Fungal pathogen uses sex pheromone receptor for chemotropic sensing of host plant signals
Fungal pathogen uses sex pheromone receptor for chemotropic sensing of host plant signals
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DOI：
10.1038/nature15516
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发表时间：
2015-11-26
期刊：
影响因子：
64.8
通讯作者：
Di Pietro, Antonio
中科院分区：
文献类型：
--
作者：
Turra, David;El Ghalid, Mennat;Di Pietro, Antonio
一个多世纪以来，人们已知真菌病原体和共生体会根据宿主植物的化学刺激来调整菌丝生长(1,2)。然而，植物信号的性质以及趋化反应的机制仍然难以捉摸(3)。在这里，我们发现，土壤中的植物病原体尖孢镰刀菌向宿主番茄（番茄）的根部定向生长是由分泌的 III 类过氧化物酶（所有陆地植物中存在的一类含血红素酶）的催化活性触发的 (4)。趋化反应需要真菌细胞完整性丝裂原激活蛋白激酶 (MAPK) 级联 (5) 和七次跨膜蛋白 Ste2（酿酒酵母性信息素 a 受体的功能同源物）的保守元件 (6)。我们进一步表明，尖镰孢菌丝向糖和氨基酸等营养源定向生长是由功能独特的 MAPK 级联控制的。这些结果揭示了根部定殖真菌中潜在保守的趋化机制，并提出了真菌信息素传感机制在土壤等复杂环境中定位植物宿主的新功能。
For more than a century, fungal pathogens and symbionts have been known to orient hyphal growth towards chemical stimuli from the host plant(1,2). However, the nature of the plant signals as well as the mechanisms underlying the chemotropic response have remained elusive(3). Here we show that directed growth of the soil-inhabiting plant pathogen Fusarium oxysporum towards the roots of the host tomato (Solanum lycopersicum) is triggered by the catalytic activity of secreted class III peroxidases, a family of haem-containing enzymes present in all land plants(4). The chemotropic response requires conserved elements of the fungal cell integrity mitogen-activated protein kinase (MAPK) cascade(5) and the seven-pass transmembrane protein Ste2, a functional homologue of the Saccharomyces cerevisiae sex pheromone a receptor(6). We further show that directed hyphal growth of F. oxysporum towards nutrient sources such as sugars and amino acids is governed by a functionally distinct MAPK cascade. These results reveal a potentially conserved chemotropic mechanism in root-colonizing fungi, and suggest a new function for the fungal pheromone-sensing machinery in locating plant hosts in a complex environment such as the soil.