The signalling mucin Msb2 regulates surface sensing and host penetration via BMP1 MAP kinase signalling in Botrytis cinerea
The signalling mucin Msb2 regulates surface sensing and host penetration via BMP1 MAP kinase signalling in Botrytis cinerea
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DOI：
10.1111/mpp.12234
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发表时间：
2015-10-01
影响因子：
4.9
通讯作者：
Hahn, Matthias
中科院分区：
文献类型：
--
作者：
Leroch, Michaela;Mueller, Nathalie;Hahn, Matthias
灰霉病是一种坏死性真菌，广泛感染水果、蔬菜和花卉作物。寄主角质层的渗透是通过响应适当的植物表面信号而形成的感染结构发生的。这些结构的分化需要高度保守的丝裂原活化蛋白（MAP）激酶级联，包括MAP激酶BMP1。在酵母和几种植物病原真菌中，信号粘蛋白Msb2已被证明参与表面识别和MAP激酶激活。在这项研究中，产生了一个葡萄球菌msb2突变体并对其进行了鉴定。突变体生长、产孢、菌核形成和抗逆性正常。在缺乏营养的情况下，可以观察到多芽管发芽的异常现象。在有糖存在的情况下，萌发正常，但msb2的萌发几乎不能在坚硬的表面形成附着胞或感染垫。然而，msb2突变体在不同寄主植物上的病变形成仅表现出中度延迟，并且形成与野生型相似的扩展病变。尽管野生型在坚硬表面萌发的最初几个小时内BMP1磷酸化水平升高，但msb2突变体的磷酸化水平却大幅降低。一些编码分泌蛋白的基因在萌发过程中被BMP1和Msb2共同调控。综上所述，B.cinerea Msb2可能代表了一种胚和菌丝的硬表面传感器，通过激活BMP1 MAP激酶途径触发感染结构的形成。
Botrytis cinerea is a necrotrophic fungus that infects a wide range of fruit, vegetable and flower crops. Penetration of the host cuticle occurs via infection structures that are formed in response to appropriate plant surface signals. The differentiation of these structures requires a highly conserved mitogen-activated protein (MAP) kinase cascade including the MAP kinase BMP1. In yeast and several plant-pathogenic fungi, the signalling mucin Msb2 has been shown to be involved in surface recognition and MAP kinase activation. In this study, a B.cinerea msb2 mutant was generated and characterized. The mutant showed normal growth, sporulation, sclerotia formation and stress resistance. In the absence of nutrients, abnormal germination with multiple germ tubes was observed. In the presence of sugars, normal germination occurred, but msb2 germlings were almost unable to form appressoria or infection cushions on hard surfaces. Nevertheless, the msb2 mutant showed only a moderate delay in lesion formation on different host plants, and formed expanding lesions similar to the wild-type. Although the wild-type showed increasing BMP1 phosphorylation during the first hours of germination on hard surfaces, the phosphorylation levels in the msb2 mutant were strongly reduced. Several genes encoding secreted proteins were found to be co-regulated by BMP1 and Msb2 during germination. Taken together, B.cinerea Msb2 is likely to represent a hard surface sensor of germlings and hyphae that triggers infection structure formation via the activation of the BMP1 MAP kinase pathway.