Project description:Genes of the of Arabidopsis thaliana guard cells transcriptome that respond to high CO2 and darkness were identified and compared to the ABA- and low humidity treated samples of Experiment GSE41054 in Arabidopsis thaliana enriched guard cell samples.
Project description:Plants acclimate to drought and water stress through diverse physiological responses, primarily mediated by the hormone abscisic acid (ABA). The closure of stomatal pores on aerial surfaces of plants is one of the rapid responses mediated by ABA to reduce transpirational water loss because plants lose the majority of their water through stomatal pores. Stomatal guard cells have been an important cellular system for studying ABA signaling. The dynamic changes in the transcriptome of stomatal guard cells in response to ABA have been investigated in the model plant Arabidopsis thaliana. In this study, we analyzed the dynamics of ABA-regulated transcriptomes in stomatal guard cells of Brassica napus.
Project description:In plants, epidermal guard cells integrate and respond to numerous environmental signals to control stomatal pore apertures thereby regulating gas exchange. Chromatin structure controls transcription factor access to the genome, but whether large-scale chromatin remodeling occurs in guard cells during stomatal movements, and in response to the hormone abscisic acid (ABA) in general, remain unknown. Here we isolate guard cell nuclei from Arabidopsis thaliana plants to examine whether the physiological signals, ABA and CO2, regulate guard cell chromatin during stomatal movements. Our cell type specific analyses uncover patterns of chromatin accessibility specific to guard cells and define novel cis-regulatory sequences supporting guard cell specific gene expression. We find that ABA triggers extensive and dynamic chromatin remodeling in guard cells, roots, and mesophyll cells with clear patterns of cell-type specificity. DNA motif analyses uncover binding sites for distinct transcription factors enriched in ABA-induced and ABA-repressed chromatin. We identify the ABF/AREB bZIP-type transcription factors that are required for ABA-triggered chromatin opening in guard cells and implicate the inhibition of a set of bHLH-type transcription factors in controlling ABA-repressed chromatin. Moreover, we demonstrate that ABA and CO2 induce distinct programs of chromatin remodeling. We provide insight into the control of guard cell chromatin dynamics and propose that ABA-induced chromatin remodeling primes the genome for abiotic stress resistance.
Project description:In plants, epidermal guard cells integrate and respond to numerous environmental signals to control stomatal pore apertures thereby regulating gas exchange. Chromatin structure controls transcription factor access to the genome, but whether large-scale chromatin remodeling occurs in guard cells during stomatal movements, and in response to the hormone abscisic acid (ABA) in general, remain unknown. Here we isolate guard cell nuclei from Arabidopsis thaliana plants to examine whether the physiological signals, ABA and CO2, regulate guard cell chromatin during stomatal movements. Our cell type specific analyses uncover patterns of chromatin accessibility specific to guard cells and define novel cis-regulatory sequences supporting guard cell specific gene expression. We find that ABA triggers extensive and dynamic chromatin remodeling in guard cells, roots, and mesophyll cells with clear patterns of cell-type specificity. DNA motif analyses uncover binding sites for distinct transcription factors enriched in ABA-induced and ABA-repressed chromatin. We identify the ABF/AREB bZIP-type transcription factors that are required for ABA-triggered chromatin opening in guard cells and implicate the inhibition of a set of bHLH-type transcription factors in controlling ABA-repressed chromatin. Moreover, we demonstrate that ABA and CO2 induce distinct programs of chromatin remodeling. We provide insight into the control of guard cell chromatin dynamics and propose that ABA-induced chromatin remodeling primes the genome for abiotic stress resistance.
Project description:To identify genes of the guard cell transcriptome of Arabidopsis thaliana enriched guard cell samples were compared with total leaf tissue. Genes of the abscisic acid and humidity response of Arabidopsis thaliana guard cells were identified by treatment with ABA-Spray and low humidity. total samples analysed are 24: 4 biological independent replicates of: total leaf (COL-0) vs. enriched guard cells (COL-0); ABA-sprayed enriched guard cells (gl1-1) vs. control-sprayed enriched guard cells (gl1-1); low humidity (20%rh) treated enriched guard cells (COL-0) vs. high humidity (80%) treated enriched guard cells (COL-0)
Project description:To identify genes of the guard cell transkriptome of Arabidopsis thaliana enriched guard cell samples were compared with total leaf tissue. Genes of the abscisic acid and humidity response of Arabidopsis thaliana guard cells were identified by treatment with ABA-Spray and low humidity. Ost1-2 and slac1-3 mutants were compared to their wildtype. total samples analysed are 35: 4 biolocigal independent replicates of: total leaf (COL-0) vs. enriched guard cells (COL-0); ABA-sprayed enriched guard cells (gl1-1) vs. control-sprayed enriched guard cells (gl1-1); enriched guard cells (slac1-3) vs. enriched guard cells (gl1-1);guard cells (ost1-2) vs. guard cells (ler);low humidity(20%rh) treated enriched guard cells (COL-0) vs. high humidity(80%) treated enriched guard cells (COL0)
Project description:To identify genes of the guard cell transcriptome of Arabidopsis thaliana enriched guard cell samples were compared with total leaf tissue. Genes of the abscisic acid and humidity response of Arabidopsis thaliana guard cells were identified by treatment with ABA-Spray and low humidity.
Project description:To identify genes of the guard cell transkriptome of Arabidopsis thaliana enriched guard cell samples were compared with total leaf tissue. Genes of the abscisic acid and humidity response of Arabidopsis thaliana guard cells were identified by treatment with ABA-Spray and low humidity. Ost1-2 and slac1-3 mutants were compared to their wildtype.
Project description:Heterotrimeric G proteins mediate crucial and diverse signaling pathways in eukaryotes. To gain insights into the regulatory modes of the G protein and the co-regulatory modes of the G protein and the stress hormone abscisic acid (ABA), we generated and analyzed gene expression in G protein subunit single and double mutants of the model plant Arabidopsis thaliana. Through a Boolean modeling approach, our analysis reveals novel modes of heterotrimeric G protein action. Keywords: transcriptome analysis; G protein subunit mutants; abscisic acid (ABA) Microarray data were generated from four genotypes (wild type, gpa1-4 mutant, agb1-2 mutant, agb1-2 gpa1-4 double mutant) with or without ABA treatment. Arabidopsis plants were grown in growth chambers with an 8 hr light/16hr dark. Three hundred Arabidopsis leaves excised from 60-70 five-week-old plants were used as the starting material for each guard cell microarray. Ten mature leaves taken from 3-4 plants grown side-by side with the plants for guard cell isolation were used for each leaf sample. Excised leaf and isolated guard cell samples were treated with ABA (50 μM) or EtOH (solvent control) for 3 hrs. For each type of sample (guard cells or leaves), three independent biological replicates were performed, resulting in a total of 48 microarray hybridizations (2 sample types ´ 4 genotypes ´ two treatments ´3 replicates).