Two aspects of light are very important for plant development: the length of the light phase or photoperiod and the quality of incoming light. Photoperiod detection allows plants to anticipate the arrival of the next season, whereas light quality, mainly the red to far-red ratio (R:FR), is an early signal of competition by neighbouring plants. phyB represses flowering by antagonising CO at the transcriptional and post-translational levels. A low R:FR decreases active phyB and consequently increases active CO, which in turn activates the expression of FT, the plant florigen. Other phytochromes like phyD and phyE seem to have redundant roles with phyB. PFT1, the MED25 subunit of the plant Mediator complex, has been proposed to act in the light-quality pathway that regulates flowering time downstream of phyB. However, whether PFT1 signals through CO and its specific mechanism are unclear. Here we show that CO-dependent and -independent mechanisms operate downstream of phyB, phyD and phyE to promote flowering, and that PFT1 is equally able to promote flowering by modulating both CO-dependent and -independent pathways. Our data are consistent with the role of PFT1 as an activator of CO transcription, and also of FT transcription, in a CO-independent manner. Our transcriptome analysis is also consistent with CO and FT genes being the most important flowering targets of PFT1. Furthermore, comparison of the pft1 transcriptome with transcriptomes after fungal and herbivore attack strongly suggests that PFT1 acts as a hub, integrating a variety of interdependent environmental stimuli, including light quality and jasmonic acid-dependent defences.
PFT1, the MED25 subunit of the plant Mediator complex, promotes flowering through CONSTANS dependent and independent mechanisms in Arabidopsis.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
LNK genes integrate light and clock signaling networks at the core of the Arabidopsis oscillator.
Specimen part, Treatment, Time
View SamplesLight pulses at the end of the day or night be able to control the phase of the circadian clock. Pulses in the middle of the night has not effect on the circadian oscilations.
LNK genes integrate light and clock signaling networks at the core of the Arabidopsis oscillator.
Specimen part, Treatment, Time
View SamplesPlants regulate their time to flowering by gathering information from the environment. Photoperiod and temperature are among the most important environmental variables. Suboptimal, but not near-freezing, temperatures regulate flowering through the thermosensory pathway, which overlaps with the autonomous pathway. Here we show that ambient temperature regulates flowering by two genetically distinguishable pathways, one that requires TFL1 and another that requires ELF3. The delay in flowering time observed at lower temperatures was partially suppressed in single elf3 and tfl1 mutants, whereas double elf3 tfl1 mutants were insensitive to temperature. tfl1 mutations abolished the temperature response in cryptochrome mutants that are deficient in photoperiod perception, but not in phyB mutants that have a constitutive photoperiodic response. Contrary to tfl1, elf3 mutations were able to suppress the temperature response in phyB mutants, but not in cryptochrome mutants. The gene expression profile revealed that the tfl1 and elf3 effects are due to the activation of different sets of genes and identified CCA1 and SOC1/AGL20 as being important cross talk points. Finally, genome-wide gene expression analysis strongly suggests a general and complementary role for ELF3 and TFL1 in temperature signalling.
A complementary role for ELF3 and TFL1 in the regulation of flowering time by ambient temperature.
No sample metadata fields
View SamplesFlowering time is a complex trait regulated by many genes that are integrated in different genetic pathways. Different genetic screenings carried out during the past decades have revealed an intrincated genetic regulatory network governing this trait. Efforts aimed at improving our understanding of how such genetic pathways respond to genetic and enviromental cues are needed.
The arabidopsis DNA polymerase δ has a role in the deposition of transcriptionally active epigenetic marks, development and flowering.
