Nuclear Magnetic Resonance Relaxation Times and Plasmalemma Water Exchange in Ivy Bark

Stout, Darryl G.; Steponkus, Peter L.; Cotts, R. M.

doi:10.1104/pp.62.4.636

Cited by 49 publications

(25 citation statements)

References 19 publications

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“…A good fit to the data could be made by assuming that the signal arose from two populations of water, each with a different magnetic environment producing two different relaxation times. Both Burke et al (2) and Stout et al (27) found, as in this study, that at least two populations of water with different relaxation times exist in plant tissue. These two populations of water do not rapidly exchange with each other as evidenced by the difference in relaxation rates.…”

Section: Pulsed Nmr Of Wheat and Rye Crownsmentioning

confidence: 64%

A Nuclear Magnetic Resonance Study of Water in Cold-acclimating Cereals

et al. 1979

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Continuous wave nuclear magnetic resonance (NMR) studies indicated that the line width of the water absorption peak (AP%) from crowns of winter and spring wheat (Titicum aestivum L.) increased during cold acclimation. There was a negative correlation between Air and crown water content, and both of these parameters were correlated with the lowest survival temperature at which 50% or more of the crowns were not killed by freezing (LT5o). Regression analyses indicated that APS and water content account for similar variability in LT5w Slow dehydration of unacclimated winter wheat crowns by artificial means resulted in similarly correlated changes in water content and A4Y. Rapid dehydration of unacclimated crowns reduced water content but did not influence AP%. The incubation of unacclimated winter wheat crowns in a sucrose medium reduced water content and increased Au's. The increase in AP% appears to be dependent in part on a reduction in water content and an increase in solutes.Longitudinal (TO) and transverse (T2) relaxation times of water protons in cereals at different stages of cold acclimation were measured using pulse NMR methods. The T, and T2 signals each demonstrated the existence of two populations of water, one with a short and one with a long relaxation time. During the first 3 weeks of acclimation, the long T2 decreased significantly in winter-hardy cereals, and did not change in a spring wheat until the 5th week of hardening. There was no change in the long T, until the 3rd week of hardening for the winter cereals and until the 7th week of hardening for the spring wheat. No simple relationship could be established between T, or T2 and cold hardiness. Neither continuous wave or pulsed NMR spectroscopy can be used as a diagnostic tool in predicting the cold hardiness of winter wheats. An increase in AvA or a reduction in relaxation times does not provide evidence for ordering of the bulk of the cell water.water content and an increase in hydrophilic compounds such as sugars (17), proteins (24), and nucleic acids (23). These hydrophilic compounds could affect the physical state of water which in turn would affect the amount of water which crystallizes at any given subzero temperature.Continuous wave NMR studies on animal tissue have shown that line width (Av½, one-half maximum amplitude of the water absorption peak) is significantly broader than in pure water (6,15). This has led to the suggestion that cellular water consists of several populations, including a "bound" or unfreezable fraction (1,5,6 MATERIALS AND METHODS CONTINUOUS WAVE NMR MEASUREMENTSThe physical state of water in plant cells has long been a subject of interest in relation to cold hardiness (16,17,22). NMR3 provides one method of studying water and water interactions in intact biological systems (1,2,6,11,18,19 Samples for analysis were stripped to two leaves and 3-cm sections were cut from just above the base. Studies of the effect of sample shape and spinning rate on line width showed that crooked samples had a line width ...

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Section: Pulsed Nmr Of Wheat and Rye Crownsmentioning

confidence: 64%

A Nuclear Magnetic Resonance Study of Water in Cold-acclimating Cereals

et al. 1979

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“…In ivy bark tissues (Stout et al, 1978) and in wilting leaves (Colire et al, 1988), extracellular and intracellular water have been associated with long and short T 2 , respectively. Water bound in chloroplasts and vacuoles of plant cells shows even longer T 2 values (Snaar and Van As, 1992;Sainis and Srinivasan, 1993).…”

