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

光激活一系列特定的光感受器，并启动一系列复杂的信号转导事件，导致植物发生显著的发育、生理和生化变化。 至少有三类光受体（隐花色素、光亲素、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，隐花色素和向光蛋白在蓝色和UV-A区域吸收。 虽然Ca ~（2+）已被确定为许多信号转导途径中的关键第二信使，但其在单个植物细胞中的感光信号转导中的作用尚未确定。 在以前的研究中，钙比率成像使用Fura 2被用来测量暗生长的茎生细胞的苔藓小立碗藓细胞质钙。 幸运的是，量化钙所需的UV-A光刺激了感光系统，使这种方法成为研究钙在感光器信号传导中作用的重要手段。 没有隐花色素基因的展叶假单胞菌突变体已经提供给我们。 钙信号和侧分支的形成将在这些植物中进行检查，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.