Isolation, molecular characterization and virome analysis of culturable wood fungal endophytes in esca symptomatic and asymptomatic grapevine plants

Europe is the world largest grape producer, but in recent years, the report of diseases due to infection by grapevine trunk pathogens (GTPs) is becoming one of the main constraints for viticulture. Among grapevine trunk diseases (GTDs), esca syndrome is one of the most complex, characterized by simultaneous infection of several fungi, which lead to important reduction in yield and quality. Previous characterization of fungal isolates associated to esca syndrome lead to the recognition of at least three important players: Phaeocremonium minimum, Phaemoniella chlamydospora and Fomitiporia mediterranea. Here we isolated and characterised molecularly fungal endophytes directly from field wood tissues of plants showing or not esca symptoms. In addition, to better characterize such collection, a deep RNA sequencing (100M reads in paired-end) to screen for mycovirus presence was performed. Thirty-nine viral genomes were detected, 38 of which were new viral species; some of these viruses infected GTPs, including P. minimum and F. mediterranea. In this work, we reported for the first time a curated collection of grapevine fungal endophytes identifying the associated mycoviruses some of which could be employed in future biotechnological exploitation as biological control agents in sustainable plant protection. This article is protected by copyright. All rights reserved.