Limits...
The sugar beet gene encoding the sodium/proton exchanger 1 (BvNHX1) is regulated by a MYB transcription factor.

Adler G, Blumwald E, Bar-Zvi D - Planta (2010)

Bottom Line: 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 5 UTR of BvNHX1, including its intron, does not modulate the activity of the promoter.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences, The Doris and Bertie Black Center for Bioenergetics in Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.

ABSTRACT
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.

Show MeSH

Related in: MedlinePlus

Expression pattern of the full-size BvNHX1 promoter. a Scheme of full-size BvNHX1 promoter structure. Upstream promoter sequence, 5′ UTR, and intron are marked in gray, black and white, respectively. Nucleotides are numbered in according to the translation start ATG start sequence. b–iArabidopsis plants expressing the 2,487 bp BvNHX1::GUS constructs were grown under non-stressed conditions. Histochemical staining of GUS was performed as described in “Materials and methods”. b Shoot of soil grown plant. c Section of a mature leaf. d Close-up of the edge of the leaf shown in (c). e Primary roots. f Root hairs. g Emerging lateral root. h Flower. i Silique
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2872020&req=5

Fig1: Expression pattern of the full-size BvNHX1 promoter. a Scheme of full-size BvNHX1 promoter structure. Upstream promoter sequence, 5′ UTR, and intron are marked in gray, black and white, respectively. Nucleotides are numbered in according to the translation start ATG start sequence. b–iArabidopsis plants expressing the 2,487 bp BvNHX1::GUS constructs were grown under non-stressed conditions. Histochemical staining of GUS was performed as described in “Materials and methods”. b Shoot of soil grown plant. c Section of a mature leaf. d Close-up of the edge of the leaf shown in (c). e Primary roots. f Root hairs. g Emerging lateral root. h Flower. i Silique

Mentions: A second round of walking was preformed using the gene-specific primers BvP1 and BvP2 which were designed from sequences in the 704 bp fragment and yielded a 911 bp DNA fragment. The final combined promoter sequence comprised 2,464 bp upstream the translation start codon, composed of 1,378 bp promoter, 304 bp 5′ UTR exon I, 605 bp intron and 200 bp 5′ UTR exon II (Fig. 1a).Fig. 1


The sugar beet gene encoding the sodium/proton exchanger 1 (BvNHX1) is regulated by a MYB transcription factor.

Adler G, Blumwald E, Bar-Zvi D - Planta (2010)

Expression pattern of the full-size BvNHX1 promoter. a Scheme of full-size BvNHX1 promoter structure. Upstream promoter sequence, 5′ UTR, and intron are marked in gray, black and white, respectively. Nucleotides are numbered in according to the translation start ATG start sequence. b–iArabidopsis plants expressing the 2,487 bp BvNHX1::GUS constructs were grown under non-stressed conditions. Histochemical staining of GUS was performed as described in “Materials and methods”. b Shoot of soil grown plant. c Section of a mature leaf. d Close-up of the edge of the leaf shown in (c). e Primary roots. f Root hairs. g Emerging lateral root. h Flower. i Silique
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2872020&req=5

Fig1: Expression pattern of the full-size BvNHX1 promoter. a Scheme of full-size BvNHX1 promoter structure. Upstream promoter sequence, 5′ UTR, and intron are marked in gray, black and white, respectively. Nucleotides are numbered in according to the translation start ATG start sequence. b–iArabidopsis plants expressing the 2,487 bp BvNHX1::GUS constructs were grown under non-stressed conditions. Histochemical staining of GUS was performed as described in “Materials and methods”. b Shoot of soil grown plant. c Section of a mature leaf. d Close-up of the edge of the leaf shown in (c). e Primary roots. f Root hairs. g Emerging lateral root. h Flower. i Silique
Mentions: A second round of walking was preformed using the gene-specific primers BvP1 and BvP2 which were designed from sequences in the 704 bp fragment and yielded a 911 bp DNA fragment. The final combined promoter sequence comprised 2,464 bp upstream the translation start codon, composed of 1,378 bp promoter, 304 bp 5′ UTR exon I, 605 bp intron and 200 bp 5′ UTR exon II (Fig. 1a).Fig. 1

Bottom Line: 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 5 UTR of BvNHX1, including its intron, does not modulate the activity of the promoter.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences, The Doris and Bertie Black Center for Bioenergetics in Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.

ABSTRACT
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.

Show MeSH
Related in: MedlinePlus