Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
J Exp Bot
2016 Aug 01;6715:4495-505. doi: 10.1093/jxb/erw237.
Show Gene links
Show Anatomy links
SLAH1, a homologue of the slow type anion channel SLAC1, modulates shoot Cl- accumulation and salt tolerance in Arabidopsis thaliana.
Qiu J
,
Henderson SW
,
Tester M
,
Roy SJ
,
Gilliham M
.
???displayArticle.abstract???
Salinity tolerance is correlated with shoot chloride (Cl(-)) exclusion in multiple crops, but the molecular mechanisms of long-distance Cl(-) transport are poorly defined. Here, we characterize the in planta role of AtSLAH1 (a homologue of the slow type anion channel-associated 1 (SLAC1)). This protein, localized to the plasma membrane of root stelar cells, has its expression reduced by salt or ABA, which are key predictions for a protein involved with loading Cl(-) into the root xylem. Artificial microRNA knockdown mutants of AtSLAH1 had significantly reduced shoot Cl(-) accumulation when grown under low Cl(-), whereas shoot Cl(-) increased and the shoot nitrate/chloride ratio decreased following AtSLAH1 constitutive or stelar-specific overexpression when grown in high Cl(-) In both sets of overexpression lines a significant reduction in shoot biomass over the null segregants was observed under high Cl(-) supply, but not low Cl(-) supply. Further in planta data showed AtSLAH3 overexpression increased the shoot nitrate/chloride ratio, consistent with AtSLAH3 favouring nitrate transport. Heterologous expression of AtSLAH1 in Xenopus laevis oocytes led to no detectible transport, suggesting the need for post-translational modifications for AtSLAH1 to be active. Our in planta data are consistent with AtSLAH1 having a role in controlling root-to-shoot Cl(-) transport.
Fig. 1. Expression level of AtSLAH1 (A) and AtSLAH3 (B) treated with control (2mM NaCl), 50mM and 100mM NaCl for 7 days, or 20 μM ± cis-trans-ABA for 4 or 16h. Arabidopsis (Col-0) were grown in hydroponics for 5 weeks and exposed to NaCl treatment for 7 days. The ABA was applied 4 or 16h before harvest. Transcripts were detected in the whole root cDNA. Results are presented as means+SEM, n=5. The expression levels were normalized to four control genes (AtGAPDH, AtActin2, AtTubulin and AtCyclophilin). Statistical significance was determined by one-way analysis of variance (ANOVA) and Tukey’s test (P≤0.05); a, b and c represent data groups that are statistically different from each other.
Fig. 2. Under low Cl– conditions, amiRNA:AtSLAH1 mutants had significantly reduced expression levels of AtSLAH1 and reduced shoot Cl– compared with null segregants. Plants were grown hydroponically for 6 weeks in BNS containing 2mM NaCl (low Cl– conditions). (A) AtSLAH1 expression in roots of all amiRNA-AtSLAH1 mutants (amiRNA:AtSLAH1_1, 2, 3 and 4) and null segregants (nulls). (B) Shoot Cl– accumulation of amiRNA-AtSLAH1 mutants and nulls under low Cl– conditions. (C) Correlation between transcript level of AtSLAH1 and shoot Cl– concentration. (D) The shoot NO3
–/Cl– ratio in all amiRNA:AtSLAH1 mutant and null segregant lines grown under low Cl– conditions. Results are mean+SEM (n>8), except (C), which is ±SEM. Statistical differences determined by one-way ANOVA and Tukey’s test (P≤0.005); a and b represent statistically significant differences between data groups.
Fig. 3. Under high Cl– conditions, 35S:AtSLAH1 overexpression lines accumulated higher shoot Cl– and showed reduced NO3
–/Cl– ratio compared with null segregants (nulls). Plants were grown hydroponically in BNS until 6 weeks old and then exposed to BNS containing 75mM NaCl (high Cl– conditions) for 7 days. (A) Semi-quantitative RT-PCR of 35S:AtSLAH1 overexpression lines and nulls. (B) Shoot Cl– concentration under high Cl– conditions. (C) Shoot NO3
–/Cl– ratio. (D) Whole shoot biomass (fresh weight) as measured after high Cl– treatment. Results are mean+SEM (n>6). Statistical differences determined by one-way ANOVA and Tukey’s test (P≤0.05); a and b represent statistically significant differences between data groups.
