Reis Pedro, Magnin-Robert Maryline, Nascimento Teresa, Spagnolo Alessandro, Abou-Mansour Eliane, Fioretti Cristina, Clément Christophe, Rego Cecilia, Fontaine Florence
Centro de Investigação em Agronomia, Alimentos, Ambiente e Paisagem (LEAF), Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisbon, Portugal.
SFR Condorcet, Université de Reims Champagne-Ardenne, URVVC EA 4707, Laboratoire Stress Défenses et Reproduction des Plantes, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2, France.
Plant Dis. 2016 Jun;100(6):1071-1079. doi: 10.1094/PDIS-10-15-1194-RE. Epub 2016 Mar 24.
Botryosphaeria dieback is a grapevine trunk disease with a worldwide distribution associated with Diplodia seriata and Neofusicoccum parvum, among several other Botryosphaeriaceae species. The aforementioned xylem-inhabiting fungi cause wood lesions and leaf and berry symptoms, and eventually lead to the death of the plant. The aim of this work was to develop a simple model system to reproduce the foliar symptoms caused by D. seriata and N. parvum to better characterize fungal pathogenicity and determine the mechanisms involved in symptom development. Green stems of grafted 'Aragonez' grapevine cuttings were inoculated with three isolates of N. parvum and two isolates of D. seriata with different degrees of virulence and the experiment was repeated four times from 2011 to 2014. Three months after inoculation, the lesions associated with N. parvum were larger than those associated with D. seriata. Similarly, 8 months after inoculation, the percentage of plants showing foliar symptoms was greater in the N. parvum treatments than in the D. seriata treatments. During the emergence of foliar symptoms, plant stress-related responses were modulated in green stems and leaves, especially a downregulation of superoxide dismutase (SOD) and fasciclin-like arabinogalactan protein (fascAGP) and an upregulation of stilbene synthase (STS) genes with an accumulation of phenolics. In conclusion, the simple model system developed allowed a good characterization of isolate pathogenicity and correlation with foliar symptoms of Botryosphaeria dieback, namely spots on leaf margin and blade.
葡萄座腔菌属溃疡病是一种在全球范围内分布的葡萄树干病害，与葡萄座腔菌和微小新壳梭孢等多种葡萄座腔菌科物种有关。上述木质部内生真菌会导致木质部损伤以及叶片和果实症状，最终导致植株死亡。这项工作的目的是建立一个简单的模型系统，以重现由葡萄座腔菌和微小新壳梭孢引起的叶片症状，从而更好地表征真菌致病性，并确定症状发展所涉及的机制。用三株不同毒力的微小新壳梭孢分离株和两株葡萄座腔菌分离株接种嫁接的‘阿拉哥内斯’葡萄插条的绿色茎段，该实验在2011年至2014年重复进行了四次。接种三个月后，与微小新壳梭孢相关的病斑比与葡萄座腔菌相关的病斑更大。同样，接种八个月后，微小新壳梭孢处理组中出现叶片症状的植株百分比高于葡萄座腔菌处理组。在叶片症状出现期间，绿色茎段和叶片中的植物应激相关反应受到调节，特别是超氧化物歧化酶（SOD）和类成束蛋白阿拉伯半乳聚糖蛋白（fascAGP）的下调以及芪合酶（STS）基因的上调和酚类物质的积累。总之，所建立的简单模型系统能够很好地表征分离株的致病性，并与葡萄座腔菌属溃疡病的叶片症状（即叶缘和叶片上的斑点）相关联。
