The sugar beet gene encoding the sodium/proton exchanger 1  (BvNHX1) is regulated by a MYB transcription factor.
Sodium/proton exchangers (NHX) are key players in the plant response to salinity and have a central role in establishing ion homeostasis. NHXs can be localized in the tonoplast or plasma membranes, where they exchange sodium ions for protons, resulting in sodium ions being removed from the cytosol into the vacuole or extracellular space. The expression of most plant NHX genes is modulated by exposure of the organisms to salt stress or water stress. We explored the regulation of the vacuolar NHX1 gene from the salt-tolerant sugar beet plant (BvNHX1) using Arabidopsis plants transformed with an array of constructs of BvHNX1::GUS, and the expression patterns were characterized using histological and quantitative assays. The 5 UTR of BvNHX1, including its intron, does not modulate the activity of the promoter. Serial deletions show that a 337 bp promoter fragment sufficed for driving activity that indistinguishable from that of the full-length (2,464 bp) promoter. Mutating four putative cis-acting elements within the 337 bp promoter fragment revealed that MYB transcription factor(s) are involved in the activation of the expression of BvNHX1 upon exposure to salt and water stresses. Gel mobility shift assay confirmed that the WT but not the mutated MYB binding site is bound by nuclear protein extracted from salt-stressed Beta vulgaris leaves.
Adler
Guy
G
Department of Life Sciences, The Doris and Bertie Black Center for Bioenergetics in Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Blumwald
Eduardo
E
Bar-Zvi
Dudy
D
D020121:5' Untranslated Regions; D001483:Base Sequence; D027461:Beta vulgaris / Q000235:genetics*; D003001:Cloning, Molecular; D017931:DNA Primers; D024202:Electrophoretic Mobility Shift Assay; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D011401:Promoter Regions, Genetic; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*
D020121:5' Untranslated Regions; D017931:DNA Primers; D017923:Sodium-Hydrogen Exchangers; D014157:Transcription Factors
Curr Opin Plant Biol. 2003 Oct;6(5):441-5
12972044
Plant J. 2000 Nov;24(4):511-22
11115132
Plant J. 2004 Dec;40(5):744-51
15546357
Plant Cell. 2003 Jan;15(1):63-78
12509522
Plant J. 2005 Dec;44(5):826-39
16297073
Curr Opin Plant Biol. 2006 Oct;9(5):544-9
16877030
Plant Physiol. 1995 Oct;109(2):549-556
12228611
Plant Mol Biol. 2006 Jan;60(1):107-24
16463103
Plant Physiol. 1985 May;78(1):163-7
16664191
Plant Physiol. 1987 Sep;85(1):30-3
16665675
Plant J. 1998 Dec;16(6):735-43
10069079
Plant Physiol. 1990 Dec;94(4):1788-94
16667917
Plant J. 2003 Oct;36(2):229-39
14535887
Biochemistry (Mosc). 2005 Jan;70(1):100-7
15701055
Plant Physiol Biochem. 2008 Feb;46(2):117-26
18061467
Annu Rev Plant Biol. 2006;57:781-803
16669782
FEBS Lett. 2007 May 25;581(12):2247-54
17459382
Plant Mol Biol. 2001 May;46(1):35-42
11437248
Planta. 1996;199(4):515-9
8818291
Plant Mol Biol. 2002 Oct;50(3):543-50
12369629
Physiol Plant. 2002 Oct;116(2):206-212
12354197
Trends Plant Sci. 2001 Feb;6(2):66-71
11173290
Curr Opin Plant Biol. 2006 Apr;9(2):180-8
16458043
J Exp Bot. 2004 Jan;55(395):225-36
14673035
Annu Rev Plant Physiol Plant Mol Biol. 2000 Jun;51:463-499
15012199
Plant Physiol. 1987 Apr;83(4):884-7
16665356
Trends Plant Sci. 2005 Dec;10(12):615-20
16280254
Plant J. 2006 May;46(4):573-92
16640595
Plant Physiol. 2004 Jul;135(3):1697-709
15247402
EMBO J. 1994 Nov 15;13(22):5383-92
7957104
Trends Plant Sci. 2004 Dec;9(12):591-6
15564126
J Exp Bot. 2006;57(5):1181-99
16513813
Plant Cell Physiol. 2001 May;42(5):451-61
11382810
Annu Rev Plant Biol. 2002;53:247-73
12221975
Curr Top Microbiol Immunol. 2008;326:v-vii
18630743
Plant Cell Environ. 2002 Feb;25(2):239-250
11841667
Trends Plant Sci. 2005 Feb;10(2):88-94
15708346
Plant Physiol. 2006 Apr;140(4):1437-50
16500996
Curr Opin Cell Biol. 2000 Aug;12(4):431-4
10873827
Plant Biotechnol J. 2008 May;6(4):368-78
18363631
Genes Genet Syst. 2005 Apr;80(2):121-8
16172524
BMC Genomics. 2006 May 19;7:120
16712733
Curr Opin Cell Biol. 2001 Aug;13(4):399-404
11454443
DNA Seq. 2005 Oct;16(5):352-7
16243725
BMC Plant Biol. 2007 Apr 05;7:18
17411438
Proc Natl Acad Sci U S A. 1988 Oct;85(19):7089-93
2902624
Curr Opin Plant Biol. 2003 Oct;6(5):410-7
12972040
Nucleic Acids Res. 1999 Jan 1;27(1):297-300
9847208
Plant Cell Physiol. 2004 May;45(5):600-7
15169942
Plant J. 2002 Jun;30(5):529-39
12047628