Figure 4.

Cytosolic pH dynamics in root tip cells in response to 0-calcium treatment. A, pH dynamics in pH-GFP root tip cells of the region indicated in the schematic drawing, treated with medium with 0-calcium (from 1.5 mM calcium to 0-calcium) as indicated by the black box on the x-axis. The ratio corresponds to the emission of the pH-GFP sensor when excited with light at 405 nm divided by the emission of the sensor when excited at 488 nm. B, The amplitude of 405/488 ratio in 1.5 mM calcium and 0-calcium. n = ≥5. The shaded left-side arrow indicates the direction of the pH decrease. Data were plotted as box-and-whisker plots using GraphPad, in which all the experimental points are plotted, and their distribution represented as a box that extends from the 25th to 75th percentiles. The line in the middle of the box is plotted at the median. P values were calculated with an unpaired Student’s t test. Error bars = sd. ***P ≤ 0.0005 (t test).