Magnin-Robert Maryline, Letousey Patricia, Spagnolo Alessandro, Rabenoelina Fanja, Jacquens Lucile, Mercier Laurence, Cl Ment Christophe, Fontaine Florence
Université de Reims Champagne-Ardenne, URVVC-SE EA 2069, Laboratoire de Stress, Défenses et Reproduction des Plantes, UFR Sciences Exactes et Naturelles, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France.
Moët and Chandon, 20 Avenue de Champagne, 51200 Epernay, France.
Funct Plant Biol. 2011 Nov;38(11):856-866. doi: 10.1071/FP11083.
Esca is a destructive disease in grapevines (Vitis vinifera L.) caused by at least three fungi and characterised by two different external symptoms, the apoplectic and leaf stripe form. This latter form can be discerned as soon as symptoms become visible, but the preceding discrete signs during incubation are poorly or not understood. To further understand the development of the leaf stripe form, the period preceding and following the appearance of symptoms was investigated by studying physiological and molecular markers associated with photosynthetic mechanisms and stress response. No perturbation of any targeted metabolism was observed in asymptomatic leaves of asymptomatic canes from vines showing the leaf stripe form of esca. Conversely, drastic alterations of photosynthesis functions were registered in presymptomatic leaves, as revealed by the decrease of gas exchange and chlorophyll fluorescence, and the repression of photosynthesis-related genes. These alterations were amplified during symptom development. Expression of defence-related genes was affected and detected early in presymptomatic leaves and amplified during symptom expression. Our results suggest that grapevines may react precociously by reducing photosynthesis and triggering defence mechanisms in response to the leaf stripe form of esca.
葡萄枝干病害（Esca）是一种由至少三种真菌引起的葡萄（欧亚种葡萄）毁灭性病害，具有两种不同的外部症状，即中风型和叶纹型。叶纹型症状一旦显现就能被识别出来，但在潜伏期间先前的离散迹象却鲜为人知或未被充分了解。为了进一步了解叶纹型病害的发展过程，通过研究与光合机制和应激反应相关的生理和分子标记，对症状出现前后的时期进行了调查。在表现出叶纹型葡萄枝干病害的葡萄藤无症状茎的无症状叶片中，未观察到任何目标代谢的扰动。相反，如气体交换和叶绿素荧光的降低以及光合作用相关基因的抑制所显示的，在症状出现前的叶片中记录到光合作用功能的剧烈变化。这些变化在症状发展过程中被放大。防御相关基因的表达受到影响，并在症状出现前的叶片中早期检测到，在症状表达期间被放大。我们的结果表明，葡萄藤可能会通过降低光合作用和触发防御机制对叶纹型葡萄枝干病害做出早熟反应。
