Water Mobility and Microstructure Evolution in the Germinating Medicago truncatula Seed Studied by NMR Relaxometry. A Revisited Interpretation of Multicomponent Relaxation

Abstract

The water status of Medicago truncatula Gaertn. seed was followed by low-field NMR relaxometry during germination with and without oryzalin or fusicoccin used as growth modulators. T1 and T2 relaxation times and proportions P1 and P2 were determined on fresh, frozen, and freeze-thawed samples to characterize changes in water dynamics and compartmentation and in the nonfreezing water fraction. The results demonstrate that low-field NMR relaxometry allowed differentiating germination phases and events occurring during them as well as perturbations related to the presence of growth modulators. The results provide clear evidence that the classical multicomponent relaxation interpretation cannot directly relate T2 components and morphological compartments in biological tissue.

Activity of Isoliensinine in Improving the Symptoms of Type 2 Diabetic Mice via Activation of AMP-Activated Kinase and Regulation of PPARγ

“…Natural products are gaining an increasing amount of attention from pharmaceutical researchers and clinicians because of their efficiency, safety, and immediate availability. , Over the past 30 years, more than 70% of drugs approved by the U.S. Food and Drug Administration originated from natural products . To look for potential hypoglycemic agents from natural products, a cell-based GLUT4 translocation assay system using stable L6 myotubes expressing pIRAP-mOrange cDNAs was established to screen potential antidiabetic plants extracts, fractions, and individual natural compounds by evaluating their effects on GLUT4 translocation. , During the screening of a plant extract library (800 biotas) on GLUT4 translocation, we found that the total alkaloids from embryos of Nelumbo nucifera displayed a promising positive activity on GLUT4 translocation.…”

Benchmarking of techniques used to assess the freeze damage in potatoes

“…It was observed that " % component values (relaxation time and proton population) for IF and FF conditions were not significantly different (p > 0.05) between each other, meanwhile, these values were significantly different (p < 0.05) with that obtained for SF condition. The lowest value of " % time observed for slow freezing (0.72 ms instead of around 0.80 ms for the other freezing conditions) can be explained by a greater destruction followed by a diffusion of "solutes" inducing a relative increase in viscosity(Lahaye, Falourd, Limami, & Foucat, 2015). The " & component relaxation times for all freezing conditions were not different from each other.…”

“…For all freezing conditions, the mobility of water associated with non-starch vacuoles, nuclei and cytoplasm (" + and " , ) decreased. This reflects a reorganization of the fluids following a partial rupture of the cellular structures (Lahaye et al, 2015) irrespective of the freezing speed. Compared to fresh sample, the decrease in " , time was lower for FF process (≈ 46%) and was followed by SF (≈ 53%) and IF (≈ 54%) process.…”

Enzymatic Degradation of Maize Shoots: Monitoring of Chemical and Physical Changes Reveals Different Saccharification Behaviors

“…As illustrated in Figure 7, the analysis of relaxation curves led to pro les with multiple distinct peaks. Because no simple direct relationship exists between components and the morphological compartments in biological tissues [58], each peak can be preferentially assigned to a pool of water at a given range of mobility corresponding to speci c molecular environment/interactions. Both the number of components, the relative surface area, and the individual mean relaxation time values associated with these peaks changed with increasing water concentration and differed between the ve fractions Mc, Mm-, Mm+, Mf-and Mf+.…”