Bénard-Gellon M, Farine S, Goddard M L, Schmitt M, Stempien E, Pensec F, Laloue H, Mazet-Kieffer F, Fontaine F, Larignon P, Chong J, Tarnus C, Bertsch C
Laboratoire Vigne Biotechnologie et Environnement EA 3991, Université de Haute-Alsace, 33, rue de Herrlisheim, BP 68008, Colmar Cedex, France,
Protoplasma. 2015 Mar;252(2):679-87. doi: 10.1007/s00709-014-0716-y. Epub 2014 Oct 17.
Botryosphaeria dieback, esca and Eutypa dieback are three economic major grapevine trunk diseases that cause severe yield reduction in vineyards worldwide. The frequency of disease symptoms has increased considerably over the past decade, and no efficient treatment is currently available to control these diseases. The different fungi associated with grapevine trunk diseases mainly induce necrotic wood and characteristic foliar symptoms. In this context, fungi virulence factors and host invasion are not well understood. We hypothesise that extracellular proteins produced by Diplodia seriata and Neofusicoccum parvum, two causal agents associated with Botryosphaeria dieback, are virulence factors responsible for the pathogenicity. In our previous work, we demonstrated that the total extracellular compounds produced by N. parvum induced more necrosis on Chardonnay calli and triggered a different defence gene expression pattern than those produced by D. seriata. Furthermore, this aggressiveness was not clearly correlated with the production of mellein, a characteristic phytotoxin of Botryosphaeriaceae, in our in vitro calli model. To characterise other potential virulence factors and to understand the mechanisms of host invasion by the fungus, we evaluated the profile, quantity and the impact of extracellular proteins produced by these fungi on Vitis vinifera calli necrosis and defence gene expression. Our results reveal that, under the same conditions, N. parvum produces more extracellular proteins and in higher concentrations than D. seriata. With Vitis vinifera cv. Chardonnay cells, we showed that equivalent concentrations of proteins secreted by N. parvum were more aggressive than those of D. seriata in producing necrosis and that they clearly induced more grapevine defence genes.
葡萄座腔菌属溃疡病、葡萄枝干病害和顶枯病是三种主要的经济葡萄树干病害，在全球葡萄园造成严重减产。在过去十年中，病害症状的发生频率显著增加，目前尚无有效的治疗方法来控制这些病害。与葡萄树干病害相关的不同真菌主要诱发木质部坏死和典型的叶片症状。在这种情况下，真菌的毒力因子和宿主侵染机制尚不清楚。我们假设，与葡萄座腔菌属溃疡病相关的两种病原菌——葡萄座腔菌和微小新壳梭孢产生的细胞外蛋白是致病的毒力因子。在我们之前的研究中，我们证明了微小新壳梭孢产生的总细胞外化合物比葡萄座腔菌产生的化合物在霞多丽愈伤组织上诱导了更多的坏死，并引发了不同的防御基因表达模式。此外，在我们的体外愈伤组织模型中，这种侵袭性与葡萄座腔菌科特有的植物毒素——蜜色菌素的产生没有明显关联。为了鉴定其他潜在的毒力因子，并了解真菌侵染宿主的机制，我们评估了这些真菌产生的细胞外蛋白的谱、数量及其对葡萄愈伤组织坏死和防御基因表达的影响。我们的结果表明，在相同条件下，微小新壳梭孢比葡萄座腔菌产生更多且浓度更高的细胞外蛋白。对于葡萄品种霞多丽细胞，我们发现相同浓度的微小新壳梭孢分泌的蛋白在产生坏死方面比葡萄座腔菌分泌的蛋白更具侵袭性，并且它们明显诱导了更多的葡萄防御基因。
