Figure 4.

Application of Auxin and ATP Triggers Spatiotemporally Overlapping Cytosolic Concentration Changes of Ca²⁺, H⁺, and Cl^–.

Analyses of roots of 5-d-old Arabidopsis expressing R-GECO1-GSL-E²GFP (Ca²⁺, pH, and Cl^–) in response to 1 µM IAA (t = 0 min) and 1 mM ATP (t = 40 min; n = 6). Images were acquired for 84 min at a frame rate of 10 min⁻¹.

(A) Average vertical response profiles of (top) fluorescence emissions (F) or emission ratios (R). (Middle) Signal changes (ΔF/F₀ or ΔR/R₀) normalized to 4-min average baseline recordings. (Bottom) Full image signal changes (mean ± sd).

(B) Spatiotemporal Pearson correlation analyses (mean ± sd) of indicated GEFI responses during the application of IAA (t = –4 to 15 min). An adjacent representative bright field (BF) root image is shown for orientation.

A representative experiment is provided as Supplemental Movie 4.