TY - JOUR AU - BRUNO, Giovanni Luigi AU - IPPOLITO, Maria Paola AU - MANNERUCCI, Francesco AU - BRAGAZZI, Luca AU - TOMMASI, Franca PY - 2021/09/13 Y2 - 2024/03/29 TI - Physiological responses of ‘Italia’ grapevines infected with Esca pathogens JF - Phytopathologia Mediterranea JA - Phytopathol. Mediterr. VL - 60 IS - 2 SE - Articles DO - 10.36253/phyto-12171 UR - https://oajournals.fupress.net/index.php/pm/article/view/12171 SP - 321-336 AB - <p>Physiological features were examined of a 20-year-old <em>Vitis vinifera</em> ‘Italia’ table grape vineyard cropped in Apulia, Italy. Healthy vines with no foliar symptoms and any indications of wood or berry alterations, vines with natural wood infections by <em>Phaeoacremonium minimum </em>(syn. <em>P</em>. <em>aleophilum</em>) and <em>Phaeomoniella</em> <em>chlamydospora</em> showing brown wood streaking symptoms, and vines naturally infected with <em>P. minimum</em>, <em>P. chlamydospora</em> and <em>Fomitiporia mediterranea</em> with brown wood streaking and white rot symptoms, were surveyed. Bleeding xylem sap, collected at bud-break from healthy vines showed the greatest total ascorbic acid level, while vines with brown wood streaking and white rot had the greatest viscosity coefficient, glutathione concentration, and plant growth regulator activities. Compared to healthy vines, leaves of wood affected vines, sampled during the unfolded leaf, fruit setting, cluster closing and bunch ripening vine growth stages, had reduced fresh and dry weights, total chlorophyll concentrations, and increased leaf surface area. Low ascorbic acid and reduced glutathione concentrations, weak redox state, and moderate levels of dehydroascorbic acid and oxidized glutathione were also detected in these vines. Analyses also detected reduced activities of dehydroascorbate reductase, ascorbate free radical reductase and glutathione reductase in diseased vines. The cell membrane damage, associated with lipid peroxidation, was coupled with high hydrogen peroxide concentrations. These changes could contribute to the cell death of leaves and foliar symptom development. The ascorbate-glutathione cycle supports grapevine susceptibility to Esca complex-associated fungi.</p> ER -