Age, Specimen part
View SamplesAnalysis of gene-expression profiles with microarrays can be very useful to dissect specific responses and to characterize with a global view, new elements for improving the diagnosis, treatment and understanding of allergic diseases. We have used this approach for studying the olive pollen response, taking advantage our previous results of T-cell epitope mapping on Ole e 1 molecule (the major allergen from olive pollen) in order to analyze the stimuli influence on the gene-expression of olive pollen allergic patients. Peripheral blood mononuclear cells (PBMCs) from 6 healthy controls and 6 allergic subjects were stimulated 24 hours with olive pollen stimuli: Ole e 1 molecule and two Ole e 1 peptides previously defined as P2+3 (aa10-31), mainly recognized by non-allergic subjects (possible immunoregulatory epitope) and P10+12+13 (aa90-130), immunodominant T-cell epitope. RNA extracted from basal and stimulated PBMCs was analyzed by HuGeU133 plus 2.0 GeneChip, Affymetrix (38.500genes). After assessment of data quality by standard quality checks and principal components analysis (PCA), differential gene-expression by experimental conditions was performed by multiple testing, using microarrays specific software. Differences in functional analysis were performed by KEGG, for pathways and Gene-Ontology for biological process. The results of gene-expression by PCA showed differential clusters that correlated with the experimental conditions from samples of allergic patients. Analysis of differential gene-expression by multiple testing, and functional analysis by KEGG and Gene-Ontology revealed differential genes and pathways among the 4 experimental conditions.
Therapeutic targets for olive pollen allergy defined by gene markers modulated by Ole e 1-derived peptides.
Specimen part, Disease
View SamplesAnalysis of gene-expression profiles by microarrays can be very useful to characterize new potential candidate genes, key regulatory networks, and to define phenotypes or molecular signatures to improve the diagnosis or classification of the disease. We have used this approach in the study of one of the major causes of allergic diseases in Mediterranean countries, the olive pollen response, in order to find differential molecular markers among five clinical groups, Non-allergic, Asymptomatic, Allergic but not to olive pollen, Non-treated, olive pollen allergic patients and Olive pollen allergic patients (under specific-immunotherapy). The results of gene-expression by principal components analysis (PCA) clearly showed five clusters of samples that correlated with the five clinical groups. Analysis of differential gene-expression by multiple testing, and functional analysis by KEGG and Gene-Ontology revealed differential genes and pathways among the 5 clinical groups.
Differential gene-expression analysis defines a molecular pattern related to olive pollen allergy.
No sample metadata fields
View SamplesMice selected for high and low acute inflammation were tested for pristane induced arthritis, showing to be susceptible and resistant, respectively.
Pristane-induced arthritis loci interact with the Slc11a1 gene to determine susceptibility in mice selected for high inflammation.
Sex, Age, Specimen part
View SamplesCerebral listeriosis is characterized by neuronal apoptosis and microglial cell activation, but little is known about the bacterial virulence factors involved in this process and how bacterial dissemination is controlled. Here, we show that the cellular target of Listeria monocytogenes (LM) in murine hippocampal cultures is microglia rather than neurons or other glial cells, which are rarely infected. This in vitro model served to demonstrate that infected microglial cells release a soluble factor to the medium responsible for neuronal apoptosis. We investigated the production of this factor in a well-established murine microglia cell model BV2 cells, and compared with J-774 macrophage cells after infection with different LM bacterial mutants. Our purpose was to study in both cell types parameters such as the listericidal capacities, pro-inflammatory cytokines released, and bacterial factors involved in the intracellular cycle.
No associated publication
Specimen part, Cell line
View SamplesThis study focus a comparative toxicogenomic analysis of the effects of four herbicides (alachlor, ALA, S-metolachlor, S-MET, diuron, DIU, and MCPA-methyl ester, MCPA-ME), one insecticide (carbofuran, CAB), and one fungicide (pyrimethanil, PYR), in the model yeast Saccharomyces cerevisiae, to predict potential cytotoxic effects of these xenobiotics while providing mechanistic clues possibly relevant for experimentally less accessible non-target eukaryotes. The six model pesticides selected have been used worldwide in agricultural activities, at the present time or in the past, and have different modes of action on their target-organisms. Moreover, some of them are currently in Annex 1 of EC Directive 1107/2009 (repealing 91/414), that is they are in use in the EU, but having some ecotoxicological concerns (e.g. S-MET, PYR, MCPA-ME), others have their use restricted and/or are priority substances under the Water Framework Directive (e.g. ALA, DIU), and one was banned (e.g. CAB).
Comparative analysis of transcriptomic responses to sub-lethal levels of six environmentally relevant pesticides in Saccharomyces cerevisiae.
Treatment
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