Silene latifolia and Microbotryum violaceum : Molecular, cellular and Morphological studies on plant sexuality and parasitic fungus operating it.

Silene latifolia 和 Microbotryum violaceum ：植物性行为及其寄生真菌的分子、细胞和形态学研究。

基本信息

批准号：
17370022
负责人：
KAWANO Shigeyuki
金额：
$ 9.28万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

The development of male organs is induced in female flowers of the dioecious plant Silene latifolia by infection with the smut 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.Using natural scanning electron microscopy, Nomarski interference microscopy, and fluorescence microscopy, we investigated the morphological modifications of the host plant resulting from this parasitism and the localization of smut hyphae in the flower bud. Flowers of infected plants lasted significantly longer than those of healthy plants, probably because the infection strengthened floral organs, such as the flower base and the anther filaments. Smut hyphae were observed throughout all organs of the young flower buds of infected plants, including sepals, petals, stamens, and pistil primordia. In healthy female … More flowers, anthers initiated sporogenous cell formation, but lacked parietal cell layers. By contrast, the parietal cell layers of infected female flowers differentiated into tapetal tissue, middle cell layers, and endothecial layers, as in the anthers of healthy male flowers. Smut spore formation in the infected anther was initiated in intercellular regions between the sporogenous cells, resulting in degeneration of premature sporogenous cells, tapetal tissue, and middle cell layers. The development of the endothecial layers and epidermis in the infected anther were morphologically normal.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.Silene latifolia is a dioecious plant in which sex is determined by X and Y chromosomes. Expression of the B-function gene SLM2, an ortholog of PISTILLATA (P1) in Arabidopsis, was examined by in situ hybridization. SLM2 was not expressed in suppressed stamens of female flowers, but was expressed in developing stamens of smut-infected female flowers. These results indicate that the control of SLM2 is independent of the presence of the Y chromosome. Smut-infected females provide a useful system for clarifying the relationship between the B-function gene and the sex determination factor. Less

雄性器官的发育是在雌雄同体的植物锡烯拉蒂利亚（Silene latifolia）的雌花中，通过感染smut真菌微生物紫罗兰色的感染。健康的雌花中的雄蕊仅生长到第6阶段，而那些在感染的雌花发育到成熟阶段的雄蕊（第12阶段），在该阶段（第12阶段）中，雄蕊充满了真菌端孢子而不是花粉粒。使用自然扫描电子显微镜，nomarski nomarski干涉显微镜和浮动式的工厂，我们调查了众多的群体修饰，我们研究了众所周知的工厂修改。花蕾中的菌丝。感染植物的花朵的持续时间明显比健康植物的花更长，这可能是因为感染增强了花卉器官，例如花碱和其他细丝。在感染植物的年轻花蕾的所有器官中都观察到了斑点菌丝，包括萼片，花瓣，雄蕊和雌蕊原始。在健康的雌性……更多的花朵中，花药引发了孢子源性细胞的形成，但缺乏私下细胞层。相比之下，如健康的雄花的其他形象一样，被感染的雌花的巴拉蒂尔细胞层分化为tap虫组织，中间细胞层和内皮层。在受感染的另一个感染中形成臭味酱是在孢子源细胞之间的细胞间区域中启动的，导致过早的孢子细胞，tap虫组织和中部细胞层变性。感染中内胸层和表皮的发展在形态上是正常的。为了研究这些宿主 - 寄生虫相互作用，通过高压冻结方法固定后，通过电子显微镜检查了通过电子显微镜检查的幼芽和真菌引起的感染雌花的花药。使用这种方法，我们发现这种真菌的寄生菌丝包含几种细胞外蔬菜，并且直至第8阶段都具有一致的外观。在那个阶段，观察到寄生虫在感染雌性花药中与垂死的孢子虫细胞相邻。在第9阶段，观察到死亡和垂死的孢子源细胞数量增加，其中真菌发育的孢子菌菌丝并形成初始端孢子。在此阶段，几种类型的电子致密材料与某些真菌相近。最初的端孢子含有两种类型的吸尘器，真菌细胞壁含有丰富的碳氢化物，如银蛋白染色所示。孢子源细胞可能对真菌感染敏感，从而导致破坏。此外，真菌在另一种中加速细胞死亡，并利用死去的宿主细胞形成成熟的端孢子。Silenelatifolia是一种富裕的植物，其中X和Y染色体确定性别。通过原位杂交检查了B功能基因SLM2（拟南芥中的雌性植物（P1））的表达。 SLM2在抑制的雌花雄蕊中没有表达，而是在发育中感染的雌花的雄蕊中表达。这些结果表明，SLM2的控制与Y染色体的存在无关。被SMUT感染的女性提供了一个有用的系统，用于阐明B功能基因与性别确定因子之间的关系。较少的