Root nitrate response of Col-0 plants and tga1/tga4 mutant plants
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE43011 | GEO | 2013/03/31
SECONDARY ACCESSION(S): PRJNA184053
REPOSITORIES: GEO
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Project description:Nitrate regulates plant growth and development and acts as a potent signal to control gene expression in Arabidopsis. Using an integrative bioinformatics approach we identified TGA1 and TGA4 as putative regulatory factors that mediate nitrate responses in Arabidopsis thaliana roots. We showed that both TGA1 and TGA4 mRNAs accumulate strongly and quickly after nitrate treatments in root organs in a tissue-specific manner. Phenotypic analysis of tga1/tga4 double mutant plants indicated that TGA1 and TGA4 are necessary for nitrate modulation of both primary and lateral root growth. Global gene expression analysis revealed that 97% of the genes with altered expression in tga1/tga4 double mutant plants are regulated by nitrate treatments indicating these transcription factors have a specific role in nitrate responses in Arabidopsis root organs. Among the nitrate-responsive genes that depend on TGA1/TGA4 for normal regulation of gene expression, we found nitrate transporters NRT2.1, NRT2.2 and nitrite reductase (NIR) genes. Specific binding of TGA1 to its cognate DNA sequence on the target gene promoters was confirmed by chromatin immunoprecipitation assays. These results identify TGA1 and TGA4 as important regulatory factors of the nitrate response in Arabidopsis roots. Arabidopsis seedlings of the Col-0 and tga1/tga4 genotypes were grown on hydroponic medium containing 1X MS salts without Nitrogen, supplemented with 0.5 mM ammonium succinate as Nitrogen source and 3 mM sucrose on a Percival chamber under a photoperiod of 16 hours of light (100 ?E/m2/sec) and 8 hours of dark at 22°C for 14 days. The plants were treated at the onset of the light cycle with 5 mM KNO3 or 5 mM KCl as control for 2 hours. Whole roots were cut from seedlings and frozen on liquid Nitrogen. Total RNA was extracted using the TriZol reagent. 3 independent biological replicates were performed.
2013-03-31 | E-GEOD-43011 | biostudies-arrayexpress
Project description:Auxin is a key phytohormone regulating central processes in plants that include embryo development, lateral root growth and flower maturation among others. Auxin is sensed by a set of F-Box proteins of the TIR1/AFB3 family triggering auxin dependent responses by a pathway that involves an interplay between the Aux/IAA transcription repressors and the ARF transcription factors. We have previously shown that the AFB3 auxin receptor has a specific role in coordinating primary and lateral root growth to external and internal nitrate availability (Vidal et al., 2010). In this work, we used an integrated genomics, bioinformatics and molecular genetics approach to dissect regulatory networks acting downstream AFB3 that are activated by a transient nitrate treatment in Arabidopsis roots. Our systems approach unraveled key components of the AFB3 regulatory network leading to changes in lateral root growth in response to nitrate.
2012-05-01 | GSE35544 | GEO
Project description:Plants modulate the efficiency of root nitrogen (N) acquisition in response to shoot N demand. However, molecular components directly involved in this shoot-to-root communication remain to be identified. Here, we show that phloem-mobile CEPD-like 2 (CEPDL2) polypeptide is upregulated in the leaf vasculature in response to decreased shoot N status and, after translocation to the roots, promotes high-affinity uptake and root-to-shoot transport of nitrate by activating nitrate transporter genes such as NRT2.1, NRT3.1 and NRT1.5. Loss of CEPDL2 decreases nitrate uptake and root-to-shoot transport activity in roots, leading to a reduction in shoot nitrate content and plant biomass. CEPDL2 contributes to N acquisition cooperatively with CEPD1 and CEPD2 that mediate root N status, and their complete loss severely impairs N homeostasis in plants. Reciprocal grafting analysis provided conclusive evidence that the shoot CEPDL2/CEPD genotype defines the root high-affinity uptake activity of nitrate. Our results indicate that plants integrate shoot N status and root N status in leaves and systemically regulate the efficiency of root N acquisition.
