OsHKT1;5;SKC1

Gene Details

MSU gene ID: LOC_Os01g20160
RAPdb gene ID: Os01g0307500
Gene Symbol: OsHKT1 5 SKC1 OsHKT8 OsHK1 5
Genome: MSU7 , IRGSP-1.0
Species: Oryza sativa

Functional Descriptions

Here we present a review on vital physiological functions of HKT transporters including AtHKT1;1 and OsHKT1;5 in preventing shoot Na(+) over-accumulation by mediating Na(+) exclusion from xylem vessels in the presence of a large amount of Na(+) thereby protecting leaves from salinity stress.
We previously mapped a rice QTL, SKC1, that maintained K(+) homeostasis in the salt-tolerant variety under salt stress, consistent with the earlier finding that K(+) homeostasis is important in salt tolerance.
Physiological analysis suggested that SKC1 is involved in regulating K(+)/Na(+) homeostasis under salt stress, providing a potential tool for improving salt tolerance in crops.
SKC1 is preferentially expressed in the parenchyma cells surrounding the xylem vessels.
The association of leaf Na+ concentrations with cultivar-groups was very weak, but association with the OsHKT1;5 allele was generally strong.
Seven major and three minor alleles of OsHKT1;5 were identified, and their comparisons with the leaf Na+ concentration showed that the Aromatic allele conferred the highest exclusion and the Japonica allele the least.
In addition, lower expression of OsHKT1;5 and OsSOS1 in old leaves may decrease frequency of retrieving Na+ from old leaf cells.
To understand the molecular basis of this QTL, we isolated the SKC1 gene by map-based cloning and found that it encoded a member of HKT-type transporters.
Voltage-clamp analysis showed that SKC1 protein functions as a Na(+)-selective transporter.
For OsHKT1;5, both transcript abundance and protein structural features within the selectivity filter could control shoot Na(+) accumulation in a range of rice varieties.
OsHKT1;5 mediates Na(+) exclusion in the vasculature to protect leaf blades and reproductive tissues from salt toxicity in rice.
Additionally, direct introduction of (22) Na(+) tracer to leaf sheaths also demonstrated the involvement of OsHKT1;5 in xylem Na(+) unloading in leaf sheaths.
Together with the characteristic (22) Na(+) allocation in the blade of the developing immature leaf in the mutants, these results suggest a novel function of OsHKT1;5 in mediating Na(+) exclusion in the phloem to prevent Na(+) transfer to young leaf blades.
Our findings further demonstrate that the function of OsHKT1;5 is crucial over growth stages of rice, including the protection of the next generation seeds as well as of vital leaf blades under salt stress.
