Flavescence dorée (FD) is a grapevine disease caused by phytoplasma and it is one of the most destructive pathologies in Europe. Nowadays, the only strategies used to control the epidemics are insecticides against vector, but more sustainable techniques are required. Completely resistant Vitis vinifera varieties have not been uncovered yet, but differences in susceptibility among cultivars and spontaneous recovery from FD symptoms have been observed. The grapevine cultivar ‘Tocai friulano’ shows very low susceptibility to FD but its defence strategy to counteract the phytoplasma spread has not been deciphered yet. In this work, the mechanisms occurring within ‘Tocai friulano’ FD-infected plants were examined in depth to identify the phytoplasma distribution and the defence pathways involved. In ‘Tocai friulano’ symptoms of FD-infection remained confined near the area where they appeared during all the vegetative season. Analyses of secondary phloem showed a total absence of FD phytoplasma (FDp) in the trunk and its disappearance in 2-year-old arms from July to November, which was different from ‘Pinot gris’, a highly susceptible variety. Diverse modulations of defence genes and accumulation of metabolites were revealed in 1-year-old canes of ‘Tocai friulano’ FD-infected plants, depending on the sanitary status. Symptomatic portions showed high activation of both jasmonate- and salicylate-mediated responses, together with a great accumulation of resveratrol. Whereas activation of jasmonate-mediated response and high content of ε-viniferin were identified in asymptomatic 1-year-old cane portions close to the symptomatic ones. Successful defence mechanisms activated near the symptomatic areas allowed the compartmentation of FD symptoms and phytoplasmas within the infected ‘Tocai friulano’ plants. These results could suggest specific agronomical practices to be adopted during FD management of this variety, and drive research of resistance genes against FD.

Beside the well-known fungal pathologies, grapevine virus diseases are of major importance in grapegrowing areas, also due to the limited knowledge by the professionals of the sector. To face this problem, the PAThOGEN training program was developed, with the aims of: (i) building a high-quality Vocational and Education Training program, (ii) improving the skills of the main actors of the wine sector. The pilot courses were developed in two levels (Basic and Advanced) and made available on a dedicated online platform in 4 languages (French, Italian, Spanish and English). Moreover, two field sessions were organized in each of the 3 partner countries in order to complete the theoretical training. A specific feature of this project was the “demand driven approach” used to conceive the courses. Indeed, a panel of experts and 128 “student-testers” were selected in the 3 countries in the different professional categories to test the training program. 98% of the testers evaluated the training course as “interesting” or “very interesting”. The detailed evaluations allowed us to rework the courses both in terms of content and functionality. The elearning training is now available in the four languages, and the field training is annually organized in France, Italy and Spain.

Limited information is available on the distribution of grapevine red blotch virus (GRBV) in grape-growing regions outside North America. In this study, the presence of GRBV was investigated in 596 grapevine samples coming from different sources in Northern Italy, including rootstock and table grape accessions from ampelographic collections, and commercial varieties with red blotch-like symptoms. Only 'Queen' and 'Incrocio Dalmasso VIII-5' accessions, collected from the CREA-Viticulture and Enology repository of table grape varieties, tested positive for GRBV. Sequencing of fragments from replication and coat protein genes revealed that the two accessions were infected with GRBV isolates belonging to two distinct lineages. While the American origin of 'Queen' could explain the GRBV presence in this accession, the viral infection of the Italian 'Incrocio Dalmasso VIII-5' remains an unsolved mystery.