The mode of transmission of signals between plant cells is an important aspect of plant physiology. The main role in generation of long-distance signals is played by changes in the membrane potential and cytoplasm calcium concentration, but the relation between these responses evoked by the same stimuli in the same plant remains unknown. As one of the first plant which colonized lands, the moss Physcomitrella patens is a suitable model organism for studying the evolution of signaling pathways in plants. Here, by application of glutamate as a stimulus, we demonstrated that electrical but not calcium signals can be true carriers of information in long-distance signaling in Physcomitrella. Generation of electrical signals in a form of propagating transient depolarization seems to be dependent on the opening of calcium channels, since the responses were reduced or totally blocked by calcium channel inhibitors. While the microelectrode measurements demonstrated transmission of electric signals between leaf cells and juvenile cells (protonema), the fluorescence imaging of cytoplasmic calcium changes indicated that calcium response occurs only locally - at the site of glutamate application, and only in protonema cells. This study indicates different involvement of glutamate-induced electrical and calcium signals in cell-to-cell communication in these evolutionarily old terrestrial plants.

中文翻译：

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苔藓小草中谷氨酸诱导的电信号和钙信号。

植物细胞之间信号的传输方式是植物生理学的重要方面。远距离信号产生的主要作用是通过膜电位和细胞质钙浓度的变化来实现的，但是同一植物中相同刺激物引起的这些反应之间的关系仍然未知。作为最早定居的植物之一，苔藓小叶藓（Physcomitrella patens）是一种合适的模式生物，可用于研究植物信号传导途径的演变。在这里，通过应用谷氨酸作为刺激，我们证明了电信号而不是钙信号可以是Physcomitrella远距离信号传递中真正的信息载体。电信号以传播性瞬态去极化的形式产生似乎依赖于钙通道的开放，因为反应被钙通道抑制剂降低或完全阻断。尽管微电极的测量表明了叶细胞和幼体细胞（protonema）之间的电信号传输，但细胞质钙变化的荧光成像表明钙反应仅局部发生-在谷氨酸施用部位，并且仅在protonema细胞中发生。这项研究表明，在这些具有进化历史的陆生植物中，谷氨酸诱导的电信号和钙信号参与了细胞间的通讯。