Immuno-staining using an anti-OsHKT1;5 peptide antibody indicated that OsHKT1;5 is localized in cells adjacent to the xylem in roots.
Furthermore, OsHKT1;5 was indicated to present in the plasma membrane and found to localize also in the phloem of diffuse vascular bundles in basal nodes.
Salt tolerance QTL analysis of rice has revealed that the SKC1 locus, which is involved in a higher K(+) /Na(+) ratio in shoots, corresponds to the OsHKT1;5 gene encoding a Na(+) -selective transporter.
However, physiological roles of OsHKT1;5 in rice exposed to salt stress remain elusive and no OsHKT1;5 gene disruption mutants have been characterized to date.
Salt stress-induced increases in the OsHKT1;5 transcript was observed in roots and basal stems including basal nodes.
We also report the development and validation of a new Cleavage Amplified Polymorphic Sequence (CAPS) marker (OsHKT1;5V395) that targets a codon in the sodium transporter gene OsHKT1;5 (Saltol/SKC1 locus) that is associated with sodium transport rates in the above rice landraces.
Analysis of genetic diversity and population structure using SSR markers and validation of a Cleavage Amplified Polymorphic Sequences (CAPS) marker involving the sodium transporter OsHKT1;5 in saline tolerant rice (Oryza sativa L.) landraces.
Allelic variation in rice OsHKT1;5 sequence in specific landraces (Nona Bokra OsHKT1;5-NB/Nipponbare OsHKT1;5-Ni) correlates with variation in salt tolerance.
In rice, the OsHKT1;5 gene has been reported to be a critical determinant of salt tolerance.
Changes in Expression Level of OsHKT1;5 Alters Activity of Membrane Transporters Involved in K + and Ca 2+ Acquisition and Homeostasis in Salinized Rice Roots.
Furthermore, expression analysis suggested that OsGrx_C7 acted as positive regulator of salt tolerance by reinforcing the expression of transporters (OsHKT2;1, OsHKT1;5 and OsSOS1) engaged in Na+ homeostasis in overexpressing plants.
Intriguingly, salt stress facilitates the nuclear relocation of OsDNAJ15 so that it can interact with OsBAG4, and OsDNAJ15 and OsBAG4 synergistically facilitate the DNA-binding activity of OsMYB106 to positively regulate the expression of OsHKT1;5.
Using a previously generated high-throughput activation tagging-based T-DNA insertion mutant pool, we isolated a mutant exhibiting salt stress-sensitive phenotype, caused by a reduction in OsHKT1;5 transcripts.
Plasma membrane-localized Hsp40/DNAJ chaperone protein facilitates OsSUVH7-OsBAG4-OsMYB106 transcriptional complex formation for OsHKT1;5 activation.
The real-time quantitative PCR (qRT-PCR) and transcriptome analysis revealed that OsWRKY54 regulated the expression of some essential genes related to salt tolerance, such as OsNHX4 and OsHKT1;5.

