Abstract
We identified three genes homologous to water channels in the plasma membrane type subfamily from roots of barley seedlings. These genes were designated HvPIP2;1, HvPIP1;3, and HvPIP1;5 after comparison to Arabidopsis aquaporins. Competitive reverse transcription (RT)-PCR was applied in order to distinguish and to quantify their transcripts. The HvPIP2;1 transcript was the most abundant among the three in roots. Salt stress (200 mM NaCl) down-regulated HvPIP2;1 (transcript and protein), but had almost no effect on the expressions of HvPIP1;3, or HvPIP1;5. Approximately equal amounts of the transcripts of the three were detected in shoots, and salt stress enhanced the expression of HvPIP2;1 but not of HvPIP1;3, or HvPIP1;5. HvPIP2;1 protein was confirmed to be localized in the plasma membrane. Functional expression of HvPIP2;1 in Xenopus oocytes confirmed that HvPIP2;1 encoded an aquaporin that transports water. This water permeability was reduced by HgCl(2), which is a typical water channel inhibitor. This activity was not modified by some inhibitors against protein kinase and protein phosphatase.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptation, Physiological / genetics
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Adaptation, Physiological / physiology
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Algorithms
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Amino Acid Sequence
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Animals
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Aquaporins / antagonists & inhibitors
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Aquaporins / genetics*
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Aquaporins / physiology
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Arabidopsis Proteins*
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Carbazoles / pharmacology
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Cell Membrane / metabolism
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Cell Membrane Permeability / drug effects
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DNA, Complementary / genetics
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DNA, Complementary / metabolism
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Female
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Gene Expression Regulation, Plant
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Hordeum / drug effects
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Hordeum / genetics*
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Hordeum / physiology
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Indole Alkaloids
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Ion Channels / genetics
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Mercuric Chloride / pharmacology
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Molecular Sequence Data
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Okadaic Acid / pharmacology
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Oocytes / physiology
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Osmotic Pressure / drug effects
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Phosphoprotein Phosphatases / antagonists & inhibitors
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Phosphorylation
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Phylogeny
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Plant Proteins / genetics
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Plant Proteins / metabolism
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Plant Roots / drug effects
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Plant Roots / genetics*
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Plant Roots / physiology
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Protein Kinase Inhibitors
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Sequence Homology, Amino Acid
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Sodium Chloride / pharmacology
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Water / pharmacology
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Water / physiology
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Xenopus laevis
Substances
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Aquaporins
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Arabidopsis Proteins
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Carbazoles
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DNA, Complementary
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Indole Alkaloids
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Ion Channels
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Plant Proteins
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Protein Kinase Inhibitors
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major intrinsic protein, plant
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plasma membrane intrinsic protein 2 Arabidopsis
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Water
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Okadaic Acid
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Sodium Chloride
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Mercuric Chloride
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staurosporine aglycone
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Phosphoprotein Phosphatases
Associated data
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GENBANK/AB009307
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GENBANK/AB009308
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GENBANK/AB009309