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Related to Tonoplast: plasmodesmata


The membrane surrounding a plant-cell vacuole.
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 It might be outdated or ideologically biased.



the membrane that surrounds a cell vacuole, similar in structure to the membranes of the endoplasmic network. Tonoplasts have selective permeability and the capacity for active transport of ions.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Diber et al., "Improving plant stress tolerance and yield production: is the tonoplast aquaporin SlTIP2;2 a key to isohydric to anisohydric conversion?," New Phytologist, vol.
plasma membrane intrinsic proteins; qPCR, real-time polymerase chain reaction; TIPs, tonoplast intrinsic proteins; XIPs, X-intrinsic proteins.
Potential ESTs from the MIP gene superfamily were identified using the keywords "aquaporin," "major intrinsic protein," "PIP," "TIP," "PIN," "SIP" "plasma membrane intrinsic protein" "tonoplast intrinsic protein," "nodulin-26-like intrinsic protein" and "small basic intrinsic protein" in the EST annotations, or "water transporter" in the GO terms.
The presence of V-ATPases is not exclusively restricted to the tonoplast but they have also been detected in other subcellular fractions in the plant cell.
Activated SOS2 kinase regulates sodium efflux and sequestration of sodium into the vacuole by activating [Na.sup.+]/[H.sup.+] antiporters of plasma membrane and tonoplast, respectively.
Arabidopsis V-ATPase activity at the tonoplast is required for efcient nutrient storage but not for sodium accumulation.
The PIP2 protein, an aquaporin that specializes in osmotic fluid transport [47], functions as a water channel to transport water through the plasma membrane and tonoplast to adjust the osmotic pressure under stress conditions [48, 49], exhibiting an inducible expression pattern during drought stress and peaking at expression level in the early stress period (3 days after water withdrawal), indicating that the expression of this gene might play a critical role in early drought defense.
Effects of salinity on activities of [H.sup.+]-ATPase, [H.sup.+]-PPase and membrane lipid composition in plasma membrane and tonoplast vesicles from soybean (Glycine max L) seedlings.
Amongst other orthologs, mammalian AQP8- and the plant tonoplast intrinsic protein (TIP)-type channels, which have been termed aquaammoniaporins (Jahn et al., 2002), are not unique in transporting ammonia.
As (III) or complexed As (III) is then transported across the tonoplast and sequestered in the vacuole.
Ions are transported by [Na.sup.+]/[H.sup.+] antiport transporters on the tonoplast or in the plasmatic membrane (APSE; BLUMWALD, 2007).