Functional Keywords

Literature and News

Gene Resources

Sequences

cDNA Sequence

>LOC_Os01g20160.1
GCTGTTGCTCTTGTTCACTTGTGCTCACAGCACCTGGTAACCCCACATACAGTGATCACACAACAAACAATATCTGTTGTTTGTGTATAAATAGCCCTAACATGGCTTCCTAATTCCTATAAACAACAAGTGTGAGAAAACCCAAGAACGAAACACATAGGAGAGAAATGAGTTCTCTGGATGCCACTACTCCTAGATATGACGAGTTTAAAAGGATCTACCACCTTTTCCTTTTCCATGCACACCCATTCTGGCTCCAACTGCTGTACTTCCTCTTCATCTCCCTCTTGGGTTTCTTGATGCTGAAAGCTCTGCCGATGAAGACCAGCATGGTGCCGAGGCCCATGGACTTGGACCTGATCTTCACGTCGGTGTCGGCGACGACGGTGTCGAGCATGGTCGCCGTCGAGATGGAGTCCTTCTCCAACTCCCAGCTCCTCCTCATCACCCTCCTCATGCTGCTTGGTGGTGAGGTCTTCACCAGCATCCTTGGCCTCTACTTCACCAACGCCAAGTACTCCTCCAAGATGATAGCAACCTTACCTGATGATGACGACCATGGTGGCAGTGGCAAACCACCACCACCAACGACGTCACCTTCGTCTACCCTAGTGGAGCTCGAGCTCGCTCCTCCCATGGACGTCGTCGTCGTCAACCCTACCACCACTGCGACGACGCACGACGAGGTAGAGCTAGGGTTAGGACGTCGGAACAAGCGCGGCTGCACCTGCACTACTACTCACACGTCGTCGTCATCATCGGCATCGAAGACGACGACGACGAGGCTACTGATGTTCGTGGTGATGGGGTACCACGCGGTGGTGCACGTCGCCGGGTACACGGCCATCGTCGTGTACCTCAGCGCCGTCGGCGGCGCGGGGGCGGTGGTCGCCGGGAAGGGGATCAGCGCGCACACGTTCGCCATCTTCACCGTCGTCTCGACGTTCGCCAACTGCGGGTTCGTGCCGACGAACGAAGGGATGGTGTCGTTCAGGTCGTTCCCGGGGCTCCTCCTCCTCGTCATGCCGCACGTCCTCCTCGGGAACACGCTCTTCCCGGTCTTCCTCAGGCTGGCCATCGCCGCGCTCGAGAGGGTCACCGGGTGGCCGGAGCTCGGCGAGCTCCTGATCCGGCGGCGGAGGGGCGGCGGCGAGGGCTACCACCACCTGTTGCCGAGCTCGCGCACGCGGTTCCTGGCCCTCACCGTGGCCGTGCTCGTGGTGGCGCAGCTGGCGCTCTTCTGCGCCATGGAGTGGGGCTCCGACGGGCTGCGGGGGCTCACCGCGGGCCAGAAGCTCGTCGGCGCGCTCTTCATGGCGGTCAACTCGAGGCACTCCGGTGAGATGGTGCTCGACCTCTCCACCGTGTCGTCGGCCGTCGTCGTGCTCTACGTGGTGATGATGTACCTGCCACCTTACACCACTTTCGTACCTGTCCAAGACAAACACCAGCAAACGGGAGCACAGTCCGGGCAGGAGGGCAGCAGCAGCAGCAGCATATGGCAGAAGCTGCTCATGTCGCCGCTCTCGTGCCTAGCCATCTTCATCGTCGTCATCTGCATCACGGAGCGGCGGCAAATCGCCGACGACCCCATCAACTACAGCGTCCTCAACATCGTCGTCGAGGTTATCAGTGCGTATGGCAATGTGGGGTTCAGCACGGGGTACAGCTGCGCGAGGCAGGTGAGGCCCGACGGCAGCTGCAGAGACCTGTGGGTTGGCTTCTCAGGGAAGTGGAGCAAACAAGGGAAGCTCACTCTCATGGCCGTCATGTTCTACGGCAGGCTCAAGAAGTTCAGCCTGCACGGTGGTCAGGCATGGAAGATAGAATAACGCCTAACTGCAAGCACCCATGCATGCATGACAACTTCGTTACTAATTAATGGGGCATTTCAGCCGGCCGCCGTACTAGACTACAAGAGATCGATCGATAGGTCTCCCCTCCTAAAACTCCTCCTTAATCTGATCTCCACGAGTTCTTGATCAGGGTTACTTATATATTATAAAGGAATGATCAGATAAATATATGTCTATATCAGGATCTGGTCGATCTCTAGATATCTGTCTTTTTTTTTTTTGGGTAATGCATGTAAGCAAGTAGCAATTGCTAGACATATATATGTGTTAGCTTACGAGAGTATATACTGGCGCTTGAGTCGTGATGA

