Rearrangement of the actin filament and microtubule cytoskeleton during induction of microspore embryogenesis in Brassica napus L. cv. Topas
Rearrangement of the actin filament and microtubule cytoskeleton during induction of microspore embryogenesis in Brassica napus L. cv. Topas
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DOI：
10.1007/bf01282157
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发表时间：
2000-01-01
期刊：
影响因子：
2.9
通讯作者：
Simmonds, DH
中科院分区：
文献类型：
--
作者：
Gervais, C;Newcomb, W;Simmonds, DH
在热和细胞松弛素 D 诱导的甘蓝型油菜小孢子胚胎发生过程中，检查了肌动蛋白丝和微管细胞骨架的变化。 Topas 分别采用罗丹明鬼笔环肽和免疫荧光标记。细胞核从其外围移位到细胞中更中心的位置，核周肌动蛋白微丝和微管延伸到细胞质上。热处理诱导小孢子中前期微管带的形成；前期带与第一次花粉有丝分裂无关。未观察到肌动蛋白丝与前期带的关联。有丝分裂纺锤体的方向和位置发生了改变，并且它被随机定向的微丝包围。成膜体含有微丝和微管，与花粉有丝分裂 I 一样，但它占据了更中心的位置。在没有热处理的情况下，经过短暂的细胞松弛素 D 处理的小孢子中也发生了细胞骨架重组。小孢子的细胞松弛素 D 处理导致有丝分裂纺锤体错位、成膜体破坏和对称分裂，并导致胚胎发生，证实正常的肌动蛋白细胞骨架具有阻止诱导胚胎发生的作用。
Changes in the actin filament and microtubule cytoskeleton were examined during heat- and cytochalasin D-induced embryogenesis in microspores of Brassica napus cv. Topas by rhodamine phalloidin and immunofluorescence labelling respectively. The nucleus was displaced from its peripheral to a more central position in the cell, and perinuclear actin microfilaments and microtubules extended onto the cytoplasm. Heat treatment induced the formation of a preprophase band of microtubules in microspores; preprophase bands are not associated with the first pollen mitosis. Actin filament association with the preprophase band was not observed. The orientation and position of the mitotic spindle were altered, and it was surrounded with randomly oriented microfilaments. The phragmoplast contained microfilaments and microtubules, as in pollen mitosis I, but it assumed a more central position. Cytoskeletal reorganisation also occurred in microspores subjected to a short cytochalasin D treatment, in the absence of a heat treatment. Cytochalasin D treatment of microspores resulted in dislocated mitotic spindles, disrupted phragmoplasts, and symmetric divisions and led to embryogenesis, confirming that a normal actin cytoskeleton has a role in preventing the induction of embryogenesis.