Approaches of next generation sequencing to investigate grapevine diseases of unknown aetiology

Analysis of small RNAs (sRNAs) and /or double-stranded RNAs (dsRNA) libraries by next generation sequencing (NGS) is a novel technology that is proving increasingly useful for the discovery of previously unknown viruses associated with diseases of undetermined aetiology (e.g. Loconsole et al., 2012). Among virus-like diseases of the grapevine, enations, an erratic disorder whose appearance may depend on seasonal conditions (Martelli and Boudon Padieu, 2006), is characterized by morphological modifications of the leaves that recall the consequences of hormonal unbalance. Even though graft transmissibility of enation disease supports its viral etiology, the putative agent has not yet been identified. NGS technology was used to investigate the “virome” of enation-infected grapevines and of an accession of cv. Moscato giallo showing an unusual interveinal spring chlorosis, that tends to turn whitish-yellow as the season advances