The Relation of Cabbage Hardiness to Bound Water, Unfrozen Water, and Cell Contraction When Frozen

Levitt, J.

doi:10.1104/pp.14.1.93

Cited by 20 publications

(6 citation statements)

References 4 publications

(4 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After 35 days of hardening the LT5o for Kharkov is -19 C and the LT5o for Yorkstar is -13 C; the difference in Av2 for these two cultivars is only 0.7 Hz. During hardening of Manitou, Av½ increased 5 Hz and the LT50 increased 2 C. If the hardy cultivar Ulianovka was exposed to similar conditions AvY2 increased 8 Hz and the LT50 increased by 16 C. Although Av½2 is easier and faster to measure than LT50, it is still not preferable.…”

Section: Pulsed Nmr Of Wheat and Rye Crownsmentioning

confidence: 99%

“…The 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.…”

Section: Continuous Wave Nmr Measurementsmentioning

confidence: 99%

See 1 more Smart Citation

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

et al. 1979

View full text Add to dashboard Cite

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 ...

show abstract

Section: Pulsed Nmr Of Wheat and Rye Crownsmentioning

confidence: 99%

Section: Continuous Wave Nmr Measurementsmentioning

confidence: 99%

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

et al. 1979

View full text Add to dashboard Cite

show abstract

“…Alternatively, decreasing the osmotic potential of the cell, by osmotic adjustment, prior to freezing will reduce the extent of cellular dehydration at a given high subzero temperature (17,18). The reduction of cellular dehydration will be directly proportional to the decrease in osmotic potential.…”

mentioning

confidence: 99%

Freezing Tolerance of Citrus, Spinach, and Petunia Leaf Tissue

Yelenosky¹,

Guy²

1989

Plant Physiol.

View full text Add to dashboard Cite

Seasonal variations in freezing tolerance, water content, water and osmotic potential, and levels of soluble sugars of leaves of field-grown Valencia orange (Citrus sinensis) trees were studied to determine the ability of citrus trees to cold acclimate under natural conditions. Controlled environmental studies of young potted citrus trees, spinach (Spinacia pleracea), and petunia (Petunia hybrids) were carried out to study the water relations during cold acclimation under less variable conditions. During the coolest weeks of the winter, leaf water content and osmotic potential of field-grown trees decreased about 20 to 25%, while soluble sugars increased by 100%. At the same time, freezing tolerance increased from lethal temperature for 50% (LTso) of -2.8 to -3.80C. In contrast, citrus leaves cold acclimated at a constant 100C in growth chambers were freezing tolerant to about -60C. The calculated freezing induced cellular dehydration at the LT5o remained relatively constant for field-grown leaves throughout the year, but increased for leaves of plants cold acclimated at 100C in a controlled environment. Spinach leaves cold acclimated at 50C tolerated increased cellular dehydration compared to nonacclimated leaves. Cold acclimated petunia leaves increased in freezing tolerance by decreasing osmotic potential, but had no capacity to change cellular dehydration sensitivity. The result suggest that two cold acclimation mechanisms are involved in both citrus and spinach leaves and only one in petunia leaves. The common mechanism in all three species tested was a minor increase in tolerance (about -10C) resulting from low temperature induced osmotic adjustment, and the second in citrus and spinach was a noncolligative mechanism that increased the cellular resistance to freeze hydration.During extracellular freezing, ice first forms in the dilute apoplastic solution and a water potential gradient is established between the extracellular ice crystal and the intracellular liquid water. The lower water potential of ice as compared to that of liquid cellular water at the same temperature will cause liquid water to move from the cell to the extracellular ice (19). This process, depending on the temperature and concentration of the cell sap imposes a dehydration stress 'Part of this work was supported by a U.S. Department of Agriculture competitive research grant 85-CRCR-1-1649. University of Florida Agricultural Experiment Station Technical paper 8889. on the cell. When the cellular water potential of the partially dehydrated cell equals that of the extracellular ice, an equilibrium is established and further dehydration will not occur provided the temperature remains constant (15,23). If the temperature further declines or increases, water will flow out of or back into the cell. During such equilibrium freezing a tissue can behave either as an ideal solution or as a nonideal solution (15,23). In nonideal equilibrium freezing, negative wall pressure is believed to reduce the degree of cell dehydration and solute co...

