1H-NMR spin-spin relaxation time assessment of the reflection coefficient of the Triticale seed cell wall-plasmalemma barrier to mannitol. [Erratum: July 1997, v. 20 (7), p. 967-968.]

• Published in: Plant, cell and environment Vol. 19; no. 12; pp. 1443 - 1448
• Main Authors: Miedziejko, E.M, Plenzler, G.B, Napierala, D.M, Narozna, A.T
• Format: Journal Article
• Language: English
• Published: 01.12.1996
• Subjects: cell walls; diffusion; imbibition; mannitol; membrane permeability; nuclear magnetic resonance spectroscopy; permeability; plasma membrane; seeds; triticale; uptake; water uptake
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/j.1365-3040.1996.tb00024.x

The 1H-NMR spin-spin relaxation time (T2) in Triticale seeds swelling in external osmotica, polyethylene glycol 8000 or mannitol can identify both bound and free water. At the same water content, the free water spin-spin relaxation time increases for seeds imbibed with the mannitol solution, demonstrating inadequate water potential adjustment. The exchange rate of free/bound water molecules is apparently influenced by the driving force for water flow. The reciprocal lifetime of free water molecules, as a measure of water flow through the main cell barrier, was obtained. From a model of the seed as a resistance-capacitor network for water flow, a method was derived for calculating the reflection coefficient sigma as a lifetime ratio of the free water molecules in seeds imbibed with two different osmotica (one penetrating across the main cell barrier and one not penetrating) at the same water potential. The 1H-NMR method and the classical method based on volume rate changes yielded reflection coefficients for mannitol for the cell wall-plasmalemma barrier of 0.78 +/- 0.08 and 0.68 +/- 0.06, respectively.