Jürges G, Kassemeyer H-H, Dürrenberger M, Düggelin M, Nick P
Institute of Botany 1, University of Karlsruhe, Germany.
Plant Biol (Stuttg). 2009 Nov;11(6):886-98. doi: 10.1111/j.1438-8677.2008.00182.x.
In order to obtain insight into host responses to grapevine downy mildew (Plasmopara viticola), we compared pathogen development on a panel of Vitis species from North America, Asia and Europe. Leaf discs from different host species were inoculated in parallel, and the colonisation of the mesophyll was visualised by aniline blue staining and quantified with respect to infection incidence and mycelial growth. In parallel, the morphology of guard cells was screened for the presence of an internal cuticular rim after staining with acridine orange and using low-temperature scanning electron microscopy. We observed three response patterns: (i) inhibition of pathogen development early after attachment of zoospores; (ii) successful colonisation of the mesophyll by the pathogen; and (iii) aberrant development, where the pathogen does not attach to guard cells, but produces hyphae on the leaf surface without formation of viable sporangiophores. Inhibition is observed in the North American and Siberian species, successful colonisation prevails in the European hosts, and surface hyphae are found on non-Siberian Asiatic species. We propose that the interaction between host and pathogen is under control of specific signals that have been subject to evolutionary diversification.
为了深入了解宿主对葡萄霜霉病（葡萄生单轴霉）的反应，我们比较了北美、亚洲和欧洲的一组葡萄属物种上病原菌的发育情况。对不同宿主物种的叶片圆片进行平行接种，通过苯胺蓝染色观察叶肉的定殖情况，并就感染发生率和菌丝生长进行量化。同时，在用吖啶橙染色并使用低温扫描电子显微镜观察后，筛选保卫细胞的形态，以确定是否存在内部角质层边缘。我们观察到三种反应模式：（i）游动孢子附着后早期病原菌发育受到抑制；（ii）病原菌成功定殖叶肉；（iii）异常发育，即病原菌不附着于保卫细胞，而是在叶表面产生菌丝，不形成有活力的孢子囊梗。在北美和西伯利亚物种中观察到抑制现象，在欧洲宿主中成功定殖占主导，在非西伯利亚亚洲物种上发现表面菌丝。我们认为宿主与病原菌之间的相互作用受特定信号控制，这些信号经历了进化多样化。
