Transcriptome responses to combined biotic and abiotic stresses in Arabidopsis thaliana
ABSTRACT: 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:We generated a comprehensive RNAseq expression atlas for several stress conditions in order to analyze changes in the gene expression during adaptation to mild stresses. The stresses are divided into two main groups: the “nutrient stresses” and the “environmental stresses”. Nutrient stresses include nutrient depletion (-N, -P, -S, -micronutrients), salt stress (+NaCl), osmotic stress (+mannitol) and control. The environmental stresses consist of high light, prolonged darkness, heat, cold and control.
Project description:We performed poly(A)+, poly(A)-, nuclear, small RNA-seq analysis on Oryza sativa japonica WT plants. Overall design: We treated the seedlings under the stress conditions, including cold, drought, heat, high-salt, and high-light. Also, we choose two tissues, roots and panicles for RNA sequencing.
Project description:To identify novel miRNA and NAT-siRNAs that are associated with salt and cold stresses in Arabidopsis, we generated small RNA sequences from Arabidopsis plants under salt and cold stress treatments. Sequencing of small RNAs in Arabidopsis under salt, and cold stress conditions.
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. Overall design: After seedlings had been grown for 10 days on solid MS medium at 21°C, they were transferred to liquid MS medium containing no additives (mock control), 200 mM NaCl (salt stress), 300 mM mannitol (osmotic stress) or 100 μM ABA. For cold and heat stress, seedlings were transferred to pre-chilled or pre-warmed liquid MS medium and incubated at 8°C and 30°C, respectively. Samples were taken after 1 h and 12 h of continuous stress treatment. RNA was extracted from whole seedlings and converted into double stranded DNA targets that were hybridized to whole genome tiling arrays (Affymetrix Arabidopis Tiling1.0R®). All hybridizations were performed with 3 biological replicates.
Project description:In natural habitats, plants are often exposed to multiple stresses. Most studies, however, for plant abiotic stress responses analyzed those to individual stress but not combined stresses. In this report, we performed comparison analyses of gene expression to individual stresses, salt, osmotic and heat, and to a combination of these three stresses, which mimics arid conditions. We show here that the combined stress treatment induces unique gene expression pattern but not a simple reflection of the additive effects of individual stresses. First, the number of genes induced by combined stresses (150 mM NaCl, 200 mM mannitol and 35°C heat) was much smaller when compared to the sum of those induced by individual stress treatments, while the number of genes downregulated by multiple stresses was larger. A large number of genes induced by mannitol were not induced by multiple stresses, while those induced by salts were less affected in combined stress treatments. In addition, 125 genes, including13 for transcription factors, were found to be induced specifically by combined stress treatments. We report here that the plant response to a multi-stress environment represents an output of complex interactions between different stress aspects and signaling events of the various components of this environmental situation, and the determinative factor in this response is to avoid/minimize the antagonistic effects and to magnify the synergistic features of the imposed environmental challenges. Based on our results, we propose that genes that are highly induced by multiple treatments may be candidate for engineering stress tolerant crop plants. Wild-type plants of Arabidopsis thaliana were treated with three abiotic stresses, high salinity (150mM and 300mM), high osmotic pressure (200mM and 400mM mannitol) and heat (35°C), individually or simultaneously. Plants were treated with salt or mannitol for 16 hrs (first 1 hr and last 7 hrs are in light and other time in dark) or with heat for 4 hrs (in light) before sampling. There are three biologcal replicates.
Project description:To identify novel miRNA and NAT-siRNAs that are associated with abiotic stresses in maize, we generated small RNA sequences from maize seedlings that grew under control and under dought, salt, and cold stress treatments. Overall design: Sequencing of small RNAs in maize under control, drought, salt, and cold stress conditions.
Project description:To identify novel miRNA and NAT-siRNAs that are associated with abiotic stresses in sorghum, we generated small RNA sequences from sorghum seedlings that grew under control and under dought, salt, and cold stress treatments. sequencing of small RNAs in sorghum under control, drought, salt, and cold stress conditions.
Project description:To identify novel miRNA and NAT-siRNAs that are associated with abiotic stresses in maize, we generated small RNA sequences from maize seedlings that grew under control and under dought, salt, and cold stress treatments. Sequencing of small RNAs in maize under control, drought, salt, and cold stress conditions.
Project description:ABSTRACT: Exposure to abiotic stresses triggers global changes in the expression of thousands of eukaryotic genes at the transcriptional 70 and post-transcriptional levels. Small RNA (smRNA) pathways and splicing both function as crucial mechanisms regulating stress-responsive gene expression. However, examples of smRNAs regulating gene expression remain largely limited to effects on mRNA stability, translation, and epigenetic regulation. Also, our understanding of the networks controlling plant gene expression in response to environmental changes, and examples of these regulatory pathways intersecting, remains limited. Here, to investigate the role of smRNAs in stress responses we examined smRNA transcriptomes of Brachypodium distachyon plants subjected to various abiotic stresses. We found that exposure to different abiotic stresses specifically induced a group 75 of novel, endogenous small interfering RNAs (stress-induced, UTR-derived siRNAs, or sutr-siRNAs) that originate from the 3′ UTRs of a subset of coding genes. Our bioinformatics analyses predicted that sutr-siRNAs have potential regulatory functions and that over 90% of sutr-siRNAs target intronic regions of many mRNAs in trans. Importantly, a subgroup of these sutr- siRNAs target the important intron regulatory regions, such as branch point sequences, that could affect splicing. Our study indicates that in Brachypodium, sutr-siRNAs may affect splicing by masking or changing accessibility of specific cis-elements 80 through base-pairing interactions to mediate gene expression in response to stresses. We hypothesize that this mode of regulation of gene expression may also serve as a general mechanism for regulation of gene expression in plants and potentially in other eukaryotes. Analysis of smRNA populations in Brachypodium plants challenged by abiotic stresses: To profile the populations of smRNAs in the model monocot Brachypodium distachyon and examine their regulation in response to abiotic stresses, we conducted high-throughput sequencing of small RNAs from plants exposed to four different abiotic stress conditions, cold, heat (air), heat (water immersion), and salt, in the wild type Brachypodium cultivar Bd21. For our experiments we used information from the literature to select two time-points for stress durations, short and long, which differed for each stress: cold (6 and 24 hours), heat-air (1 and 3 hours), heat-water (1 and 3 hours), and salt (48 hours). We generated small RNA libraries for Illumina sequencing (GAII) from the leaves of Brachypodium plants subjected to stresses and selected smRNAs between 15 and 40 nt in length, which we mapped to the Brachypodium genome.