Tissue-specific transcriptome analysis in nodules of Lotus japonicus
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ABSTRACT:
ORGANISM(S): Lotus japonicus
PROVIDER: GSE34753 | GEO | 2011/12/29
SECONDARY ACCESSION(S): PRJNA150369
REPOSITORIES: GEO
Similar Datasets
Project description:Legume plants can establish symbiotic nitrogen fixation (SNF) with rhizobia mostly in root nodules, where rhizobia-infected cells are accompanied with uninfected cells in a mosaic pattern. Inside the mature nodules of legume, carbon and nitrogen nutrients between host plant cells and their resident bacteria are actively exchanged. To elucidate the metabolite dynamics relevant for SNF in nodules, three cell-types from nodule tissues of a model legume, Lotus japonicus, were isolated using laser microdissesction, and transcriptome analysis was done by an oligoarray with 60-mer length representing 21,495 genes. In our cell-type-specific profiling, many genes were identified as being expressed in nodules with spatial-specific manners. Among them, genes coding for metabolic enzymes were classified according to their function, and detailed data analysis figured out that secondary metabolic pathway was highly activated in nodule cortex. In particular, a number of metabolic genes for phenyl propanoid pathway were found as highly expressed genes accompanied with those encoding putative transporters of secondary metabolites. These data suggest the involvement of novel physiological function of phenylpropanoids in SNF. Gene expression in three different cell-types of Lotus japonicus nodule was measured. Three independent experiments were performed at each cell-types.
2011-12-29 | E-GEOD-34753 | biostudies-arrayexpress
Project description:During the legume-rhizobium symbiosis, free-living soil bacteria known as rhizobia trigger the formation of root nodules. The rhizobia infect these organs and adopt an intracellular lifestyle within the symbiotic nodule cells where they become nitrogen-fixing bacteroids. Several legume lineages enforce their symbionts into an extreme cellular differentiation, comprising cell enlargement and genome endoreduplication. The antimicrobial peptide transporter BclA is a major determinant of this differentiation process in Bradyrhizobium sp. ORS285, a symbiont of Aeschynomene spp.. In the absence of BclA, Bradyrhizobium sp. ORS285 proceeds until the intracellular infection of nodule cells but the bacteria cannot differentiate into enlarged polyploid bacteroids and fix nitrogen. The nodule bacteria of the bclA mutant constitute thus an intermediate stage between the free-living soil bacteria and the intracellular nitrogen-fixing bacteroids. Metabolomics on whole nodules of Aeschynomene afraspera and Aeschynomene indica infected with the ORS285 wild type or the bclA mutant revealed 47 metabolites that differentially accumulated concomitantly with bacteroid differentiation. Bacterial transcriptome analysis of these nodules discriminated nodule-induced genes that are specific to differentiated and nitrogen-fixing bacteroids and others that are activated in the host microenvironment irrespective of bacterial differentiation and nitrogen fixation. These analyses demonstrated that the intracellular settling of the rhizobia in the symbiotic nodule cells is accompanied with a first transcriptome switch involving several hundreds of upregulated and downregulated genes and a second switch accompanying the bacteroid differentiation, involving less genes but that are expressed to extremely elevated levels. The transcriptomes further highlighted the dynamics of oxygen and redox regulation of gene expression during nodule formation and we discovered that bclA represses the expression of non-ribosomal peptide synthetase gene clusters suggesting a non-symbiotic function of BclA. Together, our data uncover the metabolic and gene expression changes that accompany the transition from intracellular bacteria into differentiated nitrogen-fixing bacteroids.
2019-06-01 | GSE126971 | GEO
Project description:Legumes establish endosymbiotic associations with nitrogen-fixing rhizobia, which they host inside root nodules. Here, specific physiological and morphological adaptations, such as the production of oxygen-binding leghemoglobin proteins and the formation of an oxygen diffusion barrier in the nodule periphery, are essential to protect the oxygen-labile bacterial nitrogenase enzyme. The molecular basis of the latter process remains elusive, as the identification of required genes is limited by the epistatic effect of nodule organogenesis over nodule infection and rhizobia accommodation. We overcame this by exploring the phenotypic diversity of Lotus japonicus accessions that uncouple nodule organogenesis from nodule infection when inoculated with a sub-compatible Rhizobium strain. Using comparative transcriptomics, we identified genes with functions associated with oxygen homeostasis and deposition of lipid polyesters on cell walls to be specifically upregulated in infected compared to uninfected nodules. As such hydrophobic modifications on cell walls are pivotal for creating diffusion barriers like the root endodermis, we focused on two Fatty acyl-CoA reductase genes that were specifically activated in the nodule or in the root endodermis. Mutant lines in a Fatty acyl-CoA reductase gene expressed exclusively in the nodule endodermis showed had decreased suberization of this cell layer and increased nodule permeability compared to wild type plants. Oxygen concentrations were significantly increased in the inner cortex of mutant nodules, which correlated with reduced nitrogen fixation rates, and impaired shoot growth. These results provide the first genetic evidence for the formation of the nodule oxygen diffusion barrier, a key adaptation enabling nitrogen fixation in legume nodules.
