Rice K+ uptake channel OsAKT1 is sensitive to salt stress

Fuchs, Ines; Stölzle, Sonja; Ivashikina, Natalya; Hedrich, Rainer

doi:10.1007/s00425-004-1437-9

Cited by 144 publications

(113 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…S11). Previous electrophysiological analyses suggested that AtKC1 function in rice is weak (Fuchs et al, 2005;Li et al, 2014), although two putative AtKC1 homologs have been found in the rice genome (Supplemental Fig. S11).…”

Section: Discussion Physiological Function Of Atkc1 In Plant Cellsmentioning

confidence: 99%

AtKC1 and CIPK23 Synergistically Modulate AKT1-Mediated Low-Potassium Stress Responses in Arabidopsis

et al. 2016

View full text Add to dashboard Cite

In Arabidopsis (Arabidopsis thaliana), the Shaker K + channel AKT1 conducts K + uptake in root cells, and its activity is regulated by CBL1/9-CIPK23 complexes as well as by the AtKC1 channel subunit. CIPK23 and AtKC1 are both involved in the AKT1-mediated low-K + (LK) response; however, the relationship between them remains unclear. In this study, we screened suppressors of low-K + sensitive [lks1 (cipk23)] and isolated the suppressor of lks1 (sls1) mutant, which suppressed the leaf chlorosis phenotype of lks1 under LK conditions. Map-based cloning revealed a point mutation in AtKC1 of sls1 that led to an amino acid substitution (G322D) in the S6 region of AtKC1. The G322D substitution generated a gain-of-function mutation, AtKC1 D , that enhanced K + uptake capacity and LK tolerance in Arabidopsis. Structural prediction suggested that glycine-322 is highly conserved in K + channels and may function as the gating hinge of plant Shaker K + channels. Electrophysiological analyses revealed that, compared with wild-type AtKC1, AtKC1 D showed enhanced inhibition of AKT1 activity and strongly reduced K + leakage through AKT1 under LK conditions. In addition, phenotype analysis revealed distinct phenotypes of lks1 and atkc1 mutants in different LK assays, but the lks1 atkc1 double mutant always showed a LK-sensitive phenotype similar to that of akt1. This study revealed a link between CIPK-mediated activation and AtKC1-mediated modification in AKT1 regulation. CIPK23 and AtKC1 exhibit distinct effects; however, they act synergistically and balance K + uptake/leakage to modulate AKT1-mediated LK responses in Arabidopsis.

show abstract

Section: Discussion Physiological Function Of Atkc1 In Plant Cellsmentioning

confidence: 99%

AtKC1 and CIPK23 Synergistically Modulate AKT1-Mediated Low-Potassium Stress Responses in Arabidopsis

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Other than these instances, little evidence for Na + -coupled K + uptake exists in terrestrial plants Rodríguez-Navarro and Rubio 2006;Corratgé-Faillie et al 2010;Schulze et al 2012), although it may play a significant role in aquatic angiosperms and algae . A far more common observation is that Na + , at already modest (below-saline) concentrations, inhibits K + -influx systems, both in the high-and low-affinity transport ranges for K + (Rains and Epstein 1967a, b, c;Cheeseman 1982;Jeschke 1982;Kochian et al 1985;Benlloch et al 1994;Schachtman and Schroeder 1994;Santa-María et al 1997;Flowers and Hajibagheri 2001;Fuchs et al 2005;Martínez-Cordero et al 2005;Kronzucker et al 2006Kronzucker et al , 2008Nieves-Cordones et al 2007;Wang et al 2007), and can, additionally, stimulate K + efflux (Shabala et al 2006;Britto et al 2010;Coskun et al 2013), thus depressing K + -utilization efficiency in a two-pronged fashion.…”

Section: Sodium As a Nutrientmentioning

confidence: 99%

“…Figure 1 summarizes the key events that are expected to lead to compromised cytosolic K + homeostasis in typical root cells. Na + can directly inhibit high-affinity K + transporters of the KUP/HAK/KT family (SantaMaría et al 1997;Quintero and Blatt 1997;Fu and Luan 1998;Senn et al 2001) and Shaker-type K + channels (Thiel and Blatt 1991;Qi and Spalding 2004;Fuchs et al 2005;Wang et al 2007). Moreover, transcript abundances of both KUP/HAK/KT transporters (Su et al 2002;Nieves-Cordones et al 2007) and Shaker-type K + channels (Su et al 2001;Golldack et al 2003;Pilot et al 2003) can be affected negatively by NaCl.…”

