Measuring of water transport selectively along the plant root plasmodesmata using gradient nuclear magnetic resonance with paramagnetic doping.

In this study, we measured translational water diffusion selectively along symplast pathway through plasmodesmata in maize roots, and the effective plasmodesmata permeability coefficient (P) was determined using a nuclear magnetic resonance (NMR) spin echo method. Measuring of water transport selectively along the plant root plasmodesmata was achieved with paramagnetic complexes (PCs) of high relaxation efficiency. PCs penetrate into the intercellular space of root tissue, but not into cells, and accelerate the magnetic relaxation processes of intercellular water, thereby excluding the contribution of intercellular water to the registered NMR diffusion echo attenuation. In result, NMR control of translational diffusion can be applied to the signal of the water moving along the symplast pathway through plasmodesmata, where the PCs do not penetrate. Diethylenetriaminepentaacetic acid (GdDTPA), Mn2+-trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (MnDCTA), and GdCl3 were used as PCs. An increase in the PCs concentration led to a side effect in the form of a varying decrease in diffusive water transport in the roots. The P was determined by extrapolating the concentration dependence to zero concentration of PCs. Among the PCs studied, MnDCTA had the least side effects on the water transport when the concentration dependence was linear. When MnDCTA was used, the P accounted for 30-35% of the total cell water permeability (by transmembrane and symplast pathways). The rate of water flow along the plasmodesmata in the approximation of the piston mode of flow along the linear cell chain was estimated to range from 4.5 × 10-7 to 8.8 × 10-7 m/s.

Growth function and intercellular water transfer in excised roots.

On the example of maize seedling roots, it was shown that segments of the root suction zone excised from intact mother seedlings maintain the function of elongation growth and are able to regulate water transfer. Using the gradient NMR method, the effective intercellular permeability of root suction zone segments was shown to reduce with respect to intact seedling roots. The segment fragmentation into smaller pieces 3 mm long resulted in the permeability decrease by 60%. The reduction is associated with the cell defensive response to water loss through cuts and blocking of the additive water transfer along the segment length, resulting from segment cutting.

BODIPY dyes with thienyl- and dithienylthio-substituents - synthesis, redox and fluorescent properties.

8-Phenyl- and 8-(4-nitrophenyl)-BODIPYs with thien-2-ylthio- and (2,2'-dithien-5-yl)-thio-substitution at the 3,5-positions were synthesized. 2-Thienylthio derivatives were obtained using two different sequences, i.e., via nucleophilic substitution in the corresponding 1,9-dichlorodipyrromethenes, followed by BODIPY formation and via the same reaction using 3,5-dichloro-BODIPY dyes. The "dipyrromethene route" was observed to result in better overall yields. All the dyes were characterized by UV-Vis and fluorescence spectroscopy as well as cyclic voltammetry (CVA) studies. The UV-Vis spectra exhibited slight dependence on the thiophene chain length. The thienylthio derivatives fluoresce with modest quantum yields; conversely, no fluorescence has been detected for their dithienylthio counterparts. 8-Phenyl-3,5-di(thien-2-ylthio)-BODIPY was characterized by X-ray crystallography, which showed the layered arrangement of the molecules. The thienyl fragments of different molecules in the same layer form pairs alike H-aggregates, whereas the BODIPYs moieties in the different layers are arranged in a J-aggregate fashion. Solid fluorescence was observed for these crystals with a broad emission from 600 nm to longer than 850 nm. The CVA results correspond to those for known substituted BODIPYs except for the unusually high current observed for the oxidation process of the dithienyl derivatives with respect to the reduction process. This finding indicates oxidative film deposition.

[Effect of hydrostatic pressure on structural organization of the maize root cells].

We analyzed the effect of hydrostatic pressure at 24 MPa level on the growth and organization of corn seedlings cells. At pressure value of 2 MPa, we observed the clarification of the mitochondrial matrix, clusterization of endoplasmic reticulum elements with formation of ergastorplasm sites and the increasing number of small vacuoles in the cytoplasm. We detected the accumulation of vesicles with electron-dense content on the trans side of dictyosomes, which indicates a change in the endomembranous system traffic. The reduction of electronic density of tonoplast was accompanied by a reduction of osmiophilic inclusions in the vacuoles. Increasing the pressure up to 4 MPa showed the emergence of destructive alterations in the tonoplast. None of the variants showed any violation of plasmalemma integrity, as confirmed by coloring with Evans blue. When we reset the hydrostatic pressure to atmospheric pressure, the frequency of structural distortions of the tonoplast membrane was proportional to the pressure difference: the minimum was at reset from 2 to 0 MPa and the maximum was at reset from 4 to 0 MPa. Thus, it has been concluded, that the endomembraneous system is among the targets of pressure effect on the plant cells.

A simple air system for temperature stabilization in the range -10 to +80 degrees C for use in NMR spectroscopy.

This paper proposes a design for a system of temperature stabilization within the range from -10 to +80+/-0.5 degrees C for NMR spectrometers which is simple and affordable to fabricate in a laboratory. The design utilizes a closed system of circulation of an air heat carrier, twofold flow around the thermostabilized system, cooling element on Peltier thermal modules, and a proportional-integral-derivative regulator.

[Paraurethral cyst and/or urethral diverticulum--differential diagnosis].

From 2003 to 2006 we examined and treated 73 females with paraurethral lesions. The differential diagnosis was made using gynecological and US examinations, urethral profilometry, miction cystourethrography, high-pressure urethrography, MR imaging. All the patients have undergone extirpation of paraurethral cyst/diverticulectomy. The diagnosis of paraurethral lesions should be made with application of all available methods. Gynecological examination is the first procedure in complex diagnostic investigation, ultrasound must be also used in all the patients with addition of x-ray in case of insufficient data. MR imaging is used in large size of paraurethral lesions, their connection with urethra. Treatment of such patients is surgical.

