ULTRASTRUCTURE OF ZOOSPOROGENESIS IN PHYTOPHTHORA-CINNAMOMI
ULTRASTRUCTURE OF ZOOSPOROGENESIS IN PHYTOPHTHORA-CINNAMOMI
复制标题
DOI：
10.1016/s0953-7562(09)80072-5
复制
发表时间：
1991-05-01
影响因子：
--
通讯作者：
HARDHAM, AR
中科院分区：
文献类型：
--
作者：
HYDE, GJ;GUBLER, F;HARDHAM, AR
用电子显微镜结合免疫金标记技术研究了肉桂疫霉游动孢子的形成。 游动孢子发生包括成熟的多核孢子囊区室化为许多双鞭毛单核游动孢子。 在此过程开始之前，孢子囊的梨形核规则地分布在整个细胞质中。 一些细胞成分，包括基体和网质体，被发现专门或主要在核的窄极附近。 第二个层次的组织涉及孢子囊皮层的核，其狭窄的极点指向壁。 这些模式是至关重要的，在卵裂过程中的变化顺序，并在建立游动孢子的背腹轴。 游动孢子发生由冷休克启动，并且在20分钟内，在每个狭窄的核极附近和细胞质中的其他地方出现大的卵裂小泡簇。 单克隆抗体Cpw-1标记与切割囊泡的膜密切相关的材料，并且还结合到被提议作为囊泡来源的附近的网质体。 在诱导后20-35分钟之间，皮层中靠近核的窄极的大簇分裂囊泡分散以形成平行于壁的囊泡平面。 这些小泡与从基体上散开的微管紧密排列。 在诱导后25-50分钟之间，孢子囊内部的簇分散，并且它们的囊泡在与皮质中的囊泡平面连接的平面中对齐。 囊泡的平面围绕着包含一个核的胞质的多面体区域。 这些小泡的融合导致孢子囊的区室化。 Cpw-1标记的抗原与新形成的游动孢子原始细胞的质膜紧密结合。 这是第一次，单克隆抗体已被用来确定在真菌孢子囊的裂解囊泡的来源和命运，这项研究的结果表明，在其他疫霉属物种的裂解过程的方面可能需要重新评估。
Zoospore formation in Phytophthora cinnamomi has been studied by electron microscopy in conjunction with immunogold labelling of selected cellular elements. Zoosporogenesis involves the compartmentalization of the mature multinucleate sporangium into a number of biflagellate, uninucleate zoospores. Before the process is initiated, the pyriform nuclei of the sporangium are regularly distributed throughout the cytoplasm. Several cellular elements, including basal bodies and dictyosomes, are found exclusively or predominantly near the narrow poles of nuclei. A second order of organization involves the nuclei of the sporangial cortex whose narrow poles point toward the wall. These patterns are critical to the sequence of changes during cleavage and in establishing the dorso-ventral axis of the zoospore. Zoosporogenesis is initiated by a cold shock, and within 20 min large clusters of cleavage vesicles appear near each narrow nuclear pole and elsewhere in the cytoplasm. Monoclonal antibody Cpw-1 labels material closely associated with the membrane of the cleavage vesicles and also binds to nearby dictyosomes which are proposed as the source of the vesicles. Between 20-35 min after induction, the large clusters of cleavage vesicles near the narrow poles of nuclei in the cortex disperse to form a plane of vesicles parallel to the wall. These vesicles are closely aligned with microtubules that fan out from the basal bodies. Between 25-50 min after induction, clusters in the sporangial interior disperse, and their vesicles align in planes that link with the plane of vesicles in the cortex. The planes of vesicles surround polyhedral domains of cytoplasm that contain one nucleus. Fusion of these vesicles brings about compartmentalization of the sporangium. The antigen labelled by Cpw-1 is closely associated with the plasma membrane of the newly formed zoospore initials. This is the first time that monoclonal antibodies have been used to identify the source and fate of cleavage vesicles in a fungal sporangium, and the results of this study suggest that aspects of the cleavage process in other Phytophthora species may need to be reassessed.