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EMBO J
2003 May 01;229:2004-14. doi: 10.1093/emboj/cdg207.
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Functional analysis of AtHKT1 in Arabidopsis shows that Na(+) recirculation by the phloem is crucial for salt tolerance.
Berthomieu P
,
Conéjéro G
,
Nublat A
,
Brackenbury WJ
,
Lambert C
,
Savio C
,
Uozumi N
,
Oiki S
,
Yamada K
,
Cellier F
,
Gosti F
,
Simonneau T
,
Essah PA
,
Tester M
,
Véry AA
,
Sentenac H
,
Casse F
.
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Two allelic recessive mutations of Arabidopsis, sas2-1 and sas2-2, were identified as inducing sodium overaccumulation in shoots. The sas2 locus was found (by positional cloning) to correspond to the AtHKT1 gene. Expression in Xenopus oocytes revealed that the sas2-1 mutation did not affect the ionic selectivity of the transporter but strongly reduced the macro scopic (whole oocyte current) transport activity. In Arabidopsis, expression of AtHKT1 was shown to be restricted to the phloem tissues in all organs. The sas2-1 mutation strongly decreased Na(+) concentration in the phloem sap. It led to Na(+) overaccumulation in every aerial organ (except the stem), but to Na(+) underaccumulation in roots. The sas2 plants displayed increased sensitivity to NaCl, with reduced growth and even death under moderate salinity. The whole set of data indicates that AtHKT1 is involved in Na(+) recirculation from shoots to roots, probably by mediating Na(+) loading into the phloem sap in shoots and unloading in roots, this recirculation removing large amounts of Na(+) from the shoot and playing a crucial role in plant tolerance to salt.
Apse,
Salt tolerance conferred by overexpression of a vacuolar Na+/H+ antiport in Arabidopsis.
1999, Pubmed
Apse,
Salt tolerance conferred by overexpression of a vacuolar Na+/H+ antiport in Arabidopsis.
1999,
Pubmed
Becker,
Binary vectors which allow the exchange of plant selectable markers and reporter genes.
1990,
Pubmed
Clough,
Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana.
1998,
Pubmed
Davenport,
A weakly voltage-dependent, nonselective cation channel mediates toxic sodium influx in wheat.
2000,
Pubmed
Deeken,
Loss of the AKT2/3 potassium channel affects sugar loading into the phloem of Arabidopsis.
2002,
Pubmed
,
Xenbase
Demidchik,
Sodium fluxes through nonselective cation channels in the plasma membrane of protoplasts from Arabidopsis roots.
2002,
Pubmed
Diatloff,
Site directed mutagenesis reduces the Na+ affinity of HKT1, an Na+ energized high affinity K+ transporter.
1998,
Pubmed
Durell,
Structural models of the KtrB, TrkH, and Trk1,2 symporters based on the structure of the KcsA K(+) channel.
1999,
Pubmed
Horie,
Two types of HKT transporters with different properties of Na+ and K+ transport in Oryza sativa.
2001,
Pubmed
,
Xenbase
Kato,
Evidence in support of a four transmembrane-pore-transmembrane topology model for the Arabidopsis thaliana Na+/K+ translocating AtHKT1 protein, a member of the superfamily of K+ transporters.
2001,
Pubmed
,
Xenbase
King,
Enhancement of Phloem exudation from cut petioles by chelating agents.
1974,
Pubmed
Lacombe,
A shaker-like K(+) channel with weak rectification is expressed in both source and sink phloem tissues of Arabidopsis.
2000,
Pubmed
,
Xenbase
Lagarde,
Tissue-specific expression of Arabidopsis AKT1 gene is consistent with a role in K+ nutrition.
1996,
Pubmed
Laurie,
A role for HKT1 in sodium uptake by wheat roots.
2002,
Pubmed
Lazo,
A DNA transformation-competent Arabidopsis genomic library in Agrobacterium.
1991,
Pubmed
Liu,
Partial deletion of a loop region in the high affinity K+ transporter HKT1 changes ionic permeability leading to increased salt tolerance.
2000,
Pubmed
,
Xenbase
Lohaus,
Solute balance of a maize (Zea mays L.) source leaf as affected by salt treatment with special emphasis on phloem retranslocation and ion leaching.
2000,
Pubmed
Munns,
Comparative physiology of salt and water stress.
2002,
Pubmed
Mäser,
Altered shoot/root Na+ distribution and bifurcating salt sensitivity in Arabidopsis by genetic disruption of the Na+ transporter AtHKT1.
2002,
Pubmed
Mäser,
Glycine residues in potassium channel-like selectivity filters determine potassium selectivity in four-loop-per-subunit HKT transporters from plants.
2002,
Pubmed
,
Xenbase
Nublat,
sas1, an Arabidopsis mutant overaccumulating sodium in the shoot, shows deficiency in the control of the root radial transport of sodium.
2001,
Pubmed
Rubio,
Genetic selection of mutations in the high affinity K+ transporter HKT1 that define functions of a loop site for reduced Na+ permeability and increased Na+ tolerance.
1999,
Pubmed
,
Xenbase
Rubio,
Sodium-driven potassium uptake by the plant potassium transporter HKT1 and mutations conferring salt tolerance.
1995,
Pubmed
,
Xenbase
Rus,
AtHKT1 is a salt tolerance determinant that controls Na(+) entry into plant roots.
2001,
Pubmed
Schachtman,
Structure and transport mechanism of a high-affinity potassium uptake transporter from higher plants.
1994,
Pubmed
,
Xenbase
Shi,
The putative plasma membrane Na(+)/H(+) antiporter SOS1 controls long-distance Na(+) transport in plants.
2002,
Pubmed
Truernit,
The promoter of the Arabidopsis thaliana SUC2 sucrose-H+ symporter gene directs expression of beta-glucuronidase to the phloem: evidence for phloem loading and unloading by SUC2.
1995,
Pubmed
Uozumi,
The Arabidopsis HKT1 gene homolog mediates inward Na(+) currents in xenopus laevis oocytes and Na(+) uptake in Saccharomyces cerevisiae.
2000,
Pubmed
,
Xenbase
Véry,
Expression of a cloned plant K+ channel in Xenopus oocytes: analysis of macroscopic currents.
1995,
Pubmed
,
Xenbase
Zhang,
Transgenic salt-tolerant tomato plants accumulate salt in foliage but not in fruit.
2001,
Pubmed
Zhu,
Salt and drought stress signal transduction in plants.
2002,
Pubmed
