Grapevine and trunk pathogen transcriptomic changes induced by the root biocontrol agent Pythium oligandrum

Trabajo presentado en el 10th International Workshop on Grapevine Trunk Diseases, celebrado en Reims (Francia), del 4 al 7 de julio de 2017Peer reviewe

Control of a fungus involved in grapevine trunk disease (Esca) by using the oomycete, Pythium oligandrum : analysis of the induced resistance

International audienc

Characterization of biocontrol strains of Pythium oligandrum and control of an Esca pathogenic fungus attack

article présenté lors du 2011 APS-IPPC Joint Meeting ; Honolulu - Hawaii (Etats-Unis) - (2011-08-06 - 2011-08-10) / RencontresInternational audienc

Study of Lasidiodiplodia pseudotheobromae, Neofusicoccum parvum and Schizophyllum commune, three pathogenic fungi associated with the Grapevine Trunk Diseases in the North of Tunisia

International audienc

Major changes in grapevine wood microbiota are associated with the onset of esca, a devastating trunk disease

Esca, a major grapevine trunk disease in old grapevines, is associated with the colonization of woody tissues by a broad range of plant pathogenic fungi. To identify which fungal and bacterial species are involved in the onset of this disease, we analysed the microbiota from woody tissues of young (10-year-old) grapevines at an early stage of esca. Using meta-barcoding, 515 fungal and 403 bacterial operational taxonomic units (OTUs) were identified in woody tissues.In situhybridization showed that these fungi and bacteria co-inhabited in grapevine woody tissues. In non-necrotic woody tissues, fungal and bacterial microbiota varied according to organs and seasons but not diseased plant status.Phaeomoniella chlamydospora, involved in the Grapevine trunk disease, was the most abundant species in non-necrotic tissues from healthy plants, suggesting a possible non-pathogenic endophytic behaviour. Most diseased plants (70%) displayed cordons, with their central white-rot necrosis colonized essentially by two plant pathogenic fungi (Fomitiporia mediterranea: 60%-90% andP. chlamydospora: 5%-15%) and by a few bacterial taxa (Sphingomonasspp. andMycobacteriumspp.). The occurrence of a specific association of fungal and bacterial species in cordons from young grapevines expressing esca-foliar symptoms strongly suggests that that microbiota is involved in the onset of this complex disease

Differential responses of three grapevine cultivars to Botryosphaeria dieback

Botryosphaeria dieback is a fungal grapevine trunk disease which represents a threat for viticulture worldwide due to the decreased production of affected plants and their premature death. This dieback is characterized by a typical wood discoloration called “brown stripe”. Herein, a proteome comparison of the brown striped wood from Botryosphaeria dieback-affected standing vines cultivar 'Chardonnay', 'Gewurztraminer' and 'Mourvèdre' was performed. The transcript analysis for 15 targeted genes and the quantification of both total phenolics and specific stilbenes were also performed. Several pathogenesis-related proteins and members of the antioxidant system were more abundant in the brown striped wood of the three cultivars, whereas other defense-related proteins were less abundant. Additionally, total phenolics and some specific stilbenes were more accumulated in the brown striped wood. Strongest differences among the cultivars concerned especially proteins of the primary metabolism, which looked to be particularly impaired in the brown striped wood of 'Chardonnay'. Low abundance of some proteins involved in defense response probably contributes to make global response insufficient to avoid the symptom development. The differential susceptibility of the three grapevine cultivars could be linked to the diverse expression of various proteins involved in defense response, stress tolerance and metabolism