Gradient NMR Method for Studies of Water Translational Diffusion in Plants.

The review of a retrospective nature shows the stages of development of the spin-echo NMR method with constant and pulsed gradient of the magnetic field (gradient NMR) for the study of water diffusion in plant roots. The history of the initial use of gradient NMR for plants, in which it was not possible to experimentally confirm the bound state of water in cells, is described. The work presents the main ideas on which the technology of measuring diffusion by the spin-echo NMR method is built. Special attention is paid to the manifestations and record of the restricted diffusion phenomenon, permeability of membranes, along with the finite formulae used in real experiments. As examples, it gives the non-trivial results of studies of water transfer in roots through the symplastic system, from cell to cell through intercellular contacts with plasmodesmata, through aquaporins, transfer under the influence of changes in external pressure, and the composition of the gas atmosphere.