Project description:AtGenExpress: A multinational coordinated effort to uncover the transcriptome of the multicellular model organism Arabidopsis thaliana; The activity of genes and their encoded products can be regulated in several ways, but transcription is the primary level, since all other modes of regulation (RNA splicing, RNA and protein stability, etc.) are dependent on a gene being transcribed in the first place. The importance of transcriptional regulation has been underscored by the recent flood of global expression analyses, which have confirmed that transcriptional co-regulation of genes that act together is the norm, not the exception. Moreover, many studies suggest that evolutionary change is driven in large part by modifications of transcriptional programs. An essential first step toward deciphering the transcriptional code is to determine the expression pattern of all genes. With this goal in mind, an international effort to develop a gene expression atlas of Arabidopsis has been underway since fall 2003. This project, dubbed AtGenExpress, is funded by the DFG, and will provide the Arabidopsis community with access to a large set of Affymetrix microarray data. As part of this collaboration, we have generated expression data from 80 biologicaly different samples in triplicate. This experiment studies the effect of two concentrations of ABA during seed imbibition in the Col-0 ecotype. Experimenter name = Eiji Nambara , Kazumi Nakabayashi , Yuji Kamiya; Experimenter institute = AtGenExpress Experiment Overall Design: 8 samples were used in this experiment
Project description:AtGenExpress: A multinational coordinated effort to uncover the transcriptome of the multicellular model organism Arabidopsis thaliana The activity of genes and their encoded products can be regulated in several ways, but transcription is the primary level, since all other modes of regulation (RNA splicing, RNA and protein stability, etc.) are dependent on a gene being transcribed in the first place. The importance of transcriptional regulation has been underscored by the recent flood of global expression analyses, which have confirmed that transcriptional co-regulation of genes that act together is the norm, not the exception. Moreover, many studies suggest that evolutionary change is driven in large part by modifications of transcriptional programs. An essential first step toward deciphering the transcriptional code is to determine the expression pattern of all genes. With this goal in mind, an international effort to develop a gene expression atlas of Arabidopsis has been underway since fall 2003. This project, dubbed AtGenExpress, is funded by the DFG, and will provide the Arabidopsis community with access to a large set of Affymetrix microarray data. As part of this collaboration, we have generated expression data from 80 biologicaly different samples in triplicate. This experiment studies the effect of two concentrations of ABA during seed imbibition in the Col-0 ecotype. Experimenter name = Eiji Nambara , Kazumi Nakabayashi , Yuji Kamiya Experimenter institute = AtGenExpress Keywords: Effect of ABA
Project description:Karrikins promote seed germination in Arabidopsis thaliana. Completion of germination (protrusion of the radicle) is not observed until ~72 h in dormant wildtype seed under these conditions. We used microarrays to examine karrikin-induced transcriptional changes after 24 h of imbibition. Transcriptional changes may indicate events leading to karrikin-induced germination or karrikin-specific markers.
Project description:Wheat seed germination and seminal root growth can be inhibited by treatment with exogenous ABA We used Affymetrix GeneChip Wheat Genome Array to detail transcriptional programs affected by ABA during imbibition After-ripened seeds imbibed in ABA for 24 h were used for RNA extraction and hybridization on Affymetrix GeneChip. After-ripened seeds were generated by storing dormant seeds at room temperature for 10 months.
Project description:Wheat seed dormancy is released by after-ripening, and germination and seminal root growth of after-ripened/non-dormant seeds can be inhibited by treatment with exogenous ABA. We used Affymetrix GeneChip Wheat Genome Array to detail transcriptional programs affected by after-ripening of dormant seeds and imbibition of after-ripened seeds in ABA.
Project description:Histone acetylation is involved in the regulation of gene expression in plants and eukaryotes. Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from histones, which is associated with the repression of gene expression. To study the role of histone acetylation in the regulation of gene expression during seed germination, trichostatin A (TSA), a specific inhibitor of histone deacetylase, was used to treat imbibing Arabidopsis thaliana seeds. GeneChip arrays were used to show that TSA induces up-regulation of 45 genes and down-regulation of 27 genes during seed germination. Eight TSA-up-regulated genes were selected for further analysis - RAB18, RD29B, ATEM1, HSP70 and four late embryogenesis abundant protein genes (LEA). A gene expression time course shows that these eight genes are expressed at high levels in the dry seed and repressed upon seed imbibition at an exponential rate. In the presence of TSA, the onset of repression of the eight genes is not affected but the final level of repressed expression is elevated. Chromatin immunoprecipitation and HDAC assays show that there is a transient histone deacetylation event during seed germination at one day after imbibition, which serves as a key developmental signal that affects the repression of the eight genes. Experiment Overall Design: Two samples (TSA-treated v.s. untreated). Two replicates for each sample.
Project description:Seed maturation, dormancy and germination are distinct physiological processes. Transition from maturation to dormancy, and from dormancy into germination are not only critical developmental phases in the plant life cycle but are also important agricultural traits. These developmental processes and their phase transitions are fine determined and coordinately regulated by genetic makeup and environmental cues. SCARECROW-LIKE15 (SCL15) has been demonstrated to be essential for repressing the seed maturation programme in vegetative tissues (Gao et al., Nat Commun, 2015, 6:7243). Here we report that SCL15 is also important for seed dormancy maintenance, germination timing and seed vigor performance based on the effects of SCL15 mutation on plant germination, growth and reproduction when compared with wild type Arabidopsis and over-expression lines 35S:SCL15 and Napin:SCL15. Seed dormancy is enhanced by the mutation of SCL15 in a GA signaling dependent way, indicating that SCL15 plays a negative role for primary dormancy release. Seed germination is positively regulated by SCL15 through interaction with ABA, GA and auxin signaling. SCL15 acts as positive regulator of seed vigor and effect of SCL15 mRNA abundance on seed reserve accumulation and seed development during late embryogenesis may contribute to the seed vigor performance.
Project description:Karrikins promote seed germination in Arabidopsis thaliana. Completion of germination (protrusion of the radicle) is not observed until ~72 h in dormant wildtype seed under these conditions. We used microarrays to examine karrikin-induced transcriptional changes after 24 h of imbibition. Transcriptional changes may indicate events leading to karrikin-induced germination or karrikin-specific markers. Primary dormant seed of wildtype (which can germinate and is promoted by KAR1) and ga1-3 (which cannot germinate, and is not promoted by KAR1) were imbibed on water-agar or 1 uM KAR1 in the light at 20 C and assayed for gene expression after 24 h. Three or four biological replicates per genotype/treatment.
Project description:Histone acetylation is involved in the regulation of gene expression in plants and eukaryotes. Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from histones, which is associated with the repression of gene expression. To study the role of histone acetylation in the regulation of gene expression during seed germination, trichostatin A (TSA), a specific inhibitor of histone deacetylase, was used to treat imbibing Arabidopsis thaliana seeds. GeneChip arrays were used to show that TSA induces up-regulation of 45 genes and down-regulation of 27 genes during seed germination. Eight TSA-up-regulated genes were selected for further analysis - RAB18, RD29B, ATEM1, HSP70 and four late embryogenesis abundant protein genes (LEA). A gene expression time course shows that these eight genes are expressed at high levels in the dry seed and repressed upon seed imbibition at an exponential rate. In the presence of TSA, the onset of repression of the eight genes is not affected but the final level of repressed expression is elevated. Chromatin immunoprecipitation and HDAC assays show that there is a transient histone deacetylation event during seed germination at one day after imbibition, which serves as a key developmental signal that affects the repression of the eight genes. Keywords: histone deacetylase inhibitor, developmental effects