2022-11-01 | GSE216502 | GEO
Project description:Nitrogen assimilation in plants is a tightly regulated process that integrates developmental and environmental signals. The legume-rhizobial symbiosis results in the formation of a specialized organ called root nodule, where the rhizobia fixes atmospheric nitrogen into ammonia. Ammonia is assimilated by the plant enzyme glutamine synthetase, which is specifically inhibited by PPT. The expression of key genes related to the regulation of root nodule metabolism will likely be affected by glutamine synthetase inhibition. We used microarrays to detail the global programme of gene expression in response to Glutamine synthetase inhibition in root nodules and identified genes differentially expressed over a time course.
2012-05-09 | GSE34155 | GEO
Project description:Nitrogen assimilation in plants is a tightly regulated process that integrates developmental and environmental signals. The legume-rhizobial symbiosis results in the formation of a specialized organ called root nodule, where the rhizobia fixes atmospheric nitrogen into ammonia. Ammonia is assimilated by the plant enzyme glutamine synthetase, which is specifically inhibited by PPT. The expression of key genes related to the regulation of root nodule metabolism will likely be affected by glutamine synthetase inhibition. We used microarrays to detail the global programme of gene expression in response to Glutamine synthetase inhibition in root nodules and identified genes differentially expressed over a time course. Medicago truncatula nodulated plants (20 days post inoculation) were treated with 0.25 mM of PPT. Root nodules were harvested at 4, 8 and 24 hours after PPT application. As a control, root nodules collected just before PPT application were used (PPT 0h). Three biological replicates consisting of pools of root nodules harvested from five distinct plants were used for RNA extraction and hybridization on Affymetrix GeneChips.
2012-05-08 | E-GEOD-34155 | biostudies-arrayexpress
Project description:affy_med_2011_06 - affy_med_2011_06 - Legume plants establish a symbiotic interaction with soil bacteria called rhizobia. A complex molecular dialogue between the two partners is necessary for the successful infection and organogenesis processes that will ultimately result in the formation of a nitrogen fixing nodule. During a M. truncatula Tnt1 mutant screen, a new class of symbiotic mutant called noot (nodule root) was identified. This original single recessive mutant develops a root in apical position of nodules that are colonized by bacteria and functional for nitrogen fixation. This conversion suggests that the legume nodule morphogenetic pathway may be derived from a root program. We cloned the NOOT gene and showed that it corresponds to Pisum sativum COCH (Ferguson and Reid, 2005, Plant Cell Physiol 46, 1583-1589). The goal of this project is to compare the transcriptomes from wild type nodules and roots to the noot nodule one. This will allow us to unravel the similarity and differences between the wild type and mutant nodule transcriptomes but also to know which developmental pathway is under the control of the NOOT gene. --Seeds of the WT and noot mutant lines (two mutant alleles: Tnk507 and NF2717) were surface sterilized and placed at 4°C for three days on a minimal BNM medium square plate (12cm X 12cm). Seeds were germinated at room temperature and 10 seeds were placed in a row on nitrogen poor (BNM) plate. Seedlings were inoculated using Sinorhizobium meliloti Rm41 for nodule production. Some WT plants were not infected by the bacteria in order to collect roots. Nodules and roots were harvested 18 to 21 days post inoculation. Each experimental repetition (3 WT nodules, 3 WT roots and 2 mutant nodules of each allele) was harvested at a separated day. RNA preparations were done using a Quiagen Kit. 10 arrays - Medicago; gene knock out,organ comparison
2012-05-31 | E-GEOD-36558 | biostudies-arrayexpress
Project description:affy_med_2011_06 - affy_med_2011_06 - Legume plants establish a symbiotic interaction with soil bacteria called rhizobia. A complex molecular dialogue between the two partners is necessary for the successful infection and organogenesis processes that will ultimately result in the formation of a nitrogen fixing nodule. During a M. truncatula Tnt1 mutant screen, a new class of symbiotic mutant called noot (nodule root) was identified. This original single recessive mutant develops a root in apical position of nodules that are colonized by bacteria and functional for nitrogen fixation. This conversion suggests that the legume nodule morphogenetic pathway may be derived from a root program. We cloned the NOOT gene and showed that it corresponds to Pisum sativum COCH (Ferguson and Reid, 2005, Plant Cell Physiol 46, 1583-1589). The goal of this project is to compare the transcriptomes from wild type nodules and roots to the noot nodule one. This will allow us to unravel the similarity and differences between the wild type and mutant nodule transcriptomes but also to know which developmental pathway is under the control of the NOOT gene. --Seeds of the WT and noot mutant lines (two mutant alleles: Tnk507 and NF2717) were surface sterilized and placed at 4°C for three days on a minimal BNM medium square plate (12cm X 12cm). Seeds were germinated at room temperature and 10 seeds were placed in a row on nitrogen poor (BNM) plate. Seedlings were inoculated using Sinorhizobium meliloti Rm41 for nodule production. Some WT plants were not infected by the bacteria in order to collect roots. Nodules and roots were harvested 18 to 21 days post inoculation. Each experimental repetition (3 WT nodules, 3 WT roots and 2 mutant nodules of each allele) was harvested at a separated day. RNA preparations were done using a Quiagen Kit.