show abstract

“…Levitt (9) in MATERIALS AND METHODS Seeds of three cultivars of wheat (Triticum aestivum L.), namely Manitou spring wheat, Cappelle-Desprez and Kharkov winter wheat, and Frontier fall rye (Secale cereale L.) were germinated at 15 C in a soil-sand-peat mixture (2:1:1). At the three leaf stage, plants were cold acclimated by the following temperature (light-period temperature/dark-period temperature) and photoperiod regimes: 10/8 C, 16 hr for the first 7 days, 8/5 C, 16 hr for the next 7 days, 5/3 C, 14 hr for the next 7 days, and 5/1 to 0 C, 12 hr for the following 21 days.…”

mentioning

confidence: 99%

Determination of Unfrozen Water in Winter Cereals at Subfreezing Temperatures

1975

View full text Add to dashboard Cite

The freezing of water in acclimated and nonacclimated cereals was studied using pulsed nuclear magnetic resonance spectroscopy. The quantity of unfreezable water per unit dry matter was not strongly dependent on the degree of cold acclimation. In contrast, the fraction of water frozen which was tolerated by nonacclimated winter cereals and by an acclimated spring wheat (Triticum aestivum L.) was less than in acclimated hardy cereals. The freezing curves had the following form: LT = LoATm/T + K LT and Lo are liquid water per unit dry matter at T and 0 C, respectively. ATm is the melting point depression and K is the liquid water which does not freeze.Horticultural Science, University of Mininesota, St. Paul, 1939 used the cryoscopic and plasmolytic methods to determine the freezing point lowerings of the cell sap, then assumed ideal freezing behavior. Ideal freezing behavior described here implies the absence of eutectics, the formation of pure ice during freezing, and the concentration of ideal solute in the liquid phase. Then the freezing curve predicted by plotting the liquid water against temperature is a hyperbola. Johansson (4) made extensive use of calorimetric methods to study the freezing process. He also assumed the hyperbolic form for the freezing curve and restricted his measurements of liquid water to two temperatures, -2.65 and -9C.Nuclear magnetic resonance has frequently been used to determine the liquid water content of partially frozen samples (1, 2, 6-8, 11). In this study, pulsed NMR' spectroscopy is used to study the freezing process in crown tissue from a spring wheat, two winter wheats, and a hardy fall rye. The relationship of the freezing process to the killing temperature and the mathematical form of the freezing curve are described. Determinations of ice formation in the plant generally involve cryoscopic, plasmolytic, or calorimetric methods. Levitt (9) in MATERIALS AND METHODS Seeds of three cultivars of wheat (Triticum aestivum L.), namely Manitou spring wheat, Cappelle-Desprez and Kharkov winter wheat, and Frontier fall rye (Secale cereale L.) were germinated at 15 C in a soil-sand-peat mixture (2:1:1). At the three leaf stage, plants were cold acclimated by the following temperature (light-period temperature/dark-period temperature) and photoperiod regimes: 10/8 C, 16 hr for the first 7 days, 8/5 C, 16 hr for the next 7 days, 5/3 C, 14 hr for the next 7 days, and 5/1 to 0 C, 12 hr for the following 21 days. The last 7 days of hardening included a frost of -2 to -3 C for 4 hr during the dark period. This cold hardening regime acclimates crowns of Manitou to -5.5 + 0.5 C, Cappelle-Desprez to -11 1 C, Kharkov to -18 ± 1 C, and Frontier to -24 t 1 C. Hardiness was determined by slowly cooling crowns at -2 C/hr. Ten crowns were used per test temperature spaced at 2 C intervals. After 3 weeks of 20 C, 24-hr photoperiod the crowns were rated for viability by regrowth of roots and leaves. One series of Kharkov plants was hardened for 14 days as described above for the first 14 d...

show abstract

The Relation of Cabbage Hardiness to Bound Water, Unfrozen Water, and Cell Contraction When Frozen

Cited by 20 publications

References 4 publications

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

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

Freezing Tolerance of Citrus, Spinach, and Petunia Leaf Tissue

Determination of Unfrozen Water in Winter Cereals at Subfreezing Temperatures

Contact Info

Product

Resources

About