Identification of Mycoviral Infections

High-throughput sequencing of total RNA has permitted the detection of novel mycoviruses in fungi with different types of genomes, including mycoviruses with double-stranded RNA, single-stranded positive- or negative-stranded RNA, or single-stranded DNA genomes. However, in silico detection of mycoviruses is not always sufficient to guarantee their presence in sequenced samples, especially in the case of the discovery of unique mycoviruses, and additional analyses are required to validate in vivo the data obtained by bioinformatics analysis. This chapter provides comprehensive protocols for the extraction of total RNA from the plant pathogenic fungus Botrytis cinerea for next-generation sequencing (NGS), outlines the bioinformatics pipeline designed and followed to detect mycoviruses in the sequenced samples, and details the detection in vivo and the complete molecular characterization of the mycoviruses identified in silico.