2012-06-01 | GSE36558 | GEO
Project description:Legume plants form symbiotic relationships with diazotrophic bacteria called rhizobia. During such symbiosis, plants provide bacteria with preferred carbon sources such as malate and succinate in return for essential reduced nitrogen. Compatible interactions result in a series of plant root modifications that eventually result in nodule formation. Bacteria living in the nodule cells fix nitrogen via the nitrogenase enzyme complex. Interestingly, as in plant-pathogen interactions, incompatibility in legume-rhizobia associations is also regulated in a genotype-specific manner. For example, the dominant Rj2 gene is presumed to help exclude poor nitrogen-fixing or less-beneficial rhizobia such as B. japonicum USDA122 (U122). The process likely involves recognition of bacterial effectors by host receptor proteins similar to the perception of pathogenic microbes. Our results show that genetic exclusion of incompatible rhizobia in the root requires conserved molecular components of the plant immune response pathway and results in the induction of systemic signaling in the distal tissue. To better understand the mechanism underlying incompatible rhizobia-induced systemic signaling, we compared the transcriptional changes in the foliar tissue of Rj2 plants inoculated with compatible or incompatible rhizobia strains, using RNA-Seq analysis.
2019-10-24 | GSE139303 | GEO
Project description:Metabolomics and transcriptomics of Bradyrhizobium diazoefficiens-induced root nodules Bradyrhizobium diazoefficiens is a nitrogen-fixing endosymbiont, which can grow inside root-nodule cells of the agriculturally important soybean and other host plants. Our previous studies described B. diazoefficiens host-specific global expression changes occurring during legume infection at the transcript and protein level. In order to further characterize nodule metabolism, we here determine by flow injection -time of flight mass spectrometry analysis the metabolome of i) nodules and roots from four different B. diazoefficiens host plants, ii) soybean nodules harvested at different time points during nodule development, and iii) soybean nodules infected by two strains mutated in key genes for nitrogen fixation, respectively. Ribose (soybean), tartaric acid (mungbean), hydroxybutanoyloxybutanoate (siratro) and catechol (cowpea) were among the metabolites found to be specifically elevated in one of the respective host plants. While the level of C4-dicarboxylic acids decreased during soybean nodule development, we observed an accumulation of trehalose-phosphate at 21 days post infection (dpi). Moreover, nodules from non-nitrogen-fixing bacteroids (nifA and nifH mutants) showed specific metabolic alterations; these were also supported by transcriptomics data that was generated for the two mutant strains and were helpful to separate for some examples the respective bacterial and plant contributions to the metabolic profile. The alterations included signs of nitrogen limitation in both mutants, and an increased level of a phytoalexin in nodules induced by the nifA mutant, suggesting that the tissue of these nodules exhibits defense and stress reactions.
2016-11-28 | GSE79811 | GEO
Project description:Medicago truncatula engages in root nodule symbiosis by developing a de novo plant organ (known as nodule) in its roots in response to the infection by rhizobia. These nodules are de novo plant organs that provide an optimal environment for the rhizobia to fix nitrogen in exchange for photosynthates. The establishment of root nodule symbioses (RNS) requires the coordination of two distinct processes: bacterial infection and nodule organogenesis. In this study we used single-cell RNA-seq to investigate the first hours of the establishment of the root nodule symbiosis aiming to identify the transcriptional mechanisms governing this process.
2024-01-17 | GSE224539 | GEO