Yu Qin, Ren Jing-Jing, Kong Lan-Jing, Wang Xiu-Ling
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China.
Protoplasma. 2018 Jan;255(1):235-245. doi: 10.1007/s00709-017-1149-1. Epub 2017 Aug 13.
During the opening and closing of stomata, guard cells undergo rapid and reversible changes in their volume and shape, which affects the adhesion of the plasma membrane (PM) to the cell wall (CW). The dynamics of actin filaments in guard cells are involved in stomatal movement by regulating structural changes and intracellular signaling. However, it is unclear whether actin dynamics regulate the adhesion of the PM to the CW. In this study, we investigated the relationship between actin dynamics and PM-CW adhesion by the hyperosmotic-induced plasmolysis of tobacco guard cells. We found that actin filaments in guard cells were depolymerized during mannitol-induced plasmolysis. The inhibition of actin dynamics by treatment with latrunculin B or jasplakinolide and the disruption of the adhesion between the PM and the CW by treatment with RGDS peptide (Arg-Gly-Asp-Ser) enhanced guard cell plasmolysis. However, treatment with latrunculin B alleviated the RGDS peptide-induced plasmolysis and endocytosis. Our results reveal that the actin depolymerization is involved in the regulation of the PW-CW adhesion during hyperosmotic-induced plasmolysis in tobacco guard cells.
在气孔开闭过程中，保卫细胞的体积和形状会发生快速且可逆的变化，这会影响质膜（PM）与细胞壁（CW）的黏附。保卫细胞中肌动蛋白丝的动态变化通过调节结构变化和细胞内信号传导参与气孔运动。然而，目前尚不清楚肌动蛋白动态变化是否调节质膜与细胞壁的黏附。在本研究中，我们通过高渗诱导烟草保卫细胞质壁分离，研究了肌动蛋白动态变化与质膜-细胞壁黏附之间的关系。我们发现，在甘露醇诱导的质壁分离过程中，保卫细胞中的肌动蛋白丝发生了解聚。用Latrunculin B或jasplakinolide处理抑制肌动蛋白动态变化，以及用RGDS肽（Arg-Gly-Asp-Ser）处理破坏质膜与细胞壁之间的黏附，均增强了保卫细胞质壁分离。然而，用Latrunculin B处理可减轻RGDS肽诱导的质壁分离和内吞作用。我们的结果表明，在高渗诱导烟草保卫细胞质壁分离过程中，肌动蛋白解聚参与了质膜-细胞壁黏附的调节。