Fig. 4. Stelar cell type-specific overexpression of AtSLAH1 in E2586 significantly increased shoot Cl– accumulation and reduced shoot biomass under high Cl– conditions. (A) Correlation between shoot Cl– accumulation and relative expression of AtSLAH1 in GAL4:AtSLAH1 overexpression lines under high Cl– (75mM NaCl) supply. Open circles and solid line: GAL4:AtSLAH1_1; open triangle and dash line: GAL4:AtSLAH1_2. Plants were grown hydroponically in BNS for 6 weeks and then exposed to BNS containing 75mM NaCl (high Cl– conditions) for 7 days. Correlation between shoot Cl– concentration and the abundance of AtSLAH1 in GAL4:AtSLAH1_1 (R
2=0.5805, P ≤ 0.005, significant deviation from zero), GAL4:AtSLAH1_2 (R
2=0.5395, P ≤ 0.005, significant deviation from zero). (B) Whole shoot biomass (fresh weight) as measured after high Cl– treatment. Results are mean+SEM (n>6). Statistical differences determined by one-way ANOVA and Tukey’s test (P≤0.05); a and b represent statistically significant differences between data groups.
Apse,
Na+ transport in plants.
2007,
Pubmed
Blumwald,
Sodium transport in plant cells.
2000,
Pubmed
Brady,
A high-resolution root spatiotemporal map reveals dominant expression patterns.
2007,
Pubmed
Brandt,
Reconstitution of abscisic acid activation of SLAC1 anion channel by CPK6 and OST1 kinases and branched ABI1 PP2C phosphatase action.
2012,
Pubmed
,
Xenbase
Burton,
The genetics and transcriptional profiles of the cellulose synthase-like HvCslF gene family in barley.
2008,
Pubmed
Chen,
Homologue structure of the SLAC1 anion channel for closing stomata in leaves.
2010,
Pubmed
,
Xenbase
Chinnusamy,
Salt stress signaling and mechanisms of plant salt tolerance.
2006,
Pubmed
Clough,
Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana.
1998,
Pubmed
Colmenero-Flores,
Identification and functional characterization of cation-chloride cotransporters in plants.
2007,
Pubmed
,
Xenbase
Conn,
Protocol: optimising hydroponic growth systems for nutritional and physiological analysis of Arabidopsis thaliana and other plants.
2013,
Pubmed
Curtis,
A gateway cloning vector set for high-throughput functional analysis of genes in planta.
2003,
Pubmed
Davenport,
Control of sodium transport in durum wheat.
2005,
Pubmed
Demir,
Arabidopsis nanodomain-delimited ABA signaling pathway regulates the anion channel SLAH3.
2013,
Pubmed
,
Xenbase
Flowers,
Sodium chloride toxicity and the cellular basis of salt tolerance in halophytes.
2015,
Pubmed
Franco-Navarro,
Chloride regulates leaf cell size and water relations in tobacco plants.
2016,
Pubmed
Fujii,
Arabidopsis mutant deficient in 3 abscisic acid-activated protein kinases reveals critical roles in growth, reproduction, and stress.
2009,
Pubmed
Garthwaite,
Salt tolerance in wild Hordeum species is associated with restricted entry of Na+ and Cl- into the shoots.
2005,
Pubmed
Gaymard,
Identification and disruption of a plant shaker-like outward channel involved in K+ release into the xylem sap.
1998,
Pubmed
,
Xenbase
Geiger,
Stomatal closure by fast abscisic acid signaling is mediated by the guard cell anion channel SLAH3 and the receptor RCAR1.
2011,
Pubmed
,
Xenbase
Geiger,
Activity of guard cell anion channel SLAC1 is controlled by drought-stress signaling kinase-phosphatase pair.
2009,
Pubmed
,
Xenbase
Genc,
Uncoupling of sodium and chloride to assist breeding for salinity tolerance in crops.
2016,
Pubmed
Gifford,
Cell-specific nitrogen responses mediate developmental plasticity.
2008,
Pubmed
Gilliham,
The regulation of anion loading to the maize root xylem.
2005,
Pubmed
Gong,
Contrast in chloride exclusion between two grapevine genotypes and its variation in their hybrid progeny.
2011,
Pubmed
Gutermuth,
Pollen tube growth regulation by free anions depends on the interaction between the anion channel SLAH3 and calcium-dependent protein kinases CPK2 and CPK20.
2013,
Pubmed
,
Xenbase
Harrison,
A rapid and robust method of identifying transformed Arabidopsis thaliana seedlings following floral dip transformation.
2006,
Pubmed
Hedrich,
Ion channels in plants.
2012,
Pubmed
Henderson,
Grapevine and Arabidopsis Cation-Chloride Cotransporters Localize to the Golgi and Trans-Golgi Network and Indirectly Influence Long-Distance Ion Transport and Plant Salt Tolerance.
2015,
Pubmed
,
Xenbase
Henderson,
Shoot chloride exclusion and salt tolerance in grapevine is associated with differential ion transporter expression in roots.
2014,
Pubmed
Horie,
Sodium transporters in plants. Diverse genes and physiological functions.
2004,
Pubmed
Jha,
Variation in salinity tolerance and shoot sodium accumulation in Arabidopsis ecotypes linked to differences in the natural expression levels of transporters involved in sodium transport.
2010,
Pubmed
Kiegle,
Hyperpolarisation-activated calcium currents found only in cells from the elongation zone of Arabidopsis thaliana roots.
