Project description:Identification of differentially expressed genes in Arabidopsis thaliana mutants in response to combined abiotic stress treatment through Microarray experiment.
Project description:GSH, being a versatile molecule, is actively involved in various bilogical processe of plant system. Our previous studies identifies an active role of GSH in plant defense signaling network. Here, we used microarray under GSH treated condition to obtain a global expression profiling under this altered GSH conditions.
Project description:GSH, being a versatile molecule, is actively involved in various bilogical processe of plant system. Our previous studies identifies an active role of GSH in plant defense signaling network. Here, we used microarray under GSH treated condition to obtain a global expression profiling under this altered GSH conditions. We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process. A.thaliana, much accalimed model system of plant biology and being fully sequenced, we used this system to explore the specific relation of GSH with metabolic processes, phisiological conditions, etc.
Project description:The genome of Arabidopsis contains 122 ERF transcription factor genes, some of which play diverse roles in the development and stress responses. A previous transcriptome analysis of Arabidopsis revealed that gene expression under combinatory stress conditions is not predictable from the combination of individual stresses (GSE46760). Searching for commonly regulated genes verified that only 11 genes were regulated in all stress combinations . Among these 11 genes, Rap2.9 (AT4G06746) was down-regulated under all stress conditions. Transgenic Arabidopsis thaliana lines overexpressing Rap2.9 under CaMV 35S promotor were generated, and the microarray analysis revealed that overexpression of Rap2.9 in A. thaliana plants causes massive reprogramming of transcription resulting in the alteration of the hormonal homeostasis and imbalances in signalling cascades related to stress response. Further analysis also revealed that Rap2.9 played an crucial role in plant development and stress tolerance in Arabidopsis plants.
Project description:Keeping imbibed seeds at low temperatures for a certain period, so called seed vernalization (SV) treatment, promotes seed germination and subsequent flowering in various plants. Vernalization-promoting flowering requires GSH. However, the expression patterns analyzed by GeneChip arrays showed that increased GSH biosynthesis partially mimics SV treatment in Arabidopsis thaliana. SV treatment (keeping imbibed seeds at 4°C for 24 h) induced a specific pattern of gene expression and promoted subsequent flowering in wild-type plants. A similar pattern was observed at 22°C in transgenic plants (35S-GSH1 plants) overexpressing the γ-glutamylcysteine synthetase gene GSH1, coding an enzyme limiting GSH biosynthesis, under the control of the cauliflower mosaic virus 35S promoter. This pattern was strengthened at 4°C but flowering was less responsive to SV treatment. There was a difference in the transcript behaviour of the flowering repressor FLC between wild-type and 35S-GSH1 plants. Unlike other genes responsive to SV treatment, SV-dependent decrease in FLC in wild-type plants was reversed in 35S-GSH1 plants. SV treatment increased GSSG level in wild-type seeds, whereas GSSG level was high in 35S-GSH1 plants, even at a non-vernalizing temperature. Taking into consideration that low temperatures stimulate GSH biosynthesis and bring about oxidative stress, GSSG is considered to trigger low temperature response, but enhanced GSH synthesis was not enough for mimicking SV treatment. To complete it, it essentially required the cellular redox retransition from the oxidized to the reduced state that is observed after the seed vernalization treatment. Four samples (Col-0 and 35S-GSH1 seeds imbibed at 22˚C or 4˚C). Two replicates for each samples.
Project description:Keeping imbibed seeds at low temperatures for a certain period, so called seed vernalization (SV) treatment, promotes seed germination and subsequent flowering in various plants. Vernalization-promoting flowering requires GSH. However, the expression patterns analyzed by GeneChip arrays showed that increased GSH biosynthesis partially mimics SV treatment in Arabidopsis thaliana. SV treatment (keeping imbibed seeds at 4°C for 24 h) induced a specific pattern of gene expression and promoted subsequent flowering in wild-type plants. A similar pattern was observed at 22°C in transgenic plants (35S-GSH1 plants) overexpressing the γ-glutamylcysteine synthetase gene GSH1, coding an enzyme limiting GSH biosynthesis, under the control of the cauliflower mosaic virus 35S promoter. This pattern was strengthened at 4°C but flowering was less responsive to SV treatment. There was a difference in the transcript behaviour of the flowering repressor FLC between wild-type and 35S-GSH1 plants. Unlike other genes responsive to SV treatment, SV-dependent decrease in FLC in wild-type plants was reversed in 35S-GSH1 plants. SV treatment increased GSSG level in wild-type seeds, whereas GSSG level was high in 35S-GSH1 plants, even at a non-vernalizing temperature. Taking into consideration that low temperatures stimulate GSH biosynthesis and bring about oxidative stress, GSSG is considered to trigger low temperature response, but enhanced GSH synthesis was not enough for mimicking SV treatment. To complete it, it essentially required the cellular redox retransition from the oxidized to the reduced state that is observed after the seed vernalization treatment.
Project description:Crop plants are often exposed to the combination of drought and pathogen stress. Transcriptome studies on Arabidopsis thaliana and other plants unveiled activation of shared molecular defense mechanisms between under individual and combined stresses. These shared plant responses are characterized by commonly regulated genes under individual and combined stresses. Based on the previous studies, G-box binding factor 3 (GBF3) is one of the regulatory components of such shared responses. However, the mechanistic understanding on the role of GBF3 under combined drought and pathogen stress is not yet decoded. Using genetic approaches, we demonstrated Atgbf3 mutant plants are more susceptible under individual and combined drought and Pseudomonas syringae pv. tomato DC3000 stresses as compared to the wild-type plants. We further analyzed the global transcriptome of Atgbf3 mutant under combined stress to identify its downstream targets to further validate the role of AtGBF3 in combined stress. We used microarrays to detail the global transcriptome reprogramming during AtGBF3-mediated regulation of combined stress.