Permeability of the Plant Cell

Stadelmann, E.

doi:10.1146/annurev.pp.20.060169.003101

Cited by 32 publications

(16 citation statements)

References 23 publications

(26 reference statements)

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“…Transport assays in Chara australis showed that urea uptake is driven by an active, energy-dependent pathway, whereas at higher external concentrations, urea uptake followed a linear concentration dependency, indicating a second passive or diffusion-controlled transport pathway . This kinetic behavior is in agreement with early investigations on urea transport in other plant and animal systems, where urea transport was best described by facilitated diffusion and was found to be inhibited by mercury, phloretin, or urea analogs (Dainty and Ginzburg, 1964;Stadelman, 1969;Macey, 1984).…”

supporting

confidence: 90%

Urea Transport by Nitrogen-Regulated Tonoplast Intrinsic Proteins in Arabidopsis

Liu

Ludewig²,

Gassert³

et al. 2003

Plant Physiology

234

215

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Urea is the major nitrogen (N) form supplied as fertilizer in agricultural plant production and also an important N metabolite in plants. Because urea transport in plants is not well understood, the aim of the present study was to isolate urea transporter genes from the model plant Arabidopsis. Using heterologous complementation of a urea uptake-defective yeast (Saccharomyces cerevisiae) mutant allowed to isolate AtTIP1;1, AtTIP1;2, AtTIP2;1, and AtTIP4;1 from a cDNA library of Arabidopsis. These cDNAs encode channel-like tonoplast intrinsic proteins (TIPs) that belong to the superfamily of major intrinsic proteins (or aquaporins). All four genes conferred growth of a urea uptake-defective yeast mutant on 2 mm urea in a phloretin-sensitive and pH-independent manner. Uptake studies using 14C-labeled urea into AtTIP2;1-expressing Xenopus laevis oocytes demonstrated that AtTIP2;1 facilitated urea transport also in a pH-independent manner and with linear concentration dependency. Expression studies showed that AtTIP1;2, AtTIP2;1, and AtTIP4;1 genes were up-regulated during early germination and under N deficiency in roots but constitutively expressed in shoots. Subcellular localization of green fluorescent protein-fused AtTIPs indicated that AtTIP1;2, AtTIP2;1, and AtTIP4;1 were targeted mainly to the tonoplast and other endomembranes. Thus, in addition to their role as water channels, TIP transporters may play a role in equilibrating urea concentrations between different cellular compartments.

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supporting

confidence: 90%

Urea Transport by Nitrogen-Regulated Tonoplast Intrinsic Proteins in Arabidopsis

Liu

Ludewig²,

Gassert³

et al. 2003

Plant Physiology

234

215

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“…The range of atom % 15N was greater than could be expected from diffusion of the isotope into the tissue, despite the rapid rate of ammonia diffusion through plant membranes (Osterhout 1935(Osterhout , 1936Stadelmann 1969;Barr et al 1974;Walker 1980). The atom % 15N of rhizoid tissue, assuming diffusion of the available isotope, would be:…”

mentioning

confidence: 99%

Uptake of sediment ammonium and translocation in a marine green macroalga Caulerpa cupressoides1

Williams

1984

Limnology & Oceanography

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“…Stout et al [l I] measured water proton relaxation rates in Chloreiia cells suspended in media containing Mn'+; they found a mean residence time of 25 ms for water molecules inside the cells and a diffuSiOnal Water permeability Coefficient (Pd) Of 2.1 x 10m3 cm/s for the cell walls. Pd values for other plant membranes [5,8,9,12] are in the range from about 1 x 10m4 to 5 x lo-' cm/s. Water exchange through the thylakoid membrane inside chloroplasts is fast; Wydrzynsky et al [13], using isolated, broken chloroplasts, measured exchange lifetimes of less than 20 ms.…”

Section: Introductionmentioning

confidence: 96%

Water permeability of chloroplast envelope membranes

McCain

Markley

1985

FEBS Letters

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In tulip tree (Liriodendron tufipifera) leaves, the proton NMR signal from chloroplast water is resolved from that of water in other leaf compartments. We used the saturation-transfer NMR method to measure the mean water molecule residence time within a chloroplast, (88 f 17) ms at 20°C. From the measured chloroplast dimensions, we calculate an effective permeability coefficient of (9 + 2) x 10-4cm/s for the chloroplast envelope membrane. This is the first in vivo measurement of chloroplast water permeability. ChloroplastWater exchange Membrane permeability Water compartment

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Permeability of the Plant Cell

Cited by 32 publications

References 23 publications

Urea Transport by Nitrogen-Regulated Tonoplast Intrinsic Proteins in Arabidopsis

Urea Transport by Nitrogen-Regulated Tonoplast Intrinsic Proteins in Arabidopsis

Uptake of sediment ammonium and translocation in a marine green macroalga Caulerpa cupressoides1

Water permeability of chloroplast envelope membranes

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