[Analysis of diffusion and relaxation behavior of water in apple parenchymal cells].

It has been demonstrated by an example of apple parenchymal cells that NMR spectroscopy can be used to analyze the relaxation and diffusion of water molecules in plant cells. With small diffusion times, three relaxation components have been distinguished, which correspond to water in a vacuole, in the cytoplasm, and in intercellular liquid. The coefficient of self-diffusion corresponding to these components have been determined. With large diffusion times, it is possible to distinguish two components. For the slowly relaxing component (which corresponds to water in a vacuole), the regime of restricted diffusion was observed. For a quickly relaxing component, an anomalous increase in the coefficient of self-diffusion with the time of diffusion took place.

Spin-lattice NMR relaxation by anomalous translational diffusion.

A model-free theoretical framework for a phenomenological description of spin-lattice relaxation by anomalous translational diffusion in inhomogeneous systems based on the fractional diffusion equation is developed. The dependence of the spin-lattice relaxation time on the size of the pores in porous glass Vycor is experimentally obtained and found to agree well with our theoretical predictions. We obtain nonmonotonic behavior of the translational spin-lattice relaxation rate constant (it passes through a maximum) with the variation of the parameter referring to the extent of inhomogeneity of the system.

Contribution of the actomyosin motor to the temperature-dependent translational diffusion of water by cytoplasmic streaming in Elodea canadensis cells.

The extent to which the actomyosin motor responsible for cytoplasmic streaming contributes to the translational diffusion of water in Elodea canadensis cells was studied by a nuclear magnetic resonance (NMR) spin-echo technique. The relative contribution of the actomyosin motor was determined from the corresponding apparent diffusion coefficient by the Einstein-Smolukhovsky relation. It is equal to the difference between the diffusional displacements of the cytoplasmic and the bulk water (deltaX). The NMR data show that the temperature dependence of deltaX is humpshaped, which is characteristic of enzyme reactions. At the same time, the apparent diffusion coefficient of cytoplasmic water increases with an increase in temperature. The most significant contribution of the actomyosin motor to deltaX is observed at temperatures below 20 degrees C. Within the temperature range of 20 to 33 degrees C, deltaX changes only slightly, and a further increase in temperature reduces deltaX to zero.

[The NMR spin-echo method is used for measurements of the translational water diffusion selectively along the apoplast and the vacuolar and cytoplasmic symplasts of plant tissue]. / Metod spin-ékho IAMR v issledovaniiakh transliatsionnoi diffuzii vody selektivno po apoplastu, tsitoplazmaticheskomu i vakuoliarnomu simplastu rastenii.

Simple methods for the registration of translational diffusion of water in apoplast and vacuolar and cytoplasmic symplasts were developed. The methods are based on spin-echo NMR with a pulsed magnetic field gradient and are realized by preliminary inversion of magnetization and the use of paramagnetic doping. It was shown that the diffusion of a part of root water in segments of mais roots is more enhanced than that for the bulk water. The results are explained by the appearance of the rotational movement of the protoplasm and in terms of the hypothesis of water transfer along the apoplast, which balances the cytoplasmic symplast.

Water diffusion in biological porous systems: a NMR approach.

The spin-echo nuclear magnetic resonance (NMR) technique together with paramagnetic ion doping are used to study structural parameters of plant samples, such as restricted dimensions, and cell interconnection both through membranes and by cell contact by studying simultaneous restricted diffusion and intercellular water transfer via various pathways. Also, peculiarities of water diffusion on the surface of cell-wall cellulose are studied over a wide range of water content.

The effect of osmotics on plant cells: a study using 1H NMR relaxation and self-diffusion of water.

The osmotic changes in root cells of Zea mays L. under the effect of mannitol (concentration range 1-15%; range of osmotic pressures: -0.13 to -2.01 MPa) were studied by measuring time and concentration dependence of water self-diffusion constant (Deff) and proton spin-lattice relaxation time (T1) using proton NMR relaxation spectroscopy. In addition, in vivo uptake of Mn2+ by roots after their incubation in mannitol solutions were studied. At low (less than or equal to 5%) and medium (5-10%) concentrations of the osmoticum dehydration takes place proportional to the concentration, whereas membrane destruction occurs at higher concentrations (10-15%). It seems that there is a distribution of cells within root tissue regarding their sensitivity to osmotic stress.

[Use of paramagnetic ions in the study of intercellular water transport by nuclear magnetic resonance with pulsed gradient ofthe magnetic field]. / Ispol'zovanie paramagnitnykh ionov v issledovaniiakh mezhkletochnogo transporta vody metodom IaMR s impul'snym gradientom magnitnogo polia.

A methodical approach to the studies of water transport in biological cells by NMR method with impulse gradient of the magnetic field is proposed. It allows to exclude experimentally water transport through the plasmalemma, without touching upon transport along intercellular contacts. The effect is achieved by preliminary introduction of paramagnetic ions into intercellular space.

[Probable penetration of paramagnetic ions into biological cells estimated by impulse NMR]. / Otsenka veroiatnosti proniknoveniia paramagnitnykh ionov v kletki impul'snym metodom IaMR.

Water exchange through biological cell membranes was studied by impulse NMR method with paramagnetic inclusions for estimating probability of penetration of paramagnetic ions inside the cells. It is suggested here to use the measurements of the time of lateral relaxation of intracellular water at impulse radiofrequency saturation of longitudinal magnetization.