Gao Xin-Qi, Chen Jing, Wei Peng-Cheng, Ren Fei, Chen Jia, Wang Xue-Chen
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University 100094, Beijing, People's Republic of China.
Plant Cell Rep. 2008 Oct;27(10):1655-65. doi: 10.1007/s00299-008-0581-2. Epub 2008 Jul 9.
Actin filaments in guard cells and their dynamics function in regulating stomatal movement. In this study, the array and distribution of actin filaments in guard cells during stomatal movement were studied with two vital labeling, microinjection of alexa-phalloidin in Vicia faba and expression of GFP-mTn in tobacco. We found that the random array of actin filaments in the most of the closed stomata changed to a ring-like array after stomatal open. And actin filaments, which were throughout the cytoplasm of guard cells of closed stomata (even distribution), were mainly found in the cortical cytoplasm in the case of open stomata (cortical distribution). These results revealed that the random array and even distribution of actin filaments in guard cells may be required for keeping the closed stomata; similarly, the ring-like array and cortical distribution of actin filaments function in sustaining open stomata. Furthermore, we found that actin depolymerization, the trait of moving stomata, facilitates the transformation of actin array and distribution with stomatal movement. So, the depolymerization of actin filaments was favorable for the changes of actin array and distribution in guard cells and thus facilitated stomatal movement.
保卫细胞中的肌动蛋白丝及其动态变化在调节气孔运动中发挥作用。在本研究中，利用两种活体标记方法，即对蚕豆微注射藻红蛋白和在烟草中表达绿色荧光蛋白 - 肌钙蛋白，研究了气孔运动过程中保卫细胞内肌动蛋白丝的排列和分布。我们发现，大多数关闭气孔中随机排列的肌动蛋白丝在气孔张开后转变为环状排列。并且，在关闭气孔的保卫细胞整个细胞质中（均匀分布）的肌动蛋白丝，在气孔张开时主要位于皮层细胞质中（皮层分布）。这些结果表明，保卫细胞中肌动蛋白丝的随机排列和均匀分布可能是维持气孔关闭所必需的；同样，肌动蛋白丝的环状排列和皮层分布在维持气孔张开中起作用。此外，我们发现肌动蛋白解聚，即气孔运动的特征，促进了肌动蛋白排列和分布随气孔运动的转变。因此，肌动蛋白丝的解聚有利于保卫细胞中肌动蛋白排列和分布的变化，从而促进气孔运动。
