# Diverse, novel mycoviruses coinfecting the phytopathogenic fungus Corynespora cassiicola from Sesamum indicum

## TL;DR

This study discovers 19 new mycoviruses in a fungus that causes sesame leaf disease, expanding knowledge of fungal viruses and their potential uses.

## Contribution

The study reports the first extensive catalog of mycoviruses in Corynespora cassiicola using metatranscriptomics.

## Key findings

- 19 mycoviruses were identified across seven fungal strains, spanning 12 viral families.
- The study reveals a high diversity of +ssRNA, −ssRNA, and dsRNA viruses in C. cassiicola.
- The findings provide a valuable resource for future research on mycovirus taxonomy and biocontrol potential.

## Abstract

Corynespora leaf spot caused by Corynespora cassiicola is one of the most serious foliar diseases of sesame. Mycoviruses can infect various groups of fungi and have certain potential biocontrol value. However, the number of mycovirus reported in C. cassiicola is relatively scarce.

Seven strains of C. cassiicola isolated from Sesamum indicum were subjected to metatranscriptomic sequencing. Viral diversity was further assessed and validated through RT-PCR, followed by sequence alignment and phylogenetic analysis.

A total of 19 viruses were identified across the seven strains, distributed among 12 families. +ssRNA viruses were identified, belonging to Botourmiaviridae (four viruses), Deltaflexiviridae (one virus), Fusariviridae (two viruses), Narnaviridae (two viruses), Ambiguiviridae (two viruses), and Potyviridae (one virus). −ssRNA viruses were assigned Mymonaviridaeto (two viruses), and Mycophioviridae (one virus). dsRNA viruses were found, including Chrysoviridae (one virus), Partitiviridae (one virus), Totiviridae (one virus), and Polymycoviridae (one virus).

This study uses metatranscriptome technology to expand our understanding of the diversity of mycoviruses in C. cassiicola and provides a rich resource for future studies on mycovirus diversity and taxonomy.