(1) Background. An extensive survey of grapevine-sown cover crops and spontaneous weed flora was conducted from 2019 to 2020 in organic vineyards in six European countries (France, Italy, Romania, Slovenia, Spain, Switzerland). Our main objective was to detect and identify the presence of Cylindrocarpon-like asexual morphs species associated with black-foot disease on their roots. (2) Methods. Fungal isolations from root fragments were performed on culture media. Cylindrocarpon-like asexual morph species were identified by analyzing the DNA sequence data of the histone H3 (his3) gene region. In all, 685 plants belonging to different botanical families and genera were analyzed. Cylindrocarpon-like asexual morphs were recovered from 68 plants (9.9% of the total) and approximately 0.97% of the plated root fragments. (3) Results. Three fungal species (Dactylonectria alcacerensis, Dactylonectria torresensis, Ilyonectria robusta) were identified. Dactylonectria torresensis was the most frequent, and was isolated from many cover crop species in all six countries. A principal component analysis with the vineyard variables showed that seasonal temperatures and organic matter soil content correlated positively with Cylindrocarpon-like asexual morphs incidence. (4) Conclusions. The presence of Cylindrocarpon-like asexual morphs on roots of cover crops suggests that they can potentially act as alternative hosts for long-term survival or to increase inoculum levels in vineyard soils.

Sugar transporters play a crucial role in plant responses to environmental factors. During plant–pathogen interactions, it is well established that sugar transporters and cell wall invertases are essential for regulating sugar availability at the plant–pathogen interface, impacting both plant resistance and pathogen proliferation. Despite these insights, their role in grapevine defence against pathogens remains underexplored. We examined the expression of sugar transporter and invertase genes in grape leaves infected with the necrotrophic fungus Botrytis cinerea . Our results highlighted significant coordinated upregulation of VvHT5 , VvcwINV and defence genes, suggesting a role in enhancing sink strength in infected leaves and implementing host defences. Heterologous expression of GFP‐fused proteins confirmed VvHT5 as a plasma membrane‐localized hexose symporter and phylogenetic analysis indicated its close relation with STP13‐like proteins, which are known to be implicated in host resistance across several plant–pathogen interactions. VvHT5 was heterologously expressed in Arabidopsis thaliana , resulting in high constitutive expression of the VvHT5 protein and increased glucose uptake activity. Phenotypic analysis revealed that VvHT5 enhanced basal resistance to B . cinerea and rescued the wild‐type phenotype in STP13‐deficient plants, indicating that VvHT5 is the grapevine orthologue of AtSTP13. Our findings suggest that VvHT5 may facilitate the reabsorption of extracellular monosaccharides, released from VvcwINV activity or damaged tissues during infection. This activity allows host cells to compete with necrotrophic pathogens for extracellular hexoses, thereby restricting sugar availability to the fungus. It would also support host metabolic demands for defence or serve as a signalling mechanism to orchestrate intracellular processes.