Microscopic studies on attachment and differentiation of zoospores of the phytopathogenic fungus Aphanomyces cochlioides
Microscopic studies on attachment and differentiation of zoospores of the phytopathogenic fungus Aphanomyces cochlioides
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DOI：
10.1007/pl00013063
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发表时间：
2002-05-01
影响因子：
1.2
通讯作者：
Tahara, Satoshi
中科院分区：
文献类型：
--
作者：
Islam, Md. Tofazzal;Ito, Toshiaki;Tahara, Satoshi
用光学显微镜和扫描电子显微镜研究了植物病原真菌CochlioidS游动孢子与寄主专一性引诱剂和G蛋白激活剂Mastoparan相互作用时游动孢子的聚集、附着和分化方式。当游动孢子靠近寄主根时，它似乎停了下来，然后将前鞭毛盘绕在身体上。停止的游动孢子似乎与寄主表面接触，其后鞭毛逐渐将包囊的游动孢子吸引到根表面。然后，在后鞭毛的帮助下，孢子精确地停靠在其腹面的根表面上，并通过释放一些粘性物质来锚定自己。贴壁的孢子脱落鞭毛后呈球形，并迅速形成膨大的囊壁，形成光滑的囊壳，最后变成表面起皱的较小的囊孢子。相反，人工膜上的游动孢子在人工膜上被激活后，游动孢子会在包囊前利用后鞭毛聚集。这些不同的现象表明，Cochlioid游动孢子可能利用其后鞭毛成功停靠在寄主表面或在没有寄主的情况下聚集包囊孢子。
The mode of aggregation, attachment and differentiation of zoospores of the phytopathogenic fungus Aphanomyces cochlioides when interacting with the host and a host-specific attractant and a G-protein activator, mastoparan, was studied by light and scanning electron microscopy. When a zoospore approached very close to the host root, it seemed to halt, then coiled its anterior flagellum on its body. The halted zoospore appeared to contact the host surface with its posterior flagellum, which gradually drew the encysting zoospore onto the root surface. The spore then docked precisely on the root surface at its ventral face with the help of the posterior flagellum and anchored itself by releasing some adhesive materials. The adherent spore became a spherical after shedding its flagella and rapidly turned into an expanded cyst forming a smooth cyst coat around it, and finally changed into a smaller cystospore covered with a wrinkled surface. In contrast, the mastoparan- or cochliophilin A-stimulated zoospores on artificial membranes aggregated by using their posterior flagella before encystment. These contrasting phenomena suggest that A. cochlioides zoospores may use their posterior flagella for successful docking on the host surface or for aggregation of encysting spores in the absence of the host.