Using Bulk Magnetic Susceptibility to Resolve Internal and External Signals in the NMR Spectra of Plant Tissues

✍ Scribed by Yair Shachar-Hill; Douglas E Befroy; Philip E Pfeffer; R.George Ratcliffe

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 514 KB
• Volume: 127
• Category: Article
• ISSN: 1090-7807
• DOI: 10.1006/jmre.1997.1185

✦ Synopsis

Internal and external NMR signals from a variety of plant cells between internal and external compartments (5-7). The first and plant tissues can be resolved by changing the bulk magnetwo of these mechanisms lack generality with regard to the tic susceptibility (BMS) of the perfusing medium with [Gd observed species, for example, paramagnetic shift reagents (EDTA)] 0 or Dy(DTPA-BMA). This separation is observed in are rarely useful for the in vivo discrimination of the signals samples consisting of cylindrical cells oriented along the B 0 field, from neutral molecules, and it is perhaps only the third that and is consistent with established theoretical predictions about offers the opportunity to resolve internal and external signals BMS effects. Evidence is presented that the shifted signals reprefrom the full range of detectable ions and metabolites. Unforsent material outside the tissue as well as some contribution from tunately susceptibility effects are critically dependent on intercellular spaces and cell walls, while intracellular signals are sample geometry (6, 8, 9, and references therein) and this unshifted. The paramagnetic complexes used to separate the sig-

imposes severe limitations on their exploitation. Indeed susnals are shown to be nontoxic and to have no effect on a number of transport processes. The method has been applied to roots, ceptibility effects are more usually a complication in NMR, shoots, and giant algal cells, facilitating the interpretation of the and it has only been in rather particular circumstances that in vivo spectra from a range of biologically important magnetic such effects have been exploited (9-11). However for many isotopes. The potential of the method for studies of transport is plant tissues, the regular cylindrical geometry and the permeillustrated with experiments showing: (i) 14 N/ 15 N isotopic exability of the extracellular space suggests that susceptibility change of nitrate in roots; (ii) the influx of HDO into root and reagents could provide an effective method for separating shoot segments; and (iii) the use of saturation transfer to follow internal and external signals. Here we show that complexes water movement into and out of plant cells. ᭧ 1997 Academic Press of gadolinium and dysprosium may be successfully used with perfused root and shoot segments to resolve intracellular and extracellular signals from a range of small molecules.