Figure 5.

A, An ion intensity image of ⁸⁵Rb in the top half of a 20-µm-thick cross section from Arabidopsis roots, analyzed by LA-ICP-MS with 1.4 J cm⁻² in the laser beam. B, An ion intensity map of ⁸⁵Rb in the bottom half of the same section as in A, analyzed with 0.6 J cm⁻² in the laser beam. C, An ⁸⁵Rb ion intensity map analyzed with 2.4 J cm⁻² in the laser beam. D, An ion intensity map of ⁶⁶Zn from the same cross section as in C. E, The distribution and ion intensity of ⁶⁶Zn in the same cross section as in C, where the values have been corrected, using the ⁸⁵Rb signal as an internal standard. The color spectrum represents high to low ion intensities (for ⁸⁵Rb, range, 10–5,000 counts [A–C]; for ⁶⁶Zn, range, 0–150 counts [D and E]). Bars = 50 µm.