Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Gene expression data from phosphinothricin (PPT) treated Medicago truncatula root nodules

ABSTRACT: 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.

ORGANISM(S): Medicago truncatula

SUBMITTER: Helena Carvalho

PROVIDER: E-GEOD-34155 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Publications

Inhibition of glutamine synthetase by phosphinothricin leads to transcriptome reprograming in root nodules of Medicago truncatula.

Seabra Ana R AR Pereira Patrícia A PA Becker Jörg D JD Carvalho Helena G HG

Molecular plant-microbe interactions : MPMI 20120701 7

Glutamine synthetase (GS) is a vital enzyme for the assimilation of ammonia into amino acids in higher plants. In legumes, GS plays a crucial role in the assimilation of the ammonium released by nitrogen-fixing bacteria in root nodules, constituting an important metabolic knob controlling the nitrogen (N) assimilatory pathways. To identify new regulators of nodule metabolism, we profiled the transcriptome of Medicago truncatula nodules impaired in N assimilation by specifically inhibiting GS act ...[more]

PMID: 22414438

Similar Datasets

Project description:Biological nitrogen fixation (BNF) is a primary input of nitrogen to natural and agricultural systems globally. BNF is a temperature-dependant enzymatic process and can be conducted by microbes (including Rhizobia) hosted symbiotically in root nodules of some plants. Heat shock proteins (Hsps) have been implicated in the process of acquiring thermotolerance or acclimating to elevated temperature, as they play a vital role in maintaining cell integrity and homeostasis during heat stress. Although the BNF response to temperature may crucially impact future ecosystem productivity in the face of global climate change, little is known about Hsp expression in nodules of N-fixing non-agricultural species, such as tropical N-fixing trees in the Fabaceae family. This project aimed to characterize small (15-20kDa) Hsp (sHsp) expression in nodule tissue to examine the biochemical mechanisms of heat response in these tissues. To first identify Hsps in nodule tissues, Vachellia farnesiana and Acacia confusa nodules were excised, heat shock was induced, and protein content was isolated via chemical treatment before separation of protein species and analysis with SDS-PAGE. Two polyacrylamide gels yielded bands in the 15-20 kDa region that displayed differential Coomassie staining, which were sent for further characterization by HPLC-MS analysis for protein sequencing. Ten rhizobial sHsps were detected in these samples in addition to seven Acacia sHsps when compared independently to reference rhizobial and plant proteome databases. In an attempt quantify relative expression of Hsps in nodule and root tissue, we performed western blot experiments using Anti-Hsp20 antibodies raised against human and mouse Hsp proteins, with anti-beta actin loading control. While nonuniform beta-actin expression across tissue types (A. confusa nodules versus root control) prevented quantitative analysis, the experiments validated that Hsp20s are expressed in Acacia nodules as well as in root tissue. These experiments could provide a foundation for future studies that aim to determine variation in responses to key stressors predicted to increase with global climate change and help determine the implications of warming across the tropics and beyond.

Project description:Transcriptional profiling of hop samples throughout in vitro culture on medium with sucrose and hormones IAA and BAP Study of gene expression involved in stress response during in vitro culture and in organogenic nodule formation Hop (Humulus lupulus L.) is an economically important plant forming organogenic nodules which can be used for genetic transformation and micropropagation. We are interested in the mechanisms underlying reprogramming of cells through stress and hormone treatments. To investigate the spatio-temporal sequence of events that underlies competence acquisition for organogenesis three main stages were selected: (i) internodes at the time of excision from the parent plant (T0); (ii) internodes grown for 15 days on culture medium in which several prenodular structures are formed inside the calli (T15d); and (iii) nodule forming tissue after 28 days of culture (T28d). Additionally a control was included corresponding to 28 days of culture without hormones, lacking nodule formation and plantlet regeneration abilities, in order to identify genes specifically involved in morphogenesis (T28dWH). Organogenic nodule formation is a morphogenic process that shares features with somatic embryogenesis though in the former no shoot/root pole is established and plantlet regeneration can occur from different peripheral regions of nodules. Previous studies have shown that the organogenesis-determining period (when cells are determined to form nodules) occurs in between 15 and 25 days of culture corresponding to prenodular and first nodular stages. When nodules are fully developed they are surrounded by layers of elongated, highly vacuolated cells that may degenerate when nodules start differentiating plantlets. Plantlet regeneration from organogenic nodules can be observed after 45 days of culture. However, organogenic nodules after 28 days of culture are already determined to undergo plantlet regeneration, since they no longer require exogenous supply of hormones. Explants cultured in medium without hormones can develop incipient prenodular structures with vascular tissue but not nodules, thus lacking morphogenic potential. Keywords: Plant development, Time course 3 time points: 3 Biological replicates and 1 technical replicate (1 dye-swap). 1 control at beginning of culture and 1 control wihout hormones. One replicate per array. Each clone printed twice in the same sub-grid

Dataset Information

Gene expression data from phosphinothricin (PPT) treated Medicago truncatula root nodules

Publications

Inhibition of glutamine synthetase by phosphinothricin leads to transcriptome reprograming in root nodules of Medicago truncatula.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets