Project description:Plant responses to abiotic stresses are accompanied by massive changes in transcriptome composition. To provide a comprehensive view of stress-induced changes in the Arabidopsis thaliana transcriptome, we have used whole-genome tiling arrays to analyze the effects of salt, osmotic, cold and heat stress as well as application of the hormone abscisic acid (ABA), an important mediator of stress responses.
Project description:Micro RNAs (miRNAs) are a class of small endogenous RNAs conserved in eukaryotic organisms including plants. They suppress gene expression post-transcriptionally in many different biological processes. Previously, we reported salinity-induced changes in gene expression in transgenic Arabidopsis thaliana plants that constitutively expressed a pea abscisic acid-responsive (ABR17) gene. In the current study, we used a microarray to investigate the role of miRNA-mediated post-transcriptional gene regulation in these same transgenic plants in the presence and absence of salinity stress. We identified nine miRNAs that were significantly modulated due to ABR17 gene expression, and seven miRNAs that were modulated in response to salt stress. The target genes regulated by these miRNAs were identified using starBase (sRNA target Base) Degradome analysis and through 5' RNA Ligase Mediated-Rapid Amplification of cDNA Ends (RLM-RACE). Our findings revealed miRNA:mRNA interactions comprising regulatory networks of Auxin Response Factor (ARF), ARGONAUTE 1, (AGO1), Dicer-like proteins 1 (DCL1), Squamosa Promoter Binding (SPB), NAC, APETALA 2 (AP2), Nuclear Factor-Y (NFY), RNA binding proteins, Arabidopsis thaliana vacuolar phyrophosphate 1 (AVP1) and Pentatricopetide repeat (PPR) in ABR17 transgenic A. thaliana, which control physiological, biochemical and stress signalling cascades due to the imposition of salt stress. Our results are discussed within the context of the effect of the transgene, ABR17, and the roles miRNA expression may play in mediating plant responses to salinity.
Project description:Micro RNAs (miRNAs) are a class of small endogenous RNAs conserved in eukaryotic organisms including plants. They suppress gene expression post-transcriptionally in many different biological processes. Previously, we reported salinity-induced changes in gene expression in transgenic Arabidopsis thaliana plants that constitutively expressed a pea abscisic acid-responsive (ABR17) gene. In the current study, we used a microarray to investigate the role of miRNA-mediated post-transcriptional gene regulation in these same transgenic plants in the presence and absence of salinity stress. We identified nine miRNAs that were significantly modulated due to ABR17 gene expression, and seven miRNAs that were modulated in response to salt stress. The target genes regulated by these miRNAs were identified using starBase (sRNA target Base) Degradome analysis and through 5' RNA Ligase Mediated-Rapid Amplification of cDNA Ends (RLM-RACE). Our findings revealed miRNA:mRNA interactions comprising regulatory networks of Auxin Response Factor (ARF), ARGONAUTE 1, (AGO1), Dicer-like proteins 1 (DCL1), Squamosa Promoter Binding (SPB), NAC, APETALA 2 (AP2), Nuclear Factor-Y (NFY), RNA binding proteins, Arabidopsis thaliana vacuolar phyrophosphate 1 (AVP1) and Pentatricopetide repeat (PPR) in ABR17 transgenic A. thaliana, which control physiological, biochemical and stress signalling cascades due to the imposition of salt stress. Our results are discussed within the context of the effect of the transgene, ABR17, and the roles miRNA expression may play in mediating plant responses to salinity. In this miRNA-microarray experiment, a total of 4 samples were analyzed with their 3 biological replicates. Two samples, WT and ABR17 control (without salt treatment), were used as reference controls.
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: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)
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:Plant homeodomain (PHD) finger proteins affect growth and development by regulating transcription and reading epigenetic modifications of histones, but their functions in abiotic stress responses remain largely unclear. Here we characterize seven Arabidopsis thaliana Alfin1-like PHD finger proteins (ALs) in the response to abiotic stresses. ALs localize to the nucleus and repress transcription. Except AL6, all the ALs bind to G-box element. Changes of the amino acids at positions 34 and 35 in AL6 cause the loss of G-box binding ability. Expression of the ALs responded differently to osmotic stress, salt, cold and abscisic acid treatments. AL5 was induced by multiple stresses, and AL5-overexpressing plants showed higher tolerance to salt, drought and freezing stress than Col-0. Also, al5 mutants showed reduced stress tolerance. ChIP-Seq assay helps find the direct targets of AL5.
Project description:Biotic and abiotic stresses limit agricultural yields, and plants are often simultaneously exposed to multiple stresses. Combinations of stresses such as heat and drought or cold and high light intensity, have profound effects on crop performance and yeilds To analyze such responses, we initially compared transcriptome changes in ten Arabidopsis thaliana ecotypes using cold, heat, high light, salt and flagellin treatments as single stress factors or their double combinations. Arabidopsis thaliana plants of ecotypes (Col, Ler, C24, Cvi, Kas1, An1, Sha, Kyo2, Eri and Kond) were subjected to the following stress treatments: Salt, Cold, Heat, High Light (HL), Salt+Heat, Salt+HL, Cold+HL, Heat+HL, as well as FLG (Flagellin, flg22 peptide), Cold+FLG, Heat+FLG
Project description:To investigate differences in plant responses to salt and ABA stimulus, differences in gene expression in Arabidopsis in response to salt and ABA were compared using an Agilent oligo microarray. Four-week-old Arabidopsis thaliana ecotype Columbia (Col-0) seedlings were treated with either 150 mM NaCl or 10 μM ABA for 6 hours; unstressed seedlings (control sample) were collected in parallel to avoid the possible effects of circadian rhythms. The results revealed that 31 genes were up regulated by both NaCl and ABA stress, and 23 genes were down-regulated by these stressors. To provide further validation of our microarray experiment data, ten genes from this signature were quantified in the same RNA samples by quantitative real-time PCR.