Fig. 6.

Distinct cytosolic and nuclear Ca²⁺- and H⁺-signatures in mesophyll cells upon different stimuli. Simultaneous Ca²⁺, H⁺ and V_m recordings in mesophyll cells of Nicotiana benthamiana leaves transiently expressing a cytosolic or nuclear version of the CapHensor. (a, e) Representative brightfield (left) as well as false colored [H⁺]- (middle) and [Ca²⁺] (right) ratio images of a leave mesophyll section expressing the (a) cytosolic- or (e) nuclear CapHensor version. (b–d) Mean [Ca²⁺]_cyt ratio (red), [H⁺]_cyt ratio (green) and membrane potential (V_m, black) dynamics over time upon application of (b) 100 nM flg22 (n = 9), (c) 25 μM ABA (n = 6) and (d) 200 μM H₂O₂ (n = 5). (f–h) Mean [Ca²⁺]_nuc ratio (red), [H⁺]_nuc ratio (green) and V_m (black) dynamics over time upon application of (f) 100 nM flg22 (n = 6), (g) 25 lM ABA (n = 4) and (h) 200 μM H₂O₂ (n = 5). (i, j) Bar diagram of mean onset and peak times of Ca²⁺ ratio (red), H⁺ ratio (green) and V_m after 100 nM flg22 with the cytosolic (i) or nuclear (j) expressed CapHensor. (k) Bar diagram of mean membrane potential (V_m) in mesophyll cells at the onset (left) and peak (right) response when the cytosol (blank, n = 9) or nucleus (shadow, n = 6) expressed version for CapHensor was used. Error bars = SE. Dots in (i–k) indicate individual measurements. One-way ANOVA was used in (i) and (j). *, P < 0.05; ***, P < 0.001.