Overexpression of a novel soybean gene modulating Na and K transport enhances salt tolerance in transgenic tobacco plants

National Center for Soybean Improvement, National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
Physiologia Plantarum (Impact Factor: 3.26). 01/2011; 141(1):11-8. DOI: 10.1111/j.1399-3054.2010.01412.x
Source: PubMed

ABSTRACT Salt is an important factor affecting the growth and development of soybean in saline soil. In this study, a novel soybean gene encoding a transporter (GmHKT1) was identified and its function analyzed using transgenic plants. GmHKT1 encoded a protein of 419 amino acids, with a potential molecular mass of 47.06 kDa and a predicted pI value of 8.59. Comparison of the genomic and cDNA sequences of GmHKT1 identified no intron. The deduced amino acid sequence of GmHKT1 showed 38-49% identity with other plant HKT-like sequences. RT-PCR analysis showed that the expression of GmHKT1 was upregulated by salt stress (150 mM NaCl) in roots and leaves but not in stems. Overexpression of GmHKT1 significantly enhanced the tolerance of transgenic tobacco plants to salt stress, compared with non-transgenic plants. To investigate the role of GmHKT1 in K(+) and Na(+) transport, we compared K(+) and Na(+) accumulation in roots and shoots of wild-type and transgenic tobacco plants. The results suggested that GmHKT1 is a transporter that affected K(+) and Na(+) transport in roots and shoots, and regulated Na(+) /K(+) homeostasis in these organs. Our findings suggest that GmHKT1 plays an important role in response to salt stress and would be useful in engineering crop plants for enhanced tolerance to salt stress.

    • "Recently, a soybean novel salt-inducible gene (GmHKT1) was found to be involved in regulating Na + and K + transport, and its overexpression enhances salt tolerance in tobacco plants (Chen et al., 2011, 2014). The overexpressed transgenic plans of this gene accumulate more K + and less Na + under salt stress, supportive of the PM HKT transporters role in K + acquisition. "
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    ABSTRACT: Salt stress represents one of the environmental challenges that drastically affect plant growth and yield. Evidence suggests that glycophytes and halophytes have a salt tolerance mechanisms working at the cellular level, and the plasma membrane (PM) is believed to be one facet of the cellular mechanisms. The responses of the PM transport proteins to salinity in contrasting species/cultivars were discussed. The review provides a comprehensive overview of the recent advances describing the crucial roles that the PM transport systems have in plant adaptation to salt. Several lines of evidence were presented to demonstrate the correlation between the PM transport proteins and adaptation of plants to high salinity. How alterations in these transport systems of the PM allow plants to cope with the salt stress was also addressed. Although inconsistencies exist in some of the information related to the responses of the PM transport proteins to salinity in different species/cultivars, their key roles in adaptation of plants to high salinity is obvious and evident, and cannot be precluded. Despite the promising results, detailed investigations at the cellular/molecular level are needed in some issues of the PM transport systems in response to salinity to further evaluate their implication in salt tolerance.
    Journal of Plant Physiology 09/2014; 171(18):1787-1800. DOI:10.1016/j.jplph.2014.08.016 · 2.77 Impact Factor
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    ABSTRACT: Osmotic and ionic stresses were the primary and instant damage produced by salt stress. They can also bring about other secondary stresses. Soybean is an important economic crop and the wild soybean aroused increasing attention for its excellent performance in salt resistance. For this reason, we compared the different performances of Glycine max L. (ZH13) and Glycine soja L. (BB52) in both young and mature seedlings, hoping to clarify the specific reasons. Our research revealed that, compared to the cultivated soybean, the wild soybean was able to maintain higher water potential and relative water content (RWC), accumulate more amount of proline and glycine betaine, reduce the contents of Na(+) and Cl(-) by faster efflux, and cut down the efflux of the K(+) as well as keep higher K(+)/Na(+) ratio. And what is more is that, almost all the excel behaviors became particularly obvious under higher NaCl concentration (300 mM). Therefore, according to all the detections and comparisons, we concluded that the wild soybean had different tolerance mechanisms and better salt resistance. It should be used as eminent germplasm resource to enhance the resistant ability of cultivated soybean or even other crops.
    05/2014; 2014:651745. DOI:10.1155/2014/651745
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    ABSTRACT: Salt is an important factor affecting the growth and development of soybean in saline or alkaline soil. The aims of the present study were to identify and functionally analyse the soybean GmHKTs gene family, and to explore their roles under NaHCO3 and NaCl stresses. The GmHKTs gene family were isolated from soybean using genome sequence information. The GmHKTs gene family were further analysed for the structure and phylogenetic relationship. The expression patterns of soybean GmHKTs genes under NaHCO3 and NaCl stresses were analysed via quantitative real-time PCR. As a result, the expression level of GmHKT1;4 was extremely up regulated in root under each treatment. Overexpression of GmHKT1;4 significantly enhanced the tolerance of transgenic tobacco plants to NaHCO3 and NaCl stresses, compared with null plants. The overexpressed transgenic plants of this gene accomulated more K+ and less Na+ under salt stress, compaired with null plants. Our findings suggest that GmHKT1;4 plays an important role for regulation Na+/K+ ratio in roots under alkaline (NaHCO3) and saline (NaCl) stresses.
    Plant Growth Regulation 07/2014; 73(3). DOI:10.1007/s10725-014-9890-3 · 1.63 Impact Factor
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