High-resolution imaging of cytoplasmic Ca2+ dynamics in Arabidopsis roots

This protocol describes a method for imaging cytoplasmic Ca(2+) dynamics in roots with high resolution using confocal laser scanning microscopy (CLSM). The Förster (fluorescence) resonance energy transfer (FRET)-based genetically modified Ca(2+) indicator Yellow Cameleon YC3.6, stably expressed in plants under the control of the ubiquitin promoter UBQ10, is used for Ca(2+) measurements. This protocol enables imaging of 5- to 7-d-old seedlings with high-magnification objectives (25×, 40×, and 63×).