Freezing and osmotic dehydration of winter rye cell protoplasts

Siminovitch, D.; Singh, Judith; Keller, W. A.; Roche, I.A. de la

doi:10.1016/0011-2240(76)90084-5

Cited by 5 publications

(3 citation statements)

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“…Increased cell wall thickness and mechanical strength during cold acclimation were also found in several other species (e.g., Rajashekar and Lafta 1996, Stefanowska et al 1999, Arias et al 2015. In contrast, cell walls were not shown to contribute to extracellular freezing tolerance of cell membranes in a few studies, which reported that isolated protoplasts (with no cell walls) had similar or higher freezing tolerances compared with intact cells ( Siminovitch et al 1976, Singh 1979, Tao et al 1983, Murai and Yoshida 1998. It is possible that cell walls in intact tissues do impose more mechanical pressure during extracellular freezing compared with the isolated protoplasts in solution, but mechanical pressure on cell membranes is unavoidable in intact plant tissues, and the rigid cell wall would transfer less mechanical pressure to the cell membrane and cause less membrane damage.…”

Section: The Role Of Cell Wall Elasticity In Leaf Freezing Resistancementioning

confidence: 80%

“…Cell walls contribute to the extracellular freezing tolerance of cell membranes, perhaps as barriers against the propagation of extracellular ice ( Wisniewski et al 1991, Smallwood and Bowles 2002, Yamada et al 2002, but some results are inconsistent with this conceptual model. Extracellular freezing tolerance in isolated suspended protoplast (with no cell wall) is similar to that in intact cells ( Siminovitch et al 1976, Singh 1979). Isolated suspended protoplasts may even have higher extracellular freezing tolerance than intact cells ( Tao et al 1983, Murai andYoshida 1998), suggesting negative effects of cell walls on extracellular freezing tolerance of the cell membrane.…”

Section: Introductionmentioning

confidence: 77%

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Freezing resistance in Patagonian woody shrubs: the role of cell wall elasticity and stem vessel size

et al. 2016

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Freezing resistance through avoidance or tolerance of extracellular ice nucleation is important for plant survival in habitats with frequent subzero temperatures. However, the role of cell walls in leaf freezing resistance and the coordination between leaf and stem physiological processes under subzero temperatures are not well understood. We studied leaf and stem responses to freezing temperatures, leaf and stem supercooling, leaf bulk elastic modulus and stem xylem vessel size of six Patagonian shrub species from two sites (plateau and low elevation sites) with different elevation and minimum temperatures. Ice seeding was initiated in the stem and quickly spread to leaves, but two species from the plateau site had barriers against rapid spread of ice. Shrubs with xylem vessels smaller in diameter had greater stem supercooling capacity, i.e., ice nucleated at lower subzero temperatures. Only one species with the lowest ice nucleation temperature among all species studied exhibited freezing avoidance by substantial supercooling, while the rest were able to tolerate extracellular freezing from -11.3 to -20 °C. Leaves of species with more rigid cell walls (higher bulk elastic modulus) could survive freezing to lower subzero temperatures, suggesting that rigid cell walls potentially reduce the degree of physical injury to cell membranes during the extracellular freezing and/or thaw processes. In conclusion, our results reveal the temporal-spatial ice spreading pattern (from stem to leaves) in Patagonian shrubs, and indicate the role of xylem vessel size in determining supercooling capacity and the role of cell wall elasticity in determining leaf tolerance of extracellular ice formation.

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Section: The Role Of Cell Wall Elasticity In Leaf Freezing Resistancementioning

confidence: 80%

Section: Introductionmentioning

confidence: 77%

Freezing resistance in Patagonian woody shrubs: the role of cell wall elasticity and stem vessel size

et al. 2016

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“…Free plant protoplasts afford a system for studying the cellular and biochemical properties of these membranes free of the complications associated with presence of cell walls (12,15). The preparation of protoplasts from tissues of both unhardened and hardened plants which retain the original properties of freezing resistance of their parent cells has therefore been a target for investigators in this field.…”

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confidence: 99%

Protoplasts Surviving Freezing to −196 C and Osmotic Dehydration in 5 Molar Salt Solutions Prepared from the Bark of Winter Black Locust Trees

Siminovitch¹

1979

Plant Physiol.

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Free protoplasts were prepared from the living bark tissue of the trunk of summer and winter black locust trees by enzymic digestion of thin slices of the tissue for 3 hours in a medium containing 2% Onozuka cellulase, 2% Rhozyme pectinase, and 2% Driselase in mannitol solutions using 0.4 molar mannitol for summer tissue and 1.0 molar mannitol for winter tissues.Cleaned suspensions of protoplasts and also thin slices of tissue with cells intact were frozen to temperatures of -10 C, -20 C, -30 C, -40 C and liquid nitrogen in sucrose and balanced salt solutions. Similar suspensions of protoplasts were also subjected to strong osmotic dehydration (plasmorrhysis) in a series of balanced salt solutions of increasing molarity. Tests for survival showed that protoplasts retain the same properties of either extreme susceptibility or extreme resistance to injury by freezing or osmotic dehydration as the cells from which they are prepared. Winter protoplasts showed capability for tolerating freezing to -196 C and plasmorrhysis in 5 molar salt solutions. These results indicate that protoplasts are a valid and useful system for investigating the properties of the protoplasm and surface membranes associated with the seasonal development of extreme hardiness in the cells of woody plants.Studies of freezing injury and resistance in plants increasingly point to the plasma membrane as the primary site of these phenomena (9)(10)(11)16). Free plant protoplasts afford a system for studying the cellular and biochemical properties of these membranes free of the complications associated with presence of cell walls (12, 15). The preparation of protoplasts from tissues of both unhardened and hardened plants which retain the original properties of freezing resistance of their parent cells has therefore been a target for investigators in this field. Such protoplast preparations have been made recently from moderately hardy winter cereals which are completely killed by freezing to -7 C in the unhardened condition and tolerant of -18 C in the hardened condition (1). These protoplasts have permitted studies that indicate the protoplasts not only behave like normal cells in freezing (13) but possess the same differences in degree of resistance to freezing and osmotic dehydration as their parent cells (7,14 membranes. The present paper describes the successful preparation of protoplasts from the bark of the winter and summer black locust trees which retain almost entirely the respective extremes of tolerance or susceptibility to freezing and osmotic dehydration of the cells and tissues from which they were prepared. MATERIALS AND METHODSThe living bark tissues were excised from the trunks of a group of 10-year-old black locust trees growing in the Ottawa area. Summer trees were sampled during the month of July, while winter tissues were obtained from thawed short lengths of trunk cut from the same group of trees in January and stored frozen at -10 C for 6 months. The cold hardiness of these frozen-stored logs was identical with that of...

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