Metagenomic next-generation sequencing of viruses infecting grapevines

Next-generation sequencing (NGS) technologies, for the first time, provide a truly "complete" representation of the viral (and other) pathogens present in a host organism. This is achieved in an unbiased way, and without any prior biological or molecular knowledge of these pathogen(s). During recent years a number of broad approaches, for most of the popular NGS platforms, have been developed. Here we describe such a protocol-one that accurately and reliably analyze viruses (and viroids) infecting grapevine. Our strategy relies on the synthesis of cDNA sequencing libraries from dsRNA, extracted from diseased grapevine tissues; the sequencing of these on an Illumina platform, and a streamlined bioinformatics pipeline to analyze the NGS data, yielding the virus composition (virome) of a specific grapevine tissue type, organ, entire plant, or even a vineyard.