cercosporidium personatum, causal agent of late leaf spot disease of peanut

Authors: Arias De Ares, Renee; DOBBS, JOHN - Colorado State University; STEWART, JANE - Colorado State University; CANTONWINE, EMILY - Valdosta State University; Orner, Valerie; Sobolev, Victor; Lamb, Marshall; Massa, Alicia

Submitted to: BMC Research Notes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2023
Publication Date: 4/21/2023
Citation: Arias De Ares, R.S., Dobbs, J., Stewart, J., Cantonwine, E., Orner, V.A., Sobolev, V., Lamb, M.C., Massa, A.N. 2023. First draft genome and transcriptome of Cercosporidium personatum, causal agent of late leaf spot disease of peanut. BMC Research Notes. 16:58. https://doi.org/10.1186/s13104-023-06331-0.

Interpretive Summary: The fungus Cercorsporidium personatum causal agent of late leaf spot disease in peanut, causes peanut farmers millions in losses each year. Efforts in peanut genetic improvement by searching for resistant germplasm, are hindered due to the lack of genetic information of the pathogen that causes the disease. In the laboratory the fungus grows extremely slow, making colonies no larger than 1 cm diameter in six months, in addition, extracting nucleic acids from this fungus to achieve genome sequencing is very challenging too. In this work we report the the first genome assembly of the fungus as well as a description of the genes found in its genome. Together, the information will allow research on the fungus and its interaction with peanut plants.

Technical Abstract: Objective: Two main fungal leaf spot diseases occur in peanut, namely early leaf spot (ELS) and late leaf spot (LLS), together they cause a yearly average of $44 million losses. Limited genetic information exists, only 3534 bp of sequencing, about the causal agent of LLS, Cercosporidium personatum, Syn Nothopassalora personata, Syn. Phaeoisariopsis personata. The extremely slow growth of this fungus, approximately 1 cm diameter colony in six months, and challenges in nucleic acid extractions have hindered research on LLS. Our goal in this work is to provide a reference genome for research on this pathogen. Results: Whole genome and transcriptome sequencing of the LLS fungus were obtained. A total of 233,542,110 reads of the genome were de novo assembled resulting in 1,061 scaffolds, and estimated genome size 27,597,787 bp. RNA sequencing resulted in 11,848,198 reads that were de novo assembled into 13,343 contigs. Genome annotation resulted in 10,703 putative genes. BUSCO completeness of the genome and annotation resulted in 91.1 % and 89.5 % completeness, respectively. Phylogenetic dendrograms for 5442 bp and 4401 bp of RNA Polymerase II largest and second largest subunits, and for 5474 bp of the ribosomal RNA cistron of C. personatum are presented in relation to closely related fungi.