Figure 8.
Mapping of fractions of magnesium, potassium, and calcium, originating from the tracer solution, in samples taken after 240 min of continuous tracer application via the cut stem. A, Cryo-SEM image with color-coded overlay to show tissue types: thick-walled xylem parenchyma (green) and cambium (orange). Asterisks indicate immature vessels, and the white arrowhead indicates thin-walled xylem parenchyma within thick-walled parenchyma. B to D, Fractions of tracer (FMg, FK, FCa) are scaled from zero to the indicated maxima. For better visualization, pixels below the following thresholds of the scale (indicated by white lines in the color bars) were set transparent: FMg and FCa, 6%; FK, 2%. Area scanned by cryo-SIMS was 500 × 500 μm2, 256 × 256 pixels.