<sup>1</sup>H and<sup>31</sup>P NMR investigation of gadolinium uptake in maize roots
Quiquampoix H., Ratcliffe RG., Ratković S., Ratković S., Vučinić Z.
Low-resolution1H NMR and high-resolution31P NMR were used to study the absorption of gadolinium (Gd) by the root tissues of maize seedlings. Gd was supplied as either Gd3+or Gd(DTPA)2-, and its presence in the tissue caused changes in the relaxation properties of the tissue water and of various phosphorylated metabolites.1H NMR relaxation measurements indicated that soluble Gd accumulated in the tissue more rapidly with Gd(DTPA)2-than with Gd3+, and this was attributed to the precipitation of Gd3+in the root. Electron microscopy and x-ray microanalysis confirmed the presence of deposits containing Gd and phosphorus (P) in the extracellular space of the tissue.31P NMR showed the presence of soluble Gd in both the cytoplasm and the vacuole of roots treated with Gd3+and, thus, proved that Gd3+can reach the symplast, contrary to the usual assumption about the lanthanides. Evidence for the immobilization of P by Gd3+and for the vacuolar breakdown of Gd(DTPA)2-was also obtained from the31P NMR spectra. © 1990.