2020-02-10 | GSE140834 | GEO
Project description:Plants uptake nitrogen (N) from the soil mainly in the form of nitrate. However, nitrate is often distributed heterogeneously in natural soil. Plants, therefore, have a systemic long-distance signaling mechanism by which N-starvation on one side of the root leads to a compensatory N uptake on the other N-rich side. This systemic N acquisition response is triggered by a root-to-shoot mobile peptide hormone, C-terminally Encoded Peptide (CEP), originating from the N-starved roots, but the molecular nature of the descending shoot-to-root signal remains elusive. Here, we show that phloem-specific polypeptides that are induced in leaves upon perception of root-derived CEP act as descending long-distance mobile signals translocated to each root. These shoot-derived polypeptides, which we named CEP Downstream 1 (CEPD1) and CEPD2, upregulate the expression of the nitrate transporter gene NRT2.1 in roots specifically when nitrate is present in the rhizosphere. Arabidopsis plants deficient in this pathway show impaired systemic N-acquisition response accompanied with N-deficiency symptoms. These fundamental mechanistic insights should provide a conceptual framework for understanding systemic nutrient acquisition responses in plants. We prepared total RNA from vascular tissues of wild type, CEP1-treated wild type, and cepr1-1 mutant, and used a microarray analysis to identify genes specifically induced by CEP1.
2017-04-06 | GSE94161 | GEO
Project description:Nitrate transporter NRT2.1, which plays a central role in high-affinity nitrate uptake in roots, is activated at the post-translational level in response to nitrogen (N) starvation. However, critical enzymes required for post-translational activation of NRT2.1 remain to be identified. Here, we show that a type 2C protein phosphatase, designated CEPD-induced phosphatase (CEPH), activates high-affinity nitrate uptake by directly dephosphorylating S501 of NRT2.1, a residue that functions as a negative phospho-switch. CEPH is predominantly expressed in epidermal and cortex cells in roots and up-regulated by N starvation via a CEPDL2/CEPD1/2-mediated long-distance signaling from shoots. Loss of CEPH leads to a marked decrease in high-affinity nitrate uptake, tissue nitrate content, and plant biomass. Collectively, our results identify CEPH as a crucial enzyme in N starvation-dependent activation of NRT2.1, providing molecular and mechanistic insights into how plants regulate high-affinity nitrate uptake at the post-translational level in response to the N environment. We prepared total RNA from roots of wild type, CEPD1ox, CEPD2ox and CEPDL2ox plants grown on N-replete vertical plates for 14 d, and used a microarray analysis to identify genes specifically induced by CEPD family peptides.
2020-11-06 | GSE160649 | GEO
Project description:Nitrate transporter NRT2.1, which plays a central role in high-affinity nitrate uptake in roots, is activated at the post-translational level in response to nitrogen (N) starvation. However, critical enzymes required for post-translational activation of NRT2.1 remain to be identified. Here, we show that a type 2C protein phosphatase, designated CEPD-induced phosphatase (CEPH), activates high-affinity nitrate uptake by directly dephosphorylating S501 of NRT2.1, a residue that functions as a negative phospho-switch. CEPH is predominantly expressed in epidermal and cortex cells in roots and up-regulated by N starvation via a CEPDL2/CEPD1/2-mediated long-distance signaling from shoots. Loss of CEPH leads to a marked decrease in high-affinity nitrate uptake, tissue nitrate content, and plant biomass. Collectively, our results identify CEPH as a crucial enzyme in N starvation-dependent activation of NRT2.1, providing molecular and mechanistic insights into how plants regulate high-affinity nitrate uptake at the post-translational level in response to the N environment.
2021-03-02 | PXD022343 | Pride
Project description:Nitrate and other nitrogen metabolites can act as signals that regulate global gene expression in plants. Adaptive changes in plant morphology and physiology triggered by changes in nitrate availability are partly explained by these changes in gene expression. Despite several genome-wide efforts to identify nitrate-regulated genes, no comprehensive study of the Arabidopsis root transcriptome under contrasting nitrate conditions has been carried out. In this work, we employed the Illumina high throughput sequencing technology to perform an integrated analysis of the poly-A+ enriched and the small RNA fractions of the Arabidopsis thaliana root transcriptome in response to nitrate treatments. Our sequencing strategy identified new nitrate-regulated genes including 40 genes not represented in the ATH1 Affymetrix GeneChip, a novel nitrate-responsive antisense transcript and a new nitrate responsive miRNA/TARGET module consisting of a novel microRNA, miR5640 and its target, AtPPC3. This nitrate-responsive miRNA/target module might be involved in controlling carbon flux to assimilate nitrate into amino acids, suggesting that microRNAs can have both developmental and metabolic functions in the nitrate response of Arabidopsis roots.
