Ultrastructural analysis of the behavior of the dimorphic fungus Microbotryum violaceum in fungus-induced anthers of female Silene latifolia flowers
Ultrastructural analysis of the behavior of the dimorphic fungus Microbotryum violaceum in fungus-induced anthers of female Silene latifolia flowers
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DOI：
10.1007/s00709-005-0113-7
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发表时间：
2005-12-01
期刊：
影响因子：
2.9
通讯作者：
Kawano, S
中科院分区：
文献类型：
--
作者：
Uchida, W;Matsunaga, S;Kawano, S
通过感染微葡萄孢菌（Microbotryum violaceum）诱导雌雄异株植物宽叶蝇子草（Silene latifolia）的雌花发育雄性器官。健康雌花中的雄蕊仅生长到第6阶段，而感染雌花中的雄蕊发育到成熟阶段（第12阶段），在该阶段雄蕊充满真菌冬孢子而不是花粉粒。为了研究这些主机-寄生虫的相互作用，年轻的花蕾和真菌诱导的花药感染的雌花进行了检查，通过电子显微镜下固定的高压冷冻方法。使用这种方法，我们发现这种真菌的寄生菌丝含有几个细胞外囊泡，并具有一致的外观，直到第8阶段。在此阶段，在受感染的雌性花药中，在垂死的造孢细胞附近观察到寄生菌丝。在第9阶段，观察到死亡和垂死的造孢细胞的数量增加，其中真菌的造孢菌丝发育并形成初始冬孢子。在这个阶段，一些真菌附近存在几种类型的电子致密物质。银蛋白染色显示，初始冬孢子含有两种类型的液泡，真菌细胞壁含有丰富的碳水化合物。造孢细胞可能对真菌的感染很敏感，导致破裂。此外，真菌加速花药中的细胞死亡，并利用死亡的宿主细胞的成分形成成熟的冬孢子。
The development of male organs is induced in female flowers of the dioecious plant Silene latifolia by infection with the fungus Microbotryum violaceum. Stamens in a healthy female flower grow only to stage 6, whereas those in an infected female flower develop to the mature stage (stage 12), at which the stamens are filled with fungal teliospores instead of pollen grains. To investigate these host-parasite interactions, young floral buds and fungus-induced anthers of infected female flowers were examined by electron microscopy following fixation by a high-pressure freezing method. Using this approach, we found that parasitic hyphae of this fungus contain several extracellular vesicles and have a consistent appearance up to stage 8. At that stage, parasitic hyphae are observed adjacent to dying sporogenous cells in the infected female anther. At stage 9, an increased number of dead and dying sporogenous cells is observed, among which the sporogenous hyphae of the fungus develop and form initial teliospores. Several types of electron-dense material are present in proximity to some fungi at this stage. The initial teliospores contain two types of vacuoles, and the fungus cell wall contains abundant carbohydrate, as revealed by silver protein staining. The sporogenous cell is probably sensitive to infection by the fungus, resulting in disruption. In addition, the fungus accelerates cell death in the anther and utilizes constituents of the dead host cell to form the mature teliospore.