Multiple Exocytotic Markers Accumulate at the Sites of Perifungal Membrane Biogenesis in Arbuscular Mycorrhizas
Multiple Exocytotic Markers Accumulate at the Sites of Perifungal Membrane Biogenesis in Arbuscular Mycorrhizas
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DOI：
10.1093/pcp/pcr170
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发表时间：
2012-01-01
影响因子：
4.9
通讯作者：
Bonfante, P.
中科院分区：
文献类型：
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作者：
Genre, A.;Ivanov, S.;Bonfante, P.
丛枝菌根 (AM) 是由属于球囊菌门的土壤真菌在大多数植物根部建立的共生相互作用。真菌在根组织中的广泛适应主要发生在细胞内，在被所谓的真菌周围膜（宿主质膜的延伸）包围的专门界面室内。通过结合绿色荧光蛋白（GFP）标记蛋白的实时共焦成像和透射电子显微镜（TEM），我们研究了导致该膜生物发生的机制。我们的结果表明，预渗透响应和共生界面构建与广泛的膜动力学相关。正如 TEM 和体内 GFP 成像所揭示的那样，它们涉及胞吐机制的主要组成部分，其中高尔基体主要参与。已知的胞吐作用标记物（例如 VAMP72 家族的 v-SNARE 蛋白和胞吐复合物的 EXO84b 亚基）的标记，可以对真菌周围膜构建中涉及的细胞成分进行实时成像，从而阐明这是如何在细胞内菌丝生长之前发生的。最后，我们的新数据用于说明 AM 真菌渗透过程中预渗透装置内的膜动力学模型。
Arbuscular mycorrhizas (AMs) are symbiotic interactions established within the roots of most plants by soil fungi belonging to the Glomeromycota. The extensive accommodation of the fungus in the root tissues largely takes place intracellularly, within a specialized interface compartment surrounded by the so-called perifungal membrane, an extension of the host plasmalemma. By combining live confocal imaging of green fluorescent protein (GFP)-tagged proteins and transmission electron microscopy (TEM), we have investigated the mechanisms leading to the biogenesis of this membrane. Our results show that pre-penetration responses and symbiotic interface construction are associated with extensive membrane dynamics. They involve the main components of the exocytotic machinery, with a major participation of the Golgi apparatus, as revealed by both TEM and in vivo GFP imaging. The labeling of known exocytosis markers, such as v-SNARE proteins of the VAMP72 family and the EXO84b subunit of the exocyst complex, allowed live imaging of the cell components involved in perifungal membrane construction, clarifying how this takes place ahead of the growing intracellular hypha. Lastly, our novel data are used to illustrate a model of membrane dynamics within the pre-penetration apparatus during AM fungal penetration.