Fig. 3

Confocal images and CF transients on different spatial scales inside a living leaf. A 633-nm laser, with 3 kW/cm² intensity, is adopted for 50 s continuous confocal imaging. The sample leaf was kept in darkness for ~20 min before imaging. a1 The image over a large area of the leaf, a2 zoomed into show a group of palisade cells, and a3 further zoomed into focus onto a single chloroplast. b1, b2 CF transient from a group of palisade cells and a single chloroplast, respectively. b2 Noisier since less pixels are involved