Project description:CHL1 functions as a nitrate sensor and also is one of major nitrate transporters responsible for nitrate responses and uptake. ANI is a protein phosphatase particiates in temporal nitrate response, its influence was analyzed in a global transcriptome study using Affymetrix ATH1 array. Two biological replicates of 10-day-old Arabidopsis root tissue from wild-type and ani1 plants were performed to explore differences in gene expression between the wild-type and ani1 mutants exposed to 200 μM nitrate for 0h (T0), 0.5h (T0.5), or 16h (T16) using Affymetrix ATH1 microarray.
Project description:CHL1 is one of major nitrate transporters responsible for nitrate uptake and some studies suggest that it may be also play a role in regulating the nitrate response, its influence was analyzed in a global transcriptome study using Affymetrix ATH1 array. Keywords: Time course
Project description:CHL1 is one of major nitrate transporters responsible for nitrate uptake and some studies suggest that it may be also play a role in regulating the nitrate response, its influence was analyzed in a global transcriptome study using Affymetrix ATH1 array. Experiment Overall Design: Three biological replicates of 10-day-old Arabidopsis root tissue from wild-type and chl1-5 plants were performed to explore differences in gene expression between the wild-type and chl1-5 mutants exposed to 25 mM nitrate for 0h (T0) or 0.5h (T0.5) using Affymetrix ATH1 microarray.
Project description:NRT1.1 is a nitrate transceptor involved in many nitrate responses including the regulation of gene expression through (i) the Primary Nitrate Response (PNR) and (ii) the regulation the NRT2.1 gene under continuous high NH4NO3 conditions. Phosphorylation of NRT1.1’s T101 residue is involved in the modulation of the PNR whereas nitrate transport by NRT1.1 is not. Here we used various NRT1.1 point mutants to study the impact of NRT1.1 on the whole transcriptome under high NH4NO3 supply. Col is the WT control, chl1-5 and chl1-12 are KO mutants, chl1-9 is defective in nitrate transport but not in PNR induction, T101D and T101A mimick the phosphorylated and not phosphorylated forms of NRT1.1 respectively.
Project description:NRT1.1 is a nitrate transceptor involved in many nitrate responses including the regulation of gene expression through (i) the Primary Nitrate Response (PNR) and (ii) the regulation the NRT2.1 gene under continuous high NH4NO3 conditions. Phosphorylation of NRT1.1’s T101 residue is involved in the modulation of the PNR whereas nitrate transport by NRT1.1 is not. Here we used various NRT1.1 point mutants to study the impact of NRT1.1 on the whole transcriptome under high NH4NO3 supply. Col is the WT control, chl1-5 and chl1-12 are KO mutants, chl1-9 is defective in nitrate transport but not in PNR induction, T101D and T101A mimick the phosphorylated and not phosphorylated forms of NRT1.1 respectively. This work studies the impact of various NRT1.1 mutations on the transcriptome under 10mM NH4N03 supply.
Project description:As multicellular organisms, plants must integrate responses to environmental cues across different cell types and also over time. Nitrate is the major source of available Nitrogen for plants, and a limiting factor for plant growth and productivity. Plant root s are highly impacted by nitrate availability, modifying their architecture to optimize nitrate uptake from soils. In order to understand how this functional response is dynamically orchestrated across different cell types of the root, space and time must be addressed within the same experimental setup. We performed a transcriptomic analysis in five major root cell types of Arabidopsis plants in response to nitrate treatments considering short and long time exposure to this macronutrient. We found nitrate treatment triggers a dynamic reprogramming of root cell gene expression that follows a spatial pattern over time consistent with an early regulation of nitrate transport and assimilation in external layers of the root and a later regulation of hormonal and developmental processes in more internal layers of the root.
Project description:The airway epithelium represents a critical component of the human lung that helps orchestrate defences against respiratory tract viral infections, which are responsible for more than 2.5 million deaths/year globally. Innate immune activities of the airway epithelium rely Toll-like receptors (TLRs), nucleotide binding and leucine-rich-repeat pyrin domain containing (NLRP) receptors, and cytosolic nucleic acid sensors. ATP Binding Cassette (ABC) transporters are ubiquitous across all three domains of life – Archaea, Bacteria, and Eukarya – and expressed in the human airway epithelium. ABCF1, a unique ABC family member that lacks a transmembrane domain, has been defined as a cytosolic nucleic acid sensor that regulates CXCL10, interferon-b expression, and downstream type I interferon responses. We tested the hypothesis that ABCF1 functions as a dsDNA nucleic acid sensor in human airway epithelial cells important in regulating antiviral responses.
Project description:Nitrate is the limiting nitrogen nutrient enabling photosynthetic plants to support the conversion of inorganic elements to organic biomass, which sustains all lives. Plants evolved multifaceted nitrate responses to modulate global gene expression, metabolism and developmental programs. However, primary nitrate signaling mechanisms remained elusive. Using an ultrasensitive Ca2+ biosensor, unique nitrate-induced Ca2+ signaling was illuminated in Arabidopsis cells and plants. Integrative functional genomic screens, chemical genetics, genome-wide transcript sequencing, and analyses of nitrate-associated traits uncovered the surprising roles of Ca2+ sensor protein kinases (CPKs) in orchestrating diverse primary and long-term nitrate responses. Nitrate specifies CPK signaling to reprogram transcriptome and govern N-assimilation, metabolism, transport, hormones, shoot growth, and root system architecture. CPKs may be targeted to enhance nitrogen-use-efficiency, reduce fertilizer demands, and alleviate ecosystem pollution.
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.
Project description:The genomic response to low levels of nitrate was studied in Arabidopsis using the Affymetrix ATH1 chip containing more than 22,500 probe sets. Arabidopsis plants were grown hydroponically in sterile liquid culture on ammonium as the sole source of nitrogen for 10 d, then treated with 250 um nitrate for 20 min. The response to nitrate was much stronger in roots (1,176 genes showing increased or decreased mRNA levels) than in shoots (183 responding genes). In addition to known nitrate-responsive genes (e.g. those encoding nitrate transporters, nitrate reductase, nitrite reductase, ferredoxin reductase, and enzymes in the pentose phosphate pathway), genes encoding novel metabolic and potential regulatory proteins were found. These genes encode enzymes in glycolysis (glucose-6-phosphate isomerase and phosphoglycerate mutase), in trehalose-6-P metabolism (trehalose-6-P synthase and trehalose-6-P phosphatase), in iron transport/metabolism (nicotianamine synthase), and in sulfate uptake/reduction. In many cases, only a few select genes out of several in small gene families were induced by nitrate. These results show that the effect of nitrate on gene expression is substantial (affecting almost 10% of the genes with detectable mRNA levels) yet selective and affects many genes involved in carbon and nutrient metabolism. Keywords: Expression profilling by array 8 samples were used in this experiment