Cryptochrome, Calcium Waves and Side-Branch Formation in P. patens

光激活了一系列特定的光感受器，启动了一系列复杂的信号转导事件，导致植物的发育、生理和生化发生戏剧性的变化。至少有三类光感受器(隐色素、趋光素、光敏色素)参与感知环境光条件。光敏色素在红色和远红色区域吸收，而隐色素和光敏素则在蓝色和UV-A区域吸收。虽然钙离子已被认为是许多信号通路中的关键第二信使，但它在单个植物细胞的光感受器信号转导中的作用尚未确定。在之前的一项研究中，使用Fura 2进行的钙比成像被用来测量暗生长的小球藻茎细胞中的细胞质钙。幸运的是，需要量化钙的UV-A光刺激了光感受器系统，使这种方法成为研究钙在光感受器信号中所起作用的重要手段。我们已经获得了不含隐花色素基因的P.patens突变体。将在这些植物中研究钙信号和侧枝形成，以确定钙作为第二信使在隐花色素信号转导中的作用。

Light activates a series of specific photoreceptors and initiates a complex series of signal transduction events that result in dramatic developmental, physiological, and biochemical changes in the plant. At least three classes of light receptors (cryptochromes, phototropins, phytochromes) are involved in sensing the ambient light conditions. While phytochromes absorb in the red and far red regions, cryptochromes and phototropins absorb in the blue and UV-A regions. Although Ca2+ has been identified as a key second messenger in many signaling pathways, its role in photoreceptor signaling in a single plant cell has not been established. In a previous study, calcium ratio imaging using Fura 2 was used to measure cytoplasmic calcium in dark-growing caulonemal cells of the moss Physcomitrella patens. Fortuitously, the UV-A light needed to quantify calcium stimulated the photoreceptor system, making this approach an important means to study the role that calcium plays in photoreceptor signaling. P. patens mutants that are without cryptochrome genes have been made available to us. Calcium signaling and side branch formation will be examined in these plants to determine the role of calcium as a second messenger in cryptochrome signal transduction.