Sinclair Gabriela C, Travadon Renaud, Eschen Paula J, Wallis Christopher, Baumgartner Kendra, Delmas Chloé E L, Hnizdor Joshua F, Bartlett Megan K
Department of Viticulture & Enology, University of California, One Shields Avenue, Davis, CA 95616, USA.
E2S UPPA, CNRS, IPREM, Université de Pau et des Pays de l'Adour, 64000 Pau, France.
J Exp Bot. 2025 Aug 5;76(11):3172-3185. doi: 10.1093/jxb/eraf103.
Eutypa lata is a fungal pathogen of grapevine that causes widespread economic damage and threatens vineyard longevity worldwide. This study was initiated to further understanding of how grapevines resist E. lata infections, using an integrated approach combining inoculation assays in the greenhouse with physiological and biochemical measurements. Resistant 'Zinfandel' and susceptible 'Syrah' grapevines were subjected to control and inoculation treatments, and assessed for gas exchange, water status, photosynthetic biochemistry, hydraulic conductivity, wood chemistry, and fungal spread (lesion length). Infection reduced leaf photochemical function and gas exchange in Zinfandel and increased these variables in Syrah (P<0.05). Infection produced shorter lesions in Zinfandel (P<0.05), suggesting that down-regulating gas exchange limited pathogen spread by reducing the carbon supply to the pathogen or fungal movement in the transpiration stream. Neither cultivar up-regulated wood defense compounds in response to infection, but proanthocyanidin and catechin levels were constitutively higher in Zinfandel, and stilbenoid and flavonoid contents were constitutively higher in Syrah (P<0.05). Altogether, this study is the first to show that, counterintuitively, down-regulating physiological function in response to infection improves long-term resistance to E. lata. Screening responses in photochemical function or gas exchange could provide a high-throughput alternative to measuring lesion lengths in assessing resistance.
葡萄座腔菌是葡萄的一种真菌病原体，会造成广泛的经济损失，并威胁到全球葡萄园的寿命。本研究旨在通过将温室接种试验与生理生化测量相结合的综合方法，进一步了解葡萄如何抵抗葡萄座腔菌的感染。对抗病的“仙粉黛”葡萄和感病的“西拉”葡萄进行对照和接种处理，并评估气体交换、水分状况、光合生物化学、导水率、木材化学和真菌传播（病斑长度）。感染降低了仙粉黛葡萄的叶片光化学功能和气体交换，而增加了西拉葡萄的这些变量（P<0.05）。感染在仙粉黛葡萄上产生的病斑较短（P<0.05），这表明下调气体交换通过减少病原体的碳供应或蒸腾流中真菌的移动来限制病原体的传播。两种品种在感染后均未上调木材防御化合物，但原花青素和儿茶素水平在仙粉黛葡萄中本底较高，而芪类和黄酮类含量在西拉葡萄中本底较高（P<0.05）。总之，本研究首次表明，与直觉相反，感染后下调生理功能可提高对葡萄座腔菌的长期抗性。筛选光化学功能或气体交换反应可为评估抗性时测量病斑长度提供一种高通量替代方法。
