Abstract
Exclusion of sodium ions from cells is one of the key salinity tolerance mechanisms in plants. The high-affinity cation transporter (HKT1;5) is located in the plasma membrane of the xylem, excluding Na+ from the parenchyma cells to reduce Na+ concentration. The regulatory mechanism and exact functions of HKT genes from different genotypic backgrounds are relatively obscure. In this study, the expression patterns of HKT1;5 in A and D genomes of wheat were investigated in root and leaf tissues of wild and domesticated genotypes using real-time PCR. In parallel, the K+/Na+ ratio was measured in salt-tolerant and salt-sensitive cultivars. Promoter analysis were applied to shed light on underlying regulatory mechanism of the HKT1;5 expression. Gene isolation and qPCR confirmed the expression of HKT1;5 in the A and D genomes of wheat ancestors (Triticum boeoticum, AbAb and Aegilops crassa, MMDD, respectively). Interestingly, earlier expression of HKT1;5 was detected in leaves compared with roots in response to salt stress. In addition, the salt-tolerant genotypes expressed HKT1;5 before salt-sensitive genotypes. Our results suggest that HKT1;5 expression follows a tissue- and genotype-specific pattern. The highest level of HKT1;5 expression was observed in the leaves of Aegilops, 6 h after being subjected to high salt stress (200 mM). Overall, the D genome allele (HKT1;5-D) showed higher expression than the A genome (HKT1;5-A) allele when subjected to a high NaCl level. We suggest that the D genome is more effective regarding Na+ exclusion. Furthermore, in silico promoter analysis showed that TaHKT1;5 genes harbor jasmonic acid response elements.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Amtmann A, Sanders D (1999) Mechanisms of Na+ uptake by plant cells. Adv Bot Res 29:75–112
Byrt CS (2008) Genes for sodium exclusion in wheat. Ph.D. thesis, University of Adelaide. Available from http://hdl.handle.net/2440/56208. Accessed 24 April 2012
Byrt CS, Platten JD, Spielmeyer W, James RA, Lagudah ES, Dennis ES, Tester M, Munns R (2007) HKT1;5-like cation transporters linked to Na+ exclusion loci in wheat, Nax2 and Kna1. Plant Physiol 143:1918–1928
Deihimi T, Niazi A, Ebrahimi M, Kajbaf K, Fanaee S, Bakhtiarizadeh MR (2012) Finding the undiscovered roles of genes: an approach using mutual ranking of coexpressed genes and promoter architecture-case study: dual roles of thaumatin like proteins in biotic and abiotic stresses. SpringerPlus 1:30
Demidchik V, Tester M (2002) Sodium fluxes through nonselective cation channels in the plasma membrane of protoplasts from Arabidopsis roots. Plant Physiol 128:379–387
Dvorak J, Akhunov ED (2005) Tempos of gene locus deletions and duplications and their relationship to recombination rate during diploid and polyploid evolution in the Aegilops–Triticum alliance. Genetics 171:323–332
Genc Y, McDonald GK, Tester M (2007) Reassessment of tissue Na+ concentration as a criterion for salinity tolerance in bread wheat. Plant Cell Environ 30:1486–1498
Ghavami F, Malboobi MA, Ghanadha MR, Yazdi-samadi B, Mozaffari J, Jafar-Aghayi M (2004) Evaluation of salt tolerance of Iranian wheat cultivars at germination and seedling stages. Iranian Journal of Agricultural Sciences 35(2):453–464
Gorham J, Win Jones RG, Bristol A (1990) Partial characterization of the trait for enhanced K+−Na+ discrimination in the D genome of wheat. Planta 180:590–597
Hauser F, Horie T (2010) A conserved primary salt tolerance mechanism mediated by HKT transporters: a mechanism for sodium exclusion and maintenance of high K+/Na+ ratio in leaves during salinity stress. Plant Cell Environ 33:552–565
