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E-MEXP-2358
Arabidopsis thaliana
6 Downloadable Samples
Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Transcript profiling of transgenic Arabidopsis thaliana seedlings constitutively overexpressing UGT74E2 (35S::UGT74E2).
Publication Title
Perturbation of indole-3-butyric acid homeostasis by the UDP-glucosyltransferase UGT74E2 modulates Arabidopsis architecture and water stress tolerance.
Sample Metadata Fields
Specimen part
View Samples- Arabidopsis thaliana
- 30 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Growth daylength, ambient CO2 level, and intracellular hydrogen peroxide (H2O2) availability all impact plant function by modulating signalling pathways, but interactions between them remain unclear. Using a whole-genome transcriptomics approach, we exploited the conditional photorespiratory nature of the catalase-deficient cat2 mutant to identify gene expression patterns responding to these three factors. Arabidopsis Col-0 and cat2 grown for 5 weeks in high CO2 in short days (SD) were transferred to air in SD or long days (LD), and microarray analysis was performed. Of more than 500 genes differentially expressed in Col-0 between high CO2 and transfer to air in SD, the response of about one-third was attenuated by transfer to air in LD. H2O2-responsive genes in cat2 were highly dependent on daylength. The majority of H2O2-induced genes were more strongly up-regulated after transfer to air in SD than to LD, while a smaller number showed an opposing pattern. Responses of other H2O2-dependent genes indicate redox-modulation of the daylength control of fundamental cell processes. The overall analysis provides evidence that (1) CO2 level modulates stress-associated gene expression; (2) both CO2 and H2O2 interact with daylength and photoreceptor signalling pathways; and (3) cellular signalling pathways may be primed to respond to increased H2O2 in a daylength-determined manner.
Publication Title
Day length is a key regulator of transcriptomic responses to both CO(2) and H(2)O(2) in Arabidopsis.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Alterations of hydrogen peroxide (H2O2) levels have a profound impact on numerous signaling cascades orchestrating stress responses, plant growth and development, including programmed cell death. To expand the repertoire of known molecular mechanisms implicated in H2O2 signaling, we performed a forward chemical screen to identify small molecules that could alleviate the photorespiratory-induced cell death phenotype of Arabidopsis thaliana mutants lacking H2O2 scavenging capacity by peroxisomal CATALASE2. Here, we report the characterization of pakerine, a m-sulfamoyl benzamide from the sulfonamide family. Pakerine alleviates the cell death phenotype of cat2 mutants exposed to photorespiration-promoting conditions and delays dark-induced senescence in wild type Arabidopsis leaves. By using a combination of transcriptomics, metabolomics and affinity purification we identified ABNORMAL INFLORESCENCE MERISTEM 1 (AIM1) as a putative protein target of pakerine. AIM1 is a 3-hydroxyacyl-CoA dehydrogenase involved in β-fatty acid oxidation that contributes to jasmonic acid (JA) and salicylic acid (SA) biosynthesis. Whereas intact JA biosynthesis was not required for pakerine bioactivity, our results point towards a role for β-oxidation-dependent SA production in execution of H2O2-mediated cell death.
Publication Title
Chemical Genetics Approach Identifies Abnormal Inflorescence Meristem 1 as a Putative Target of a Novel Sulfonamide That Protects Catalase2-Deficient <i>Arabidopsis</i> against Photorespiratory Stress.
Sample Metadata Fields
Specimen part
View Samples- Arabidopsis thaliana
- 25 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Reactive oxygen species (ROS) are key signalling molecules that regulate growth and development and coordinate responses to biotic and abiotic stresses. ROS homeostasis is controlled through a complex network of ROS production and scavenging enzymes. Recently, the first genes involved in ROS perception and signal transduction have been identified and, currently, we are facing the challenge to uncover the other players within the ROS regulatory gene network. The specificity of ensuing cellular responses depends on the type of ROS and their subcellular production sites. Various experimental systems, including catalase-deficient plants, in combination with genome-wide expression studies demonstrated that increased hydrogen peroxide (H2O2) levels significantly affect the transcriptome of plants and are capable of launching both defence responses and cell death events.
Publication Title
Spatial H2O2 signaling specificity: H2O2 from chloroplasts and peroxisomes modulates the plant transcriptome differentially.
Sample Metadata Fields
Age, Specimen part
View Samples- Arabidopsis thaliana
- 24 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Drought is an important environmental factor affecting plant growth and biomass production. Despite this importance, little is known on the molecular mechanisms regulating plant growth under water limiting conditions. The main goal of this work was to investigate, using a combination of growth and molecular profiling techniques, how Arabidopsis thaliana leaves adapt their growth to prolonged mild osmotic stress. Fully proliferating, expanding and mature leaves were harvested from plants grown on plates without (control) or with 25mM mannitol (osmotic stress) and compared to seedlings at stage 1.03.
