Institute for Integrative Genome Biology, University of California, Riverside, 92521 California, USA.
Department of Botany and Plant Sciences, University of California, Riverside, 92521 California, USA.
Plant Physiol. 2022 Mar 28;188(4):2253-2271. doi: 10.1093/plphys/kiac020.
As a universal second messenger, calcium (Ca2+) transmits specific cellular signals via a spatiotemporal signature generated from its extracellular source and internal stores. Our knowledge of the mechanisms underlying the generation of a Ca2+ signature is hampered by limited tools for simultaneously monitoring dynamic Ca2+ levels in multiple subcellular compartments. To overcome the limitation and to further improve spatiotemporal resolutions, we have assembled a molecular toolset (CamelliA lines) in Arabidopsis (Arabidopsis thaliana) that enables simultaneous and high-resolution monitoring of Ca2+ dynamics in multiple subcellular compartments through imaging different single-colored genetically encoded calcium indicators. We uncovered several Ca2+ signatures in three types of Arabidopsis cells in response to internal and external cues, including rapid oscillations of cytosolic Ca2+ and apical plasma membrane Ca2+ influx in fast-growing Arabidopsis pollen tubes, the spatiotemporal relationship of Ca2+ dynamics in four subcellular compartments of root epidermal cells challenged with salt, and a shockwave-like Ca2+ wave propagating in laser-wounded leaf epidermis. These observations serve as a testimony to the wide applicability of the CamelliA lines for elucidating the subcellular sources contributing to the Ca2+ signatures in plants.
钙（Ca2+）作为一种普遍的第二信使，通过其细胞外来源和内部储存产生的时空特征来传递特定的细胞信号。我们对产生 Ca2+特征的机制的了解受到用于同时监测多个亚细胞区室中动态 Ca2+水平的有限工具的限制。为了克服这一限制并进一步提高时空分辨率，我们在拟南芥（Arabidopsis thaliana）中组装了一个分子工具集（CamelliA 系），通过成像不同的单染基因编码钙指示剂，能够同时和高分辨率监测多个亚细胞区室中的 Ca2+动力学。我们在三种类型的拟南芥细胞中发现了几种 Ca2+特征，以响应内部和外部信号，包括快速生长的拟南芥花粉管中细胞质 Ca2+的快速振荡和顶端质膜 Ca2+内流、盐胁迫下根表皮细胞四个亚细胞区室 Ca2+动力学的时空关系，以及激光损伤的叶片表皮中传播的类冲击波状 Ca2+波。这些观察结果证明了 CamelliA 系在阐明植物中 Ca2+特征的亚细胞来源方面的广泛适用性。
