ISSN:
1615-6102
Keywords:
Nuclear magnetic resonance
;
Magnetic resonance imaging
;
Pisum sativum L.
;
Sucrose
;
Water suppression
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Developing pea (Pisum sativum L.) seeds were chosen to evaluate the performance of various nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) methods of detecting sucrose in plants. The methods included chemical shift selective imaging (CHESS), heteronuclear correlation via13C-1H coupling (HMQC), and homonuclear correlation via1H-1H coupling (DQF). The same experiments were also performed on sucrose phantom samples to evaluate the methods in the absence of the line broadening observed in plant systems. Using the spin echo technique for multi-slice imaging, we could discern the detailed internal structure of the intact seed with a resolution of tens of microns. The proton spin-lattice relaxation time and linewidth as a function of the age of the seed were measured to optimize the efficiency of the NMR and MR experiments. The age-dependent changes in these NMR parameters are consistent with the accumulation of insoluble starch as age increases. Both the NMR and MRI results are in accord with the results of chemical analysis, which reveal that the sucrose concentration is higher in the embryo than in the seed coat, and glucose is at low concentration throughout the seed. Of the three methods for proton observation, the enhanced version of the CHESS approach (CD-CHESS) provides the best combination of sucrose detection and water suppression. Direct observation of13C is preferable to indirect detection using HMQC because of water signal bleed-through in samples with large (〉200 Hz) linewidths.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01273167
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