Huang S, Spielmeyer W, Lagudah ES, James RA, Platten JD, Dennis ES, Munns R (2006) A sodium transporter (HKT7) is a candidate for Nax1, a gene for salt tolerance in durum wheat. Plant Physiol 142:1718–1727
James RA, Blake C, Byrt CS, Munns R (2011) Major genes for Na+ exclusion, Nax1 and Nax2 (wheat HKT1;4 and HKT1;5), decrease Na+ accumulation in bread wheat leaves under saline and waterlogged conditions. J Exp Bot 62:2939–2947
James RA, Davenport RJ, Munns R (2006) Physiological characterization of two genes for Na+ exclusion in durum wheat, Nax1 and Nax2. Plant Physiol 142:1537–1547
Kader MA, Lindberg S (2005) Uptake of sodium in protoplasts of salt-sensitive and salt-tolerant cultivars of rice Oryza sativa L. determined by the fluorescent dye SBFI. J Exp Bot 56:3149–3158
Kader MA, Seidel T, Golldack D, Lindberg S (2006) Expressions of OsHKT1, OsHKT2, and OsVHA are differentially regulated under NaCl stress in salt-sensitive and salt-tolerant rice (Oryza sativa L.) cultivars. J Exp Bot 57:4257–4268
Lehmann J, Atzorn R, Brückner C, Reinbothe S, Leopold J, Wasternack C, Parthier B (1995) Accumulation of jasmonate, abscisic acid, specific transcripts and proteins in osmotically stressed barley leaf segments. Planta 197:156–162
Lescot M, Déhais P, Thijs G, Marchal K, Moreau Y, Van de Peer Y, Rouzé P, Rombauts S (2002) PlantCARE, a database of plant cis-acting regulatory elements and a portal to tools for in silico analysis of promoter sequences. Nuc Acids Res 30:325–327
Mariño-Ramírez L, Tharakaraman K, Bodenreider O, Spouge J, Landsman D (2009) Identification of cis-regulatory elements in gene co-expression networks using A-GLAM. Meth Mol Biol 541:3–22
Pfaffl MW (2001) A new mathematical model for relative quantification in real-time RT-PCR. Nucl Acids Res 29:e45
Plett DC, Moller IS (2010) Na+ transport in glycophytic plants: what we know and would like to know. Plant Cell Environ 33:612–626
Plett D, Safwat G, Gilliham M, Moller IS, Roy S, Shirley N, Jacobs A, Johnson A, Tester M (2010) Improved salinity tolerance of rice through cell type-specific expression of AtHKT1;1. PLoS One 5:e12571
Ramezani A, Niazi A, Abolimoghadam AA, Zamani Babgohari M, Deihimi T, Ebrahimi M, Akhtardanesh H, Ebrahimie E (2012) Quantitative expression analysis of TaSOS1 and TaSOS4 genes in cultivated and wild wheat plants under salt stress. Mol Biotechnol (in press)
Rush DW, Epstein E (1976) Differences between salt-sensitive and salt-tolerant genotypes of the tomato. Plant Physiol 57:162–166
Shavrukov Y, Langridge P, Tester M (2009) Salinity tolerance and sodium exclusion in genus Triticum. Breed Sci 59:671–678
Tabatabaei SMF, Maassoumi TR (2001) Triticum boeoticum ssp thaoudar exist in Iran. Cereal Res Commun 29:121–126
Acknowledgments
The authors would like to thank the Institute of Biotechnology for supporting this research and the Bioinformatics Research Group in the College of Agriculture (Shiraz University). We thank Dr. Mehrabi (Ilam University) for kindly supplying seeds of wild genotypes for this study. We thank Mr. Amin Ramezani for help in performing the real-time PCR experiments.
Author information
Authors and Affiliations
Corresponding author
Additional information
Editor: J. Forster
Rights and permissions
About this article
Cite this article
Zamani Babgohari, M., Niazi, A., Moghadam, A.A. et al. Genome-wide analysis of key salinity-tolerance transporter (HKT1;5) in wheat and wild wheat relatives (A and D genomes). In Vitro Cell.Dev.Biol.-Plant 49, 97–106 (2013). https://doi.org/10.1007/s11627-012-9478-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11627-012-9478-4