Figure 3.

NanoSIMS ion images highlighting in situ spatial relationships, coupled with levels of ¹⁵N enrichment. A to C, Overlays of ¹²C¹⁴N (yellow) and ²⁸Si (blue) ion images representative of key regions: plant root cells (A), rhizosphere (B), and soil matrix (C). A root hair that has encountered a soil particle and diverged is seen in B (arrow). D to F, ¹⁵N/¹⁴N ratio images from same regions, showing areas of ¹⁵N enrichment. The color depicts the ¹⁵N/¹⁴N ratio, with the ratio scale shown in F. Bar = 5 μm. G to I, Overlay of ¹²C¹⁴N (yellow), ²⁸Si (blue), and ¹²C¹⁵N/¹²C¹⁴N (red) images from each region.