The reorganization of actin filaments is required for vacuolar fusion of guard cells during stomatal opening in Arabidopsis
The reorganization of actin filaments is required for vacuolar fusion of guard cells during stomatal opening in Arabidopsis
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DOI：
10.1111/j.1365-3040.2012.02592.x
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发表时间：
2013-02-01
影响因子：
7.3
通讯作者：
Wang, Xue-Chen
中科院分区：
文献类型：
--
作者：
Li, Li-Juan;Ren, Fei;Wang, Xue-Chen
保卫细胞中肌动蛋白丝（AF）和液泡的重组参与气孔运动的调节。然而，目前尚不清楚 AF 重组与气孔运动过程中液泡变化之间是否存在相互作用。在这里，我们报告了药理学实验中揭示的 AF 重组和液泡融合之间的关系，并描述了肌动蛋白相关蛋白 2 (arp2) 和 arp3 突变体的气孔开放特征。我们的结果表明，细胞松弛素-D 诱导的解聚或鬼笔环肽诱导的 AF 稳定会导致野生型 (WT) 拟南芥植物气孔开放期间未融合的小空泡增加。突变体中光诱导的气孔开放迟缓，保卫细胞空泡融合受损，AF的重组和动态参数与WT相比出现异常。在 WT 中，AF 紧紧围绕着小的分离液泡，形成一个环，围绕气孔开放期间部分融合的液泡边界膜。相反，在突变体中，大多数 AF 和肌动蛋白斑块在保卫细胞核周围异常积累，这可能进一步损害液泡融合并延迟气孔开放。我们的结果表明，AF 的重组在气孔开放期间调节保卫细胞中的液泡融合。
The reorganization of actin filaments (AFs) and vacuoles in guard cells is involved in the regulation of stomatal movement. However, it remains unclear whether there is any interaction between the reorganization of AFs and vacuolar changes during stomatal movement. Here, we report the relationship between the reorganization of AFs and vacuolar fusion revealed in pharmacological experiments, and characterizing stomatal opening in actin-related protein 2 (arp2) and arp3 mutants. Our results show that cytochalasin-D-induced depolymerization or phalloidin-induced stabilization of AFs leads to an increase in small unfused vacuoles during stomatal opening in wild-type (WT) Arabidopsis plants. Light-induced stomatal opening is retarded and vacuolar fusion in guard cells is impaired in the mutants, in which the reorganization and the dynamic parameters of AFs are aberrant compared with those of the WT. In WT, AFs tightly surround the small separated vacuoles, forming a ring that encircles the boundary membranes of vacuoles partly fused during stomatal opening. In contrast, in the mutants, most AFs and actin patches accumulate abnormally around the nuclei of the guard cells, which probably further impair vacuolar fusion and retard stomatal opening. Our results suggest that the reorganization of AFs regulates vacuolar fusion in guard cells during stomatal opening.