Section: Sodium Toxicitymentioning

confidence: 99%

Sodium as nutrient and toxicant

et al. 2013

View full text Add to dashboard Cite

Background Sodium (Na + ) is one of the most intensely researched ions in plant biology and has attained a reputation for its toxic qualities. Following the principle of Theophrastus Bombastus von Hohenheim (Paracelsus), Na + is, however, beneficial to many species at lower levels of supply, and in some, such as certain C4 species, indeed essential. Scope Here, we review the ion's divergent roles as a nutrient and toxicant, focusing on growth responses, membrane transport, stomatal function, and paradigms of ion accumulation and sequestration. We examine connections between the nutritional and toxic roles throughout, and place special emphasis on the relationship of Na + to plant potassium (K + ) relations and homeostasis. Conclusions Our review investigates intriguing connections and disconnections between Na + nutrition and toxicity, and concludes that several leading paradigms in the field, such as on the roles of Na + influx and tissue accumulation or the cytosolic K + /Na + ratio in the development of toxicity, are currently insufficiently substantiated and require a new, critical approach.

show abstract

“…Elevated cytoplasmic Na 1 impaired the K 1 permeability mediated by AKT1 (Qi and Spalding, 2004). OsAKT1 is also reported to represent the dominant salt-sensitive K 1 uptake channel in rice roots (Fuchs et al, 2005), and the expression of OsAKT1 is regulated differently in salt-sensitive and salt-tolerant cultivars of rice (Golldack et al, 2003). These results suggest the inhibition of K 1 uptake mediated by these channels as a possible cause of toxicity of Na 1 .…”

mentioning

confidence: 99%

Rice Shaker Potassium Channel OsKAT1 Confers Tolerance to Salinity Stress on Yeast and Rice Cells

Obata

Kitamoto²,

Nakamura³

et al. 2007

Plant Physiol.

145

View full text Add to dashboard Cite

We screened a rice (Oryza sativa L. 'Nipponbare') full-length cDNA expression library through functional complementation in yeast (Saccharomyces cerevisiae) to find novel cation transporters involved in salt tolerance. We found that expression of a cDNA clone, encoding the rice homolog of Shaker family K 1 channel KAT1 (OsKAT1), suppressed the salt-sensitive phenotype of yeast strain G19 (Dena1-4), which lacks a major component of Na 1 efflux. It also suppressed a K 1 -transport-defective phenotype of yeast strain CY162 (Dtrk1Dtrk2), suggesting the enhancement of K 1 uptake by OsKAT1. By the expression of OsKAT1, the K 1 contents of salt-stressed G19 cells increased during the exponential growth phase. At the linear phase, however, OsKAT1-expressing G19 cells accumulated less Na 1 than nonexpressing cells, but almost the same K 1 . The cellular Na 1 to K 1 ratio of OsKAT1-expressing G19 cells remained lower than nonexpressing cells under saline conditions. Rice cells overexpressing OsKAT1 also showed enhanced salt tolerance and increased cellular K 1 content. These functions of OsKAT1 are likely to be common among Shaker K 1 channels because OsAKT1 and Arabidopsis (Arabidopsis thaliana) KAT1 were able to complement the salt-sensitive phenotype of G19 as well as OsKAT1. The expression of OsKAT1 was restricted to internodes and rachides of wild-type rice, whereas other Shaker family genes were expressed in various organs. These results suggest that OsKAT1 is involved in salt tolerance of rice in cooperation with other K 1 channels by participating in maintenance of cytosolic cation homeostasis during salt stress and thus protects cells from Na 1 .

show abstract

Rice K+ uptake channel OsAKT1 is sensitive to salt stress

Cited by 144 publications

References 46 publications

AtKC1 and CIPK23 Synergistically Modulate AKT1-Mediated Low-Potassium Stress Responses in Arabidopsis

AtKC1 and CIPK23 Synergistically Modulate AKT1-Mediated Low-Potassium Stress Responses in Arabidopsis

Sodium as nutrient and toxicant

Rice Shaker Potassium Channel OsKAT1 Confers Tolerance to Salinity Stress on Yeast and Rice Cells

Contact Info

Product

Resources

About