Publication Title
Developmental stage specificity and the role of mitochondrial metabolism in the response of Arabidopsis leaves to prolonged mild osmotic stress.
Sample Metadata Fields
Specimen part
View Samples- Arabidopsis thaliana
- 36 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Stresses that target mitochondrial function lead to altered transcriptional responses for 100-1000s of genes genome wide, and are signalled via retrograde communication pathways within the cell. rao2 mutants contain a mutation in the NAC family transcription factor ANAC017 and cannot induce stress responsive genes (such as the mitochondrial alternative oxidase 1a) in response to mitochondrial dysfunction. We sought to define the global gene network regulated through RAO2 function in response to mitochondrial stress (mimicked through treatment of plants with antimycin A - a specific inhibitor of complex III in the mitochondrial electron transfer chain), and non-specific stress signals such as hydrogen peroxide. We have defined global stress responses that are positively and negatively mediated by RAO2 function, and show that greater than 80% of transcripts that are differentially regulated under H2O2 stress require proper functioning of ANAC017 for a normal stress responses.
Publication Title
A membrane-bound NAC transcription factor, ANAC017, mediates mitochondrial retrograde signaling in Arabidopsis.
Sample Metadata Fields
Treatment
View Samples- Arabidopsis thaliana
- 9 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Hydrogen peroxide (H2O2) can act as a signaling molecule that influences various aspects of plant growth and development, including stress signaling and cell death. Catalase deficient plants are pioneering systems which accumulate hydrogen peroxide (H2O2) from peroxisomal origin during photorespiratory challenges. Respiratory burst oxidase homologues D and F are known to participate in intracellular oxidative stress response launched in cat2 mutants (Chaouch et al., 2012). We studied the compared the transcriptional response of cat2 rbohD and cat2 rbohF double mutants versus the cat2 background to further adress their role during photorespiratory stress.
Publication Title
The ROS Wheel: Refining ROS Transcriptional Footprints.
Sample Metadata Fields
Age
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Hydrogen peroxide (H2O2) is a potent signaling molecule influencing various aspects of plant growth and development. Its limited lifetime and specific production sites in the plant cell necessitate the existence of specialized mechanisms that relay H2O2-encoded information. To discover such mechanisms, we focused on peroxisomal H2O2 production triggered by enhanced photorespiration in Arabidopsis mutants lacking catalase activity (cat2-2), and looked for second-site mutations that attenuate the negative effects (Fv'/Fm' decline and lesion formation) of H2O2 build up. A mutation residing in the GRAS family transcriptional regulator SHORT-ROOT (SHR) was found to underlie the increased performance of cat2-2 knock-outs under photorespiratory stress. In contrast to shr, introduction of the scr mutation in cat2-2 background did not improve the photorespiratory performance of plants lacking peroxisomal catalase. The absence of SHR negatively affected the activity of the photorespiratory enzymes glycolate oxidase and catalase, which was accompanied with elevated glycolate content and inability to accumulate glycine under conditions promoting photorespiration. The transcriptome signature of cat2-2 shr-6 double mutants exposed to photorespiratory stress lacked jasmonate-dependent signaling components, otherwise induced in cat2-2. The photorespiratory phenotype of cat2-2 was found to be modulated by exogenous sugars both in the presence and absence of shr. Taken together, these findings highlight a crucial role for SHR in H2O2 signal transduction and stress tolerance.
Publication Title
The ROS Wheel: Refining ROS Transcriptional Footprints.
Sample Metadata Fields
Age, Specimen part, Treatment, Time
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Six weeks old Arabidopsis plants were transferred to a low CO2 (100 ppm) environment during 24 hours and compared to control plants kept under ambient CO2 conditions. Limited CO2 availability will cause higher rates of photorespiration and affect the plant redox homeostasis. We studied the transcriptomic impact of exposing plants to a lower CO2 environment to further eliculidate the signaling pathways during photorespiratory stress.
Publication Title
The ROS Wheel: Refining ROS Transcriptional Footprints.
Sample Metadata Fields
Age, Treatment
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Excessive levels of reactive oxygen species (ROS) cause cellular stress through damage to all classes of macromolecules and result in cell death. However, ROS can also act as signaling molecules in various biological processes. In plants, ROS signaling has been documented in environmental stress perception, plant development and cell death amongst others. Knowledge on the regulatory events governing ROS signal transduction is however still scratching the surface. To further elucidate the transcriptional response and regulation upon ROS accumulation we supplemented Arabidopsis seedlings with a 10mM hydrogen peroxide (H2O2) solution to trigger oxidative stress.
Publication Title
The ROS Wheel: Refining ROS Transcriptional Footprints.
Sample Metadata Fields
Age, Specimen part
View Samples