2000,
Pubmed
Kilian,
The AtGenExpress global stress expression data set: protocols, evaluation and model data analysis of UV-B light, drought and cold stress responses.
2007,
Pubmed
Köhler,
The delivery of salts to the xylem. Three types of anion conductance in the plasmalemma of the xylem parenchyma of roots of barley.
2000,
Pubmed
Köhler,
Loading of nitrate into the xylem: apoplastic nitrate controls the voltage dependence of X-QUAC, the main anion conductance in xylem-parenchyma cells of barley roots.
2002,
Pubmed
Lee,
A protein kinase-phosphatase pair interacts with an ion channel to regulate ABA signaling in plant guard cells.
2009,
Pubmed
,
Xenbase
Li,
Identification of a Stelar-Localized Transport Protein That Facilitates Root-to-Shoot Transfer of Chloride in Arabidopsis.
2016,
Pubmed
,
Xenbase
Li,
The Arabidopsis nitrate transporter NRT1.8 functions in nitrate removal from the xylem sap and mediates cadmium tolerance.
2010,
Pubmed
,
Xenbase
Lin,
Mutation of the Arabidopsis NRT1.5 nitrate transporter causes defective root-to-shoot nitrate transport.
2008,
Pubmed
,
Xenbase
Linder,
A slow anion channel in guard cells, activating at large hyperpolarization, may be principal for stomatal closing.
1992,
Pubmed
Maathuis,
Regulation of Na(+) fluxes in plants.
2014,
Pubmed
Maierhofer,
Site- and kinase-specific phosphorylation-mediated activation of SLAC1, a guard cell anion channel stimulated by abscisic acid.
2014,
Pubmed
,
Xenbase
Moya,
Chloride absorption in salt-sensitive Carrizo citrange and salt-tolerant Cleopatra mandarin citrus rootstocks is linked to water use.
2003,
Pubmed
Munns,
Salinity tolerance of crops - what is the cost?
2015,
Pubmed
Møller,
Shoot Na+ exclusion and increased salinity tolerance engineered by cell type-specific alteration of Na+ transport in Arabidopsis.
2009,
Pubmed
Müller,
Decreased capacity for sodium export out of Arabidopsis chloroplasts impairs salt tolerance, photosynthesis and plant performance.
2014,
Pubmed
Nakashima,
Three Arabidopsis SnRK2 protein kinases, SRK2D/SnRK2.2, SRK2E/SnRK2.6/OST1 and SRK2I/SnRK2.3, involved in ABA signaling are essential for the control of seed development and dormancy.
2009,
Pubmed
Negi,
CO2 regulator SLAC1 and its homologues are essential for anion homeostasis in plant cells.
2008,
Pubmed
Pitman,
Transport across plant roots.
1982,
Pubmed
Preuss,
Proton-coupled high-affinity phosphate transport revealed from heterologous characterization in Xenopus of barley-root plasma membrane transporter, HvPHT1;1.
2011,
Pubmed
,
Xenbase
Roy,
Investigating glutamate receptor-like gene co-expression in Arabidopsis thaliana.
2008,
Pubmed
,
Xenbase
Roy,
Salt resistant crop plants.
2014,
Pubmed
Schwab,
Highly specific gene silencing by artificial microRNAs in Arabidopsis.
2006,
Pubmed
Sibole,
Efficient leaf ion partitioning, an overriding condition for abscisic acid-controlled stomatal and leaf growth responses to NaCl salinization in two legumes.
2003,
Pubmed
Tavakkoli,
Additive effects of Na+ and Cl- ions on barley growth under salinity stress.
2011,
Pubmed
Teakle,
Lotus tenuis tolerates the interactive effects of salinity and waterlogging by 'excluding' Na+ and Cl- from the xylem.
2007,
Pubmed
Teakle,
Mechanisms of Cl(-) transport contributing to salt tolerance.
2010,
Pubmed
Tester,
Na+ tolerance and Na+ transport in higher plants.
2003,
Pubmed
Vahisalu,
Ozone-triggered rapid stomatal response involves the production of reactive oxygen species, and is controlled by SLAC1 and OST1.
2010,
Pubmed
Vahisalu,
SLAC1 is required for plant guard cell S-type anion channel function in stomatal signalling.
2008,
Pubmed
,
Xenbase
White,
The pathways of calcium movement to the xylem.
2001,
Pubmed
Yoshida,
The regulatory domain of SRK2E/OST1/SnRK2.6 interacts with ABI1 and integrates abscisic acid (ABA) and osmotic stress signals controlling stomatal closure in Arabidopsis.
2006,
Pubmed
Zheng,
Anion channel SLAH3 functions in nitrate-dependent alleviation of ammonium toxicity in Arabidopsis.
2015,
Pubmed
Zhu,
Regulation of ion homeostasis under salt stress.
2003,
Pubmed
