title: [1H]Spin-echo nuclear magnetic resonance in plant tissue. I. The effect of Mn(II) and water content in wheat leaves.
abstract: The effect of age-dependent Mn(II)-gradients, as observed by electron paramagnetic resonance (EPR), on the [1H]NMR spin-spin relaxation time (T2) was studied in wheat leaves. A non-exponential T2 spin-echo decay was always observed, revealing the presence of at least two different fractions of non- (or slowly) exchanging water in the leaves. No effect of the Mn(II)-concentration on T2 of the separate water fractions (covering approximately 90% of the total water content) has been found. From these observations we conclude that Mn(II) is present in bound form. The dependence of T2 on water content can be explained with a two-state model, demonstrating the occurrence of fast exchange within each of the two slowly exchanging water fractions.
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D009682:Magnetic Resonance Spectroscopy; D008345:Manganese / Q000032:analysis*; D063245:Plant Development; D014908:Triticum / Q000254:growth & development; D014867:Water / Q000032:analysis
chemical_list: D014867:Water; D008345:Manganese