CDS Sequence

>LOC_Os01g20160.1
ATGAGTTCTCTGGATGCCACTACTCCTAGATATGACGAGTTTAAAAGGATCTACCACCTTTTCCTTTTCCATGCACACCCATTCTGGCTCCAACTGCTGTACTTCCTCTTCATCTCCCTCTTGGGTTTCTTGATGCTGAAAGCTCTGCCGATGAAGACCAGCATGGTGCCGAGGCCCATGGACTTGGACCTGATCTTCACGTCGGTGTCGGCGACGACGGTGTCGAGCATGGTCGCCGTCGAGATGGAGTCCTTCTCCAACTCCCAGCTCCTCCTCATCACCCTCCTCATGCTGCTTGGTGGTGAGGTCTTCACCAGCATCCTTGGCCTCTACTTCACCAACGCCAAGTACTCCTCCAAGATGATAGCAACCTTACCTGATGATGACGACCATGGTGGCAGTGGCAAACCACCACCACCAACGACGTCACCTTCGTCTACCCTAGTGGAGCTCGAGCTCGCTCCTCCCATGGACGTCGTCGTCGTCAACCCTACCACCACTGCGACGACGCACGACGAGGTAGAGCTAGGGTTAGGACGTCGGAACAAGCGCGGCTGCACCTGCACTACTACTCACACGTCGTCGTCATCATCGGCATCGAAGACGACGACGACGAGGCTACTGATGTTCGTGGTGATGGGGTACCACGCGGTGGTGCACGTCGCCGGGTACACGGCCATCGTCGTGTACCTCAGCGCCGTCGGCGGCGCGGGGGCGGTGGTCGCCGGGAAGGGGATCAGCGCGCACACGTTCGCCATCTTCACCGTCGTCTCGACGTTCGCCAACTGCGGGTTCGTGCCGACGAACGAAGGGATGGTGTCGTTCAGGTCGTTCCCGGGGCTCCTCCTCCTCGTCATGCCGCACGTCCTCCTCGGGAACACGCTCTTCCCGGTCTTCCTCAGGCTGGCCATCGCCGCGCTCGAGAGGGTCACCGGGTGGCCGGAGCTCGGCGAGCTCCTGATCCGGCGGCGGAGGGGCGGCGGCGAGGGCTACCACCACCTGTTGCCGAGCTCGCGCACGCGGTTCCTGGCCCTCACCGTGGCCGTGCTCGTGGTGGCGCAGCTGGCGCTCTTCTGCGCCATGGAGTGGGGCTCCGACGGGCTGCGGGGGCTCACCGCGGGCCAGAAGCTCGTCGGCGCGCTCTTCATGGCGGTCAACTCGAGGCACTCCGGTGAGATGGTGCTCGACCTCTCCACCGTGTCGTCGGCCGTCGTCGTGCTCTACGTGGTGATGATGTACCTGCCACCTTACACCACTTTCGTACCTGTCCAAGACAAACACCAGCAAACGGGAGCACAGTCCGGGCAGGAGGGCAGCAGCAGCAGCAGCATATGGCAGAAGCTGCTCATGTCGCCGCTCTCGTGCCTAGCCATCTTCATCGTCGTCATCTGCATCACGGAGCGGCGGCAAATCGCCGACGACCCCATCAACTACAGCGTCCTCAACATCGTCGTCGAGGTTATCAGTGCGTATGGCAATGTGGGGTTCAGCACGGGGTACAGCTGCGCGAGGCAGGTGAGGCCCGACGGCAGCTGCAGAGACCTGTGGGTTGGCTTCTCAGGGAAGTGGAGCAAACAAGGGAAGCTCACTCTCATGGCCGTCATGTTCTACGGCAGGCTCAAGAAGTTCAGCCTGCACGGTGGTCAGGCATGGAAGATAGAATAA

Protein Sequence

>LOC_Os01g20160.1
MSSLDATTPRYDEFKRIYHLFLFHAHPFWLQLLYFLFISLLGFLMLKALPMKTSMVPRPMDLDLIFTSVSATTVSSMVAVEMESFSNSQLLLITLLMLLGGEVFTSILGLYFTNAKYSSKMIATLPDDDDHGGSGKPPPPTTSPSSTLVELELAPPMDVVVVNPTTTATTHDEVELGLGRRNKRGCTCTTTHTSSSSSASKTTTTRLLMFVVMGYHAVVHVAGYTAIVVYLSAVGGAGAVVAGKGISAHTFAIFTVVSTFANCGFVPTNEGMVSFRSFPGLLLLVMPHVLLGNTLFPVFLRLAIAALERVTGWPELGELLIRRRRGGGEGYHHLLPSSRTRFLALTVAVLVVAQLALFCAMEWGSDGLRGLTAGQKLVGALFMAVNSRHSGEMVLDLSTVSSAVVVLYVVMMYLPPYTTFVPVQDKHQQTGAQSGQEGSSSSSIWQKLLMSPLSCLAIFIVVICITERRQIADDPINYSVLNIVVEVISAYGNVGFSTGYSCARQVRPDGSCRDLWVGFSGKWSKQGKLTLMAVMFYGRLKKFSLHGGQAWKIE*