Protoplasma

, Volume 194, Issue 1, pp 54–62

Quantitative evaluation of NMR and MRI methods to measure sucrose concentrations in plants

  • T. Y. Tse
  • R. M. Spanswick
  • L. W. Jelinski
Article

DOI: 10.1007/BF01273167

Cite this article as:
Tse, T.Y., Spanswick, R.M. & Jelinski, L.W. Protoplasma (1996) 194: 54. doi:10.1007/BF01273167

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.

Keywords

Nuclear magnetic resonanceMagnetic resonance imagingPisum sativum L.SucroseWater suppression

Abbreviations

CD-CHESS

continuous wave decoupling chemical shift selective imaging

CHESS

chemical shift selective imaging

CSI

chemical shift imaging

CW

continuous wave

DQF

homonuclear double quantum filtering

FOV

field of view

FW

fresh weight

GHMQC

gradient version of the heteronuclear multiple quantum coherence

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • T. Y. Tse
    • 1
    • 2
  • R. M. Spanswick
    • 2
  • L. W. Jelinski
    • 1
  1. 1.Center for Advanced Technology in BiotechnologyCornell UniversityIthacaUSA
  2. 2.Section of Plant Biology, Division of Biological SciencesCornell UniversityIthaca