CamelliA-based simultaneous imaging of Ca2+ dynamics in subcellular compartments

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 generation of a Ca2+ signature is hampered by limited tools enabling simultaneous monitoring of the dynamics of Ca2+ levels in multiple subcellular compartments. To overcome the limitation and to further improve spatiotemporal resolutions, here we have assembled a molecular toolset (the CamelliA lines) in Arabidopsis that enables simultaneous and high-resolution monitoring of Ca2+ dynamics in multiple subcellular compartments through imaging analyses of different single-colored GECIs (Genetically Encoded Calcium Indicators). Indeed, the uncovering of the previously unrecognized Ca2+ signatures in three types of Arabidopsis cells in response to internal and external cues is a testimony to the wide applicability of the newly generated toolset for elucidating the subcellular sources contributing to the Ca2+signatures in plants. One sentence summaryA toolset for simultaneous imaging of Ca2+ dynamics in subcellular compartments has uncovered unrecognized Ca2+ signatures in Arabidopsis cells in response to developmental and external cues.