Elicitor-induced cytoskeletal rearrangement relates to vacuolar dynamics and execution of cell death: In vivo imaging of hypersensitive cell death in tobacco BY-2 cells
Elicitor-induced cytoskeletal rearrangement relates to vacuolar dynamics and execution of cell death: In vivo imaging of hypersensitive cell death in tobacco BY-2 cells
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DOI：
10.1093/pcp/pcm109
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发表时间：
2007-10-01
影响因子：
4.9
通讯作者：
Kuchitsu, Kazuyuki
中科院分区：
文献类型：
--
作者：
Higaki, Takumi;Goh, Tatsuaki;Kuchitsu, Kazuyuki
液泡膜（VM）的崩解被认为是植物中各种类型的程序性细胞死亡（PCD）的关键事件。然而，其调控机制大多未知。为了获得关于超敏细胞死亡过程中 VM 崩解调节的新见解，我们研究了 VM 的结构动力学和渗透性，以及由蛋白质激发子 Cryptogein 诱导的烟草 BY-2 细胞 PCD 过程中的细胞骨架重组。通过连续观察，我们在 PCD 期间发现了以下显着事件。第一阶段：液泡腔内出现球状VM结构，皮质微管被破坏，而皮质肌动蛋白微丝被捆绑。同时，包括内质微管和肌动蛋白微丝在内的跨液泡链逐渐被破坏，细胞核从细胞中心移动到外围。第2阶段：皮质肌动蛋白微丝束和复杂的球状VM结构消失。中央大液泡的结构变得简单，出现小球形液泡。第 3 阶段：VM 解体，荧光染料 BCECF 在 PCD 之前从液泡中泄漏出来。肌动蛋白聚合抑制剂的应用促进了球状液泡膜结构的消失和细胞死亡的诱导。这些结果表明，激发子诱导的肌动蛋白微丝重组通过改变液泡结构诱导 VM 崩解参与了过敏细胞死亡的调节。
Disintegration of the vacuolar membrane (VM) has been proposed to be a crucial event in various types of programmed cell death (PCD) in plants. However, its regulatory mechanisms are mostly unknown. To obtain new insights on the regulation of VM disintegration during hypersensitive cell death, we investigated the structural dynamics and permeability of the VM, as well as cytoskeletal reorganization during PCD in tobacco BY-2 cells induced by a proteinaceous elicitor, cryptogein. From sequential observations, we have identified the following remarkable events during PCD. Stage 1: bulb-like VM structures appear within the vacuolar lumen and the cortical microtubules are disrupted, while the cortical actin microfilaments are bundled. Simultaneously, transvacuolar strands including endoplasmic microtubules and actin microfilaments are gradually disrupted and the nucleus moves from the center to the periphery of the cell. Stage 2: cortical actin microfilament bundles and complex bulb-like VM structures disappear. The structure of the large central vacuole becomes simpler, and small spherical vacuoles appear. Stage 3: the VM is disintegrated and a fluorescent dye, BCECF, leaks out of the vacuoles just prior to PCD. Application of an actin polymerization inhibitor facilitates both the disappearance of bulb-like vacuolar membrane structures and induction of cell death. These results suggest that the elicitor-induced reorganization of actin microfilaments is involved in the regulation of hypersensitive cell death via modification of the vacuolar structure to induce VM disintegration.