Figure 4. Cross polarization ¹⁵N NMR spectra of seedling leaves and roots indicating qualitative differences between the two chase times (2 hour and 7 day).

The 7 day chase samples had experienced 2 pulses while the 2 hour samples had 3 pulse of ¹³CO₂. Common integral regions representing the different magnetic environments of nitrogen are shown on the spectra. The asterisks indicate spinning side bands.