2013-07-01 | GSE44062 | GEO
Project description:Auxin is a key phytohormone regulating central processes in plants that include embryo development, lateral root growth and flower maturation among others. Auxin is sensed by a set of F-Box proteins of the TIR1/AFB3 family triggering auxin dependent responses by a pathway that involves an interplay between the Aux/IAA transcription repressors and the ARF transcription factors. We have previously shown that the AFB3 auxin receptor has a specific role in coordinating primary and lateral root growth to external and internal nitrate availability (Vidal et al., 2010). In this work, we used an integrated genomics, bioinformatics and molecular genetics approach to dissect regulatory networks acting downstream AFB3 that are activated by a transient nitrate treatment in Arabidopsis roots. Our systems approach unraveled key components of the AFB3 regulatory network leading to changes in lateral root growth in response to nitrate. Arabidopsis seedlings of the Ws and afb3-1 genotypes were grown on hydroponic medium containing 1X MS salts without Nitrogen, supplemented with 0.5 mM ammonium succinate as Nitrogen source and 3 mM sucrose on a Percival chamber under a photoperiod of 16 hours of light (100 μE/m2/sec) and 8 hours of dark at 22°C for 14 days. The plants were treated at the onset of the light cycle with 5 mM KNO3 or 5 mM KCl as control for 2 hours. Whole roots were cut from seedlings and frozen on liquid Nitrogen. Total RNA was extracted using the TriZol reagent. 3 independent biological replicates were performed.
2012-04-30 | E-GEOD-35544 | biostudies-arrayexpress
Project description:In lieu of strategies to escape unfavorable conditions, plants have evolved mechanisms to cope with and adapt to changes in their environment. Environment pH (pHe) is a key parameter that dictates a surfeit of conditions of critical importance for plant survival and fitness. Besides responses to altered availability of essential nutrients, changes in pHe recalibration of cytoplasmic and apoplastic pH despite constant fluctuations. To elucidate processes allowing such acclimations, we conducted a comprehensive proteomic/phosphoproteomic survey of plants subjected to transient exposure to acidic or alkaline pH, an approach that covered more than 60% of the protein-coding genes of the model plant Arabidopsis thaliana. Differentially (phospho)peptides displayed moderate concordance to previously published transcriptomic data sets, indicative of extensive post-transcriptomic regulation. This finding is corroborated by the discovery of xx so far undocumented, possibly pH-specific phospho-sites in response to alterations in pHe. Both low and high pHe altered proton-translocation across the plasma membrane. In pH 7.5 plants, transport but not assimilation of nitrogen was strongly induced, possibly to increase cytosolic H+ concentration. Mutants defective in the nitrate transporter nrt2.1 exhibited longer roots at low pH and increased density of root hairs at high pH, suggesting a moonlighting role of NRT2.1 in root growth. Only a few pH-responsive proteins were associated with the transport of iron and zinc, the availability of which is altered by pHe. Intricate phosphorylation of the ABC transporters PDR7 and PDR8 suggests pH-dependent phospho-switches in substrate specificity, tipping the balance between growth and defense. Unexpectedly, pHe provoked pronounced, changes in the leaf proteome, possibly communicated via an elaborate calcium-dependent signaling network. Moreover, we show that the TPLATE compounds EH1 and EH2 are differentially phosphorylated at multiple sites in response to pHe, indicating that the endocytic cargo protein trafficking is orchestrated by pHe.
2023-09-18 | PXD045226 | Pride
Project description:Nitrate and other nitrogen metabolites can act as signals that regulate global gene expression in plants. Adaptive changes in plant morphology and physiology triggered by changes in nitrate availability are partly explained by these changes in gene expression. Despite several genome-wide efforts to identify nitrate-regulated genes, no comprehensive study of the Arabidopsis root transcriptome under contrasting nitrate conditions has been carried out. In this work, we employed the Illumina high throughput sequencing technology to perform an integrated analysis of the poly-A+ enriched and the small RNA fractions of the Arabidopsis thaliana root transcriptome in response to nitrate treatments. Our sequencing strategy identified new nitrate-regulated genes including 40 genes not represented in the ATH1 Affymetrix GeneChip, a novel nitrate-responsive antisense transcript and a new nitrate responsive miRNA/TARGET module consisting of a novel microRNA, miR5640 and its target, AtPPC3. This nitrate-responsive miRNA/target module might be involved in controlling carbon flux to assimilate nitrate into amino acids, suggesting that microRNAs can have both developmental and metabolic functions in the nitrate response of Arabidopsis roots. Arabidopsis thaliana wild-type Col-0 plants were grown in hydroponic nitrate-free medium with 0.5 mM ammonium succinate as the only N-source for two weeks and were treated with 5 mM KNO3, or 5 mM KCl as control, for 2 hours. Total RNA from two independent sets of plants (biological replicates) was extracted from roots, and poly-A+ enriched and sRNA fractions were used to construct libraries for Illumina sequencing.
2013-07-01 | E-GEOD-44062 | biostudies-arrayexpress