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confidence: 99%

In Situ Investigation of Leaf Water Status by Portable Unilateral Nuclear Magnetic Resonance

et al. 2009

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A portable unilateral nuclear magnetic resonance (NMR) instrument was used to detect in field conditions the water status of leaves of herbaceous crops (Zea mays, Phaseolus vulgaris), mesophyllous trees (Populus nigra), and natural Mediterranean vegetation characterized by water-spending shrubs (Cistus incanus) and water-saving sclerophyllous trees (Quercus ilex). A good relationship was observed between NMR signal, leaf relative water content, and leaf transpiration in herbaceous leaves undergoing fast dehydration or slowly developing a drought stress. A relationship was also observed between NMR signal and water potential of Populus leaves during the development of a water stress and when leaves recovered from the stress. In the natural vegetation, the relationship between NMR signal and water status was found in Cistus, the species characterized by high transpiration rates, when measured during a drought stress period and after a rainfall. In the case of the sclerophyllous Quercus, the NMR signal, the relative water content, and the transpiration rate did not change at different leaf water status, possibly because a large amount of water is compartmentalized in cellular structures and macromolecules. The good association between NMR signal and relative water content was lost in leaves exposed for 24 h to dehydration or to an osmotic stress caused by polyethylene glycol feeding. At this time, the transverse relaxation time became longer than in leaves maintained under optimal water conditions, and two indicators of membrane damage, the ion leakage and the emission of products of membrane lipoxygenation [(Z)-3-hexenal, (Z)-3-hexenol, and (E)-2-hexenol], increased. These results taken all together give information on the physiological state of a leaf under a developing stress and show the usefulness of the NMR instrumentation for screening vegetation health and fitness in natural and cultivated conditions. It is concluded that the portable unilateral NMR instrument may be usefully employed in field conditions to monitor nondestructively the water status of plants and to assist agricultural practices, such as irrigation scheduling, to minimize stomatal closure and the consequent limitation to plant production.

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“…Stout et al [l I] measured water proton relaxation rates in Chloreiia cells suspended in media containing Mn'+; they found a mean residence time of 25 ms for water molecules inside the cells and a diffuSiOnal Water permeability Coefficient (Pd) Of 2.1 x 10m3 cm/s for the cell walls. Pd values for other plant membranes [5,8,9,12] are in the range from about 1 x 10m4 to 5 x lo-' cm/s. Water exchange through the thylakoid membrane inside chloroplasts is fast; Wydrzynsky et al [13], using isolated, broken chloroplasts, measured exchange lifetimes of less than 20 ms.…”

Section: Introductionmentioning

confidence: 97%

“…Water is generally present in plant tissue in two or more compartments that are isolated (on an NMR time scale) by slow exchange rates. The compartments in bark and stems have been identified [7,8] as extracellular and intracellular water. Different relaxation times from vacuolar and cytoplasmic water can be distinguished in maize roots [5].…”

Section: Introductionmentioning

confidence: 99%

“…Proton spin relaxation has been used to detect water compartments in wheat leaves [3] and * To whom correspondence should be addressed crowns [4], maize roots [S] and leaves [6], dogwood stems [7], ivy bark [8], Elodea [9], and Nitella [lo]. Water is generally present in plant tissue in two or more compartments that are isolated (on an NMR time scale) by slow exchange rates.…”

Section: Introductionmentioning

confidence: 99%

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Water permeability of chloroplast envelope membranes

McCain

Markley

1985

FEBS Letters

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In tulip tree (Liriodendron tufipifera) leaves, the proton NMR signal from chloroplast water is resolved from that of water in other leaf compartments. We used the saturation-transfer NMR method to measure the mean water molecule residence time within a chloroplast, (88 f 17) ms at 20°C. From the measured chloroplast dimensions, we calculate an effective permeability coefficient of (9 + 2) x 10-4cm/s for the chloroplast envelope membrane. This is the first in vivo measurement of chloroplast water permeability. ChloroplastWater exchange Membrane permeability Water compartment

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Nuclear Magnetic Resonance Relaxation Times and Plasmalemma Water Exchange in Ivy Bark

Cited by 49 publications

References 19 publications

A Nuclear Magnetic Resonance Study of Water in Cold-acclimating Cereals

A Nuclear Magnetic Resonance Study of Water in Cold-acclimating Cereals

In Situ Investigation of Leaf Water Status by Portable Unilateral Nuclear Magnetic Resonance

Water permeability of chloroplast envelope membranes

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