Abstract
1H NMR relaxation times (T1 and T2) in parenchyma tissue of apple can identify three populations of water with different relaxation characteristics. By following the uptake of Mn2+ ions in the tissue it is shown that the observed relaxation times originate from particular water compartments: the vacuole, the cytoplasm, and the cell wall/extracellular space.
Proton exchange between these compartments is controlled by the plasmalemma and tonoplast membranes. During the Mn2+ penetration experiment, conditions occur that cause the relaxation times of protons of cytoplasmic water to be much shorter than their residence time in the cytoplasm. Then the tonoplast permeability coefficient Pd for water can be calculated from the vacuolar T1 and T2 values to be 2.44 10-5 m·s-1.
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- Bacić G., Ratković S. Water exchange in plant tissue studied by proton NMR in the presence of paramagnetic centers. Biophys J. 1984 Apr;45(4):767–776. doi: 10.1016/S0006-3495(84)84220-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Conlon T., Outhred R. Water diffusion permeability of erythrocytes using an NMR technique. Biochim Biophys Acta. 1972 Nov 2;288(2):354–361. doi: 10.1016/0005-2736(72)90256-8. [DOI] [PubMed] [Google Scholar]
- Hills B. P., Duce S. L. The influence of chemical and diffusive exchange on water proton transverse relaxation in plant tissues. Magn Reson Imaging. 1990;8(3):321–331. doi: 10.1016/0730-725x(90)90106-c. [DOI] [PubMed] [Google Scholar]
- Stout D. G., Steponkus P. L. Nuclear magnetic resonance relaxation times and plasmalemma water exchange in ivy bark. Plant Physiol. 1978 Oct;62(4):636–641. doi: 10.1104/pp.62.4.636. [DOI] [PMC free article] [PubMed] [Google Scholar]
- van As H., Brouwers A. A., Snaar J. E. Localized real time blood flow measurements. Arch Int Physiol Biochim. 1985 Dec;93(5):87–95. doi: 10.3109/13813458509080629. [DOI] [PubMed] [Google Scholar]
- van As H., van Vliet W. P., Schaafsma T. J. [1H]Spin-echo nuclear magnetic resonance in plant tissue. I. The effect of Mn(II) and water content in wheat leaves. Biophys J. 1980 Dec;32(3):1043–1049. doi: 10.1016/S0006-3495(80)85035-1. [DOI] [PMC free article] [PubMed] [Google Scholar]