Turgor pressure changes trigger characteristic changes in the electrical conductance of the tonoplast and the plasmalemma of the marine alga Valonia utricularis

A method is described for the simultaneous determination of rapid changes of the cell turgor pressure (hydrostatic pressure) in algal cells (cell size must be at least 3 mm in diameter), and of the net volume flow across the cell membrane arising after a change of the cell turgor pressure or of the osmotic pressure in the outside medium. On the basis of the equations of irreversible thermodynamics it is possible to calculate the hydraulic conductivity of the cell membrane from these measurements, as it is theoretically shown.The hydraulic conductivities of the marine alga Valonia utricularis determined in two independent ways (by osmotic and hydrostatic experiments) are equal. For exosmosis, Lpex (hydrostatic) and Lpex (osmotic) amounted to (9,6 ± 1,0) ·10-7 and (9,8 ± 1,9) · 10-7 respectively cm · sec-1 · atm-1, and for endomosis, Lpen (hydrostatic) was (9,4 ± 1,1) ·10-7 cm · sec-1 · atm-1.A polarity in the water movement across the cell membranes as discussed in the literature could not be found for Valonia utricularis.

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Elucidation of the Mechanisms Underlying Hypo-osmotically Induced Turgor Pressure Regulation in the Marine Alga Valonia utricularis

The Journal of Membrane Biology ◽

10.1007/s00232-006-0047-9 ◽

2006 ◽

Vol 213 (1) ◽

pp. 47-63 ◽

Cited By ~ 1

Author(s):

Karl-Andree Binder ◽

Frank Heisler ◽

Markus Westhoff ◽

Lars H. Wegner ◽

Ulrich Zimmermann

Keyword(s):

Marine Alga ◽

Turgor Pressure ◽

Pressure Regulation ◽

Valonia Utricularis ◽

Turgor Pressure Regulation

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Structural Peculiarities Dominate the Turgor Pressure Response of the Marine Alga Valonia utricularis upon Osmotic Challenges

The Journal of Membrane Biology ◽

10.1007/s00232-002-1068-7 ◽

2003 ◽

Vol 192 (2) ◽

pp. 123-139 ◽

Cited By ~ 11

Author(s):

U. Zimmermann ◽

M. Heidecker ◽

S. Mimietz ◽

L. H. Wegner

Keyword(s):

Marine Alga ◽

Turgor Pressure ◽

Pressure Response ◽

Structural Peculiarities ◽

Valonia Utricularis

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Turgor Pressure Regulation in Valonia utricularis

PLANT PHYSIOLOGY ◽

10.1104/pp.58.5.608 ◽

1976 ◽

Vol 58 (5) ◽

pp. 608-613 ◽

Cited By ~ 43

Author(s):

Ulrich Zimmermann ◽

Ernst Steudle ◽

Peter I. Lelkes

Keyword(s):

Turgor Pressure ◽

Pressure Regulation ◽

Valonia Utricularis ◽

Turgor Pressure Regulation

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Osmotic Adaption in the Marine Alga Griffithsia monilis (Rhodophyceae): The Role of Ions and Organic Compounds

Functional Plant Biology ◽

10.1071/pp9790523 ◽

1979 ◽

Vol 6 (4) ◽

pp. 523 ◽

Cited By ~ 1

Author(s):

M.A Bisson ◽

G.O Kirst

Keyword(s):

Steady State ◽

Osmotic Pressure ◽

Marine Alga ◽

Turgor Pressure ◽

Red Alga ◽

Steady State Concentration ◽

Photosynthetic Product ◽

The Individual ◽

State Concentration

The red alga G. monilis maintains its turgor pressure constant at 4.05 � 0.14 x 10*5 Pa (179 measurements), or 166 mosmol/kg, over a range of external osmotic pressures from 900 to 1300 mosmol/kg. It is capable of regulating turgor pressure in the dark or when sorbitol is used to increase the external osmotic pressure. Complete regulation of turgor requires 24-36 h, although much of the regulation is accomplished in the first 2 h. The change in II*i is achieved by controlling the concentrations of K+, Na+, and Cl-. In the vacuole, KCl concentration is higher than NaCl, and KCI is usually more important than NaCl in regulating turgor, although the importance of the individual cations varies with specific conditions. The steady-state concentration of the principal photosynthetic product, digeneaside, increases with increasing external osmotic pressure. Its concentration is too low to affect the internal osmotic pressure if it is distributed evenly throughout the cell but, if it is restricted to the cytoplasm, it can play a major role in regulating the volume of the cytoplasm.

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