Limits...
Two short sequences in OsNAR2.1 promoter are necessary for fully activating the nitrate induced gene expression in rice roots.

Liu X, Feng H, Huang D, Song M, Fan X, Xu G - Sci Rep (2015)

Bottom Line: We found that -129 to -1 bp region is necessary for the nitrate-induced full activation of OsNAR2.1.Part of the 20 bp fragment is commonly presented in the sequences of different promoters of both the nitrate induced NAR2 genes and nitrite reductase NIR1 genes from various higher plants.These findings thus reveal the presence of conserved cis-acting element for mediating nitrate responses in plants.

View Article: PubMed Central - PubMed

Affiliation: 1] State Key Laboratory of Crop Genetics and Germplasm Enhancement [2] MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.

ABSTRACT
Nitrate is an essential nitrogen source and serves as a signal to control growth and gene expression in plants. In rice, OsNAR2.1 is an essential partner of multiple OsNRT2 nitrate transporters for nitrate uptake over low and high concentration range. Previously, we have reported that -311 bp upstream fragment from the translational start site in the promoter of OsNAR2.1 gene is the nitrate responsive region. To identify the cis-acting DNA elements necessary for nitrate induced gene expression, we detected the expression of beta-glucuronidase (GUS) reporter in the transgenic rice driven by the OsNAR2.1 promoter with different lengths and site mutations of the 311 bp region. We found that -129 to -1 bp region is necessary for the nitrate-induced full activation of OsNAR2.1. Besides, the site mutations showed that the 20 bp fragment between -191 and -172 bp contains an enhancer binding site necessary to fully drive the OsNAR2.1 expression. Part of the 20 bp fragment is commonly presented in the sequences of different promoters of both the nitrate induced NAR2 genes and nitrite reductase NIR1 genes from various higher plants. These findings thus reveal the presence of conserved cis-acting element for mediating nitrate responses in plants.

No MeSH data available.


Analysis of the 20 bp conserved sequence in the promoters of NAR2s from different plant species.Alignment of conserved sequences in the NAR2 gene promoters from Brachypodium distachyon, Populus trichocarpa (Western Poplar), Solanum lycopersicum (Tomato), Arabidopsis thaliana, Vitis vinifera (Grape), Oryza sativa (rice). M2, mutation of non-fully conserved 8 nucleotides in the sequence between –191 bp and –172 bp of OsNAR2.1 promoter. The highly conserved nucleotides are highlighted with yellow color.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4493634&req=5

f3: Analysis of the 20 bp conserved sequence in the promoters of NAR2s from different plant species.Alignment of conserved sequences in the NAR2 gene promoters from Brachypodium distachyon, Populus trichocarpa (Western Poplar), Solanum lycopersicum (Tomato), Arabidopsis thaliana, Vitis vinifera (Grape), Oryza sativa (rice). M2, mutation of non-fully conserved 8 nucleotides in the sequence between –191 bp and –172 bp of OsNAR2.1 promoter. The highly conserved nucleotides are highlighted with yellow color.

Mentions: Since the nitrate induced GUS activity driven by the –129/–1 bp promoter was much less strong than that by the –192/–1 bp promoter of OsNAR2.1 gene (Figs 1 and 2), the –192/–129 bp region may have the nitrate enhancer binding site for activating transcriptional expression. Interestingly, we found the 20 bp fragment of 5′-GCCTCTT(GAATCCAACG)AAG-3′ at the region between –191 bp and –172 bp of the OsNAR2.1 promoter showed a high similarity with the motif 5′-GACTCTTN10AAG-3′ in the AtNIR1 promoter which is critical for nitrate inducibility27. In addition, we found that the 20 bp sequence in OsNAR2.1 promoter is relatively conserved in the putative promoters of NAR2 genes from different plant species including Arabidopsis, bean, birch and tobacco (Fig. 3).


Two short sequences in OsNAR2.1 promoter are necessary for fully activating the nitrate induced gene expression in rice roots.

Liu X, Feng H, Huang D, Song M, Fan X, Xu G - Sci Rep (2015)

Analysis of the 20 bp conserved sequence in the promoters of NAR2s from different plant species.Alignment of conserved sequences in the NAR2 gene promoters from Brachypodium distachyon, Populus trichocarpa (Western Poplar), Solanum lycopersicum (Tomato), Arabidopsis thaliana, Vitis vinifera (Grape), Oryza sativa (rice). M2, mutation of non-fully conserved 8 nucleotides in the sequence between –191 bp and –172 bp of OsNAR2.1 promoter. The highly conserved nucleotides are highlighted with yellow color.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493634&req=5

f3: Analysis of the 20 bp conserved sequence in the promoters of NAR2s from different plant species.Alignment of conserved sequences in the NAR2 gene promoters from Brachypodium distachyon, Populus trichocarpa (Western Poplar), Solanum lycopersicum (Tomato), Arabidopsis thaliana, Vitis vinifera (Grape), Oryza sativa (rice). M2, mutation of non-fully conserved 8 nucleotides in the sequence between –191 bp and –172 bp of OsNAR2.1 promoter. The highly conserved nucleotides are highlighted with yellow color.
Mentions: Since the nitrate induced GUS activity driven by the –129/–1 bp promoter was much less strong than that by the –192/–1 bp promoter of OsNAR2.1 gene (Figs 1 and 2), the –192/–129 bp region may have the nitrate enhancer binding site for activating transcriptional expression. Interestingly, we found the 20 bp fragment of 5′-GCCTCTT(GAATCCAACG)AAG-3′ at the region between –191 bp and –172 bp of the OsNAR2.1 promoter showed a high similarity with the motif 5′-GACTCTTN10AAG-3′ in the AtNIR1 promoter which is critical for nitrate inducibility27. In addition, we found that the 20 bp sequence in OsNAR2.1 promoter is relatively conserved in the putative promoters of NAR2 genes from different plant species including Arabidopsis, bean, birch and tobacco (Fig. 3).

Bottom Line: We found that -129 to -1 bp region is necessary for the nitrate-induced full activation of OsNAR2.1.Part of the 20 bp fragment is commonly presented in the sequences of different promoters of both the nitrate induced NAR2 genes and nitrite reductase NIR1 genes from various higher plants.These findings thus reveal the presence of conserved cis-acting element for mediating nitrate responses in plants.

View Article: PubMed Central - PubMed

Affiliation: 1] State Key Laboratory of Crop Genetics and Germplasm Enhancement [2] MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.

ABSTRACT
Nitrate is an essential nitrogen source and serves as a signal to control growth and gene expression in plants. In rice, OsNAR2.1 is an essential partner of multiple OsNRT2 nitrate transporters for nitrate uptake over low and high concentration range. Previously, we have reported that -311 bp upstream fragment from the translational start site in the promoter of OsNAR2.1 gene is the nitrate responsive region. To identify the cis-acting DNA elements necessary for nitrate induced gene expression, we detected the expression of beta-glucuronidase (GUS) reporter in the transgenic rice driven by the OsNAR2.1 promoter with different lengths and site mutations of the 311 bp region. We found that -129 to -1 bp region is necessary for the nitrate-induced full activation of OsNAR2.1. Besides, the site mutations showed that the 20 bp fragment between -191 and -172 bp contains an enhancer binding site necessary to fully drive the OsNAR2.1 expression. Part of the 20 bp fragment is commonly presented in the sequences of different promoters of both the nitrate induced NAR2 genes and nitrite reductase NIR1 genes from various higher plants. These findings thus reveal the presence of conserved cis-acting element for mediating nitrate responses in plants.

No MeSH data available.