Tang Ru-Hang, Han Shengcheng, Zheng Hailei, Cook Charles W, Choi Christopher S, Woerner Todd E, Jackson Robert B, Pei Zhen-Ming
Department of Biology, Duke University, Durham, NC 27708, USA.
Science. 2007 Mar 9;315(5817):1423-6. doi: 10.1126/science.1134457.
Various signaling pathways rely on changes in cytosolic calcium ion concentration ([Ca2+]i). In plants, resting [Ca2+]i oscillates diurnally. We show that in Arabidopsis thaliana, [Ca2+]i oscillations are synchronized to extracellular Ca2+ concentration ([Ca2+]o) oscillations largely through the Ca2+-sensing receptor CAS. CAS regulates concentrations of inositol 1,4,5-trisphosphate (IP3), which in turn directs release of Ca2+ from internal stores. The oscillating amplitudes of [Ca2+]o and [Ca2+]i are controlled by soil Ca2+ concentrations and transpiration rates. The phase and period of oscillations are likely determined by stomatal conductance. Thus, the internal concentration of Ca2+ in plant cells is constantly being actively revised.
各种信号通路依赖于胞质钙离子浓度（[Ca2+]i）的变化。在植物中，静息[Ca2+]i呈昼夜振荡。我们发现，在拟南芥中，[Ca2+]i振荡在很大程度上通过钙离子感应受体CAS与细胞外钙离子浓度（[Ca2+]o）振荡同步。CAS调节肌醇1,4,5-三磷酸（IP3）的浓度，而IP3又指导从内部储存库中释放钙离子。[Ca2+]o和[Ca2+]i的振荡幅度受土壤钙离子浓度和蒸腾速率控制。振荡的相位和周期可能由气孔导度决定。因此，植物细胞内钙离子的浓度在不断地被积极调整。
