Transcriptome analysis reveals crosstalk of responsive genes to multiple abiotic stresses in cotton (Gossypium hirsutum L.)
ABSTRACT: Abiotic stress is a major environmental factor that limits cotton growth and yield, moreover, this problem has become more and more serious recently and multiple stresses often occur simultaneously due to the global climate change and environmental pollution. We used microarrays to analyze the crosstalk of responsive genes to multiple abiotic stresses including ABA, cold, drought, salinity and alkalinity in cotton. Cotton seedlings with different abiotic stress treatment were selected at 14-day after germination for RNA extraction and hybridization on Affymetrix microarrays. We sought to identify genes involved in diverse stresses including abscisic acid (A), cold (C), drought (M), salinity (N) and alkalinity (P) by comparative microarray analysis (3 biological replicates for each abiotic stress treatment).
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.
Project description:Soybean, which provides abundant proteins and edible oil, is an important crop; however, it is very sensitive to flooding stress. The growth and grain yields of soybean are seriously reduced by flooding stress. To explore the initial flooding-tolerant mechanism of soybean, flooding-tolerant mutant line and ABA treated soybean were used. Because both material and treatment showed the flooding tolerance, the commonly changed proteins in plants under initial flooding stress were identified. To identify the common proteins, gel free/label free proteomic technique was used.
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:Abiotic stresses such as salinity are very important factors limiting rice growth and productivity around the world. Affymetrix rice genome array containing 48,564 japonica and 1,260 indica sequences was used to analyze the gene expression pattern of rice responsive to salinity stress, try to elucidate the difference of genome-wide gene expression profiling of two contrasting rice genotypes in response to salt stress and to discover the salinity related genes and gene interaction and networks. Under salinity condition, the number of differentially expressed genes (DEGs) in 177-103 was more than that in IR64, and most of up-regulated DEGs in 177-103 are response to stress. But in IR64, most of up-regulated DEGs are transcription related genes. The DEGs under salinity showed very strong tissue specificity, the number of DEGs in leaf was more than that in root. A lot of genes differentially expressed by exogenous ABA treatment under salinity condition, such as Leaf senescence protein, 1-deoxy-D-xylulose 5-phosphate synthase 2 precursor and Protein of unknown function DUF26 were induced by ABA and contributed to salinity tolerance. In this study, the gene expression patterns across two organs including leaves and roots at seedling stage were characterized under control, salinity, salinity+ABA treatments by using the Affymetrix rice microarray platform based on a salinity tolerant rice line derived from IR64.
Project description:Purpose: To identify abiotic stress responsive and tissue specific miRNAs at genome wide level in wheat (Triticum aestivum) Results: Small RNA libraries were constructed from four tissues (root, shoot, mature leaf and spikelets) and three stress treatments of wheat seedlings (control, high temperature, salinity and water-deficit). A total of 59.5 million reads were obtained by high throughput sequencing of eight wheat libraries, of which 32.5 million reads were found to be unique. Using UEA sRNA workbench we identified 47 conserved miRNAs belonging to 20 families, 1030 candidate novel and 51 true novel miRNAs. Several of these miRNAs displayed tissue specific expression whereas few were found to be responsive to abiotic stress treatments. Target genes were predicted for