Turgor


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turgor

[′tər·gər]
(botany)
Distension of a plant cell wall and membrane by the fluid contents.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Turgor

 

the state of tension of cell membranes that is caused by the osmotic pressure of the intracellular fluid (P int), the osmotic pressure of the external solution (P ext), and the resilience of the cell membrane. In animal cells, except for the cells of some Coelenterata, this resilience is generally minimal. Most animal cells lack turgor and maintain their integrity only in isotonic or near-isotonic solutions; in these cells the difference between the P int and the P ext is less than 0.5–1.0 atm.

In living plant cells, the P int is always greater than the P ext, but the cell membrane does not rupture owing to the presence of a cellulose cell wall. The difference between the P int and the P ext in such plants as halophytes and fungi reaches 50–100 atm, but even then the cell wall’s reserve of strength amounts to 60–70 percent. In most plants the relative elongation of the cell membrane that results from turgor does not exceed 5–10 percent, and the turgor pressure is in the range of 5–10 atm. Turgor gives plant tissues resilience and strength. All stages of autolysis, fading, and aging are accompanied by a decline in turgor.

V. V. KABANOV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Osmotic pressure is responsible for lysis in animal cells and turgor in plant cells, but the term, as it is applied to biological systems, refers to the pressure created by water molecules striking the interior surfaces of the plasma membranes.
The cucumber leaves in open condition would have faced water deficit causing a fall in turgor pressure and subsequent closure of stomata, thus, reducing the rate of carbon exchange drastically and thereby reducing the photosynthetic rate also.
c) Thirst, skin turgor and mucous membrane moisture
Conventional methods of processing cause cell damage and a significant loss of turgor while converting the vegetable from raw to cooked.
However, since we cannot demonstrate whether or not these eggs were fertilized, we classified all eggs without turgor, or without visible embryonic tissue, as "unfertilized."
Relative water content at zero turgor ([R.sup.0]) was similar in Tamarix and Salix and was significantly lower than that for Populus.
An analysis of variance of the PV curve data showed only a significant effect of date on saturation osmotic potential (F = 4.94, P [less than] 0.05) and no significant effect of species or species x date for either turgor loss point or osmotic potential at full saturation.
Height declines resulted from shrinkage of the above-ground plant parts, possibly because of loss of turgor. The control grew tallest with the one- and two-day inundation lengths slightly shorter.
Potassium (K) fertilization can be considered as an alternative, which can minimize the deleterious effects caused by the high concentrations of salts in the water, because this macronutrient plays a key role in the osmotic regulation and promotes turgor maintenance in guard cells, which results in absorption of water by these cells and by adjacent cells and, consequently, generates more turgor and stomatal opening (Langer et al., 2004).
The contribution of each ion to total osmotic potential at full turgor (Psp) was calculated as described by Ming et al.
The heritability for leaf carotenoids increased under water stress, contrary to it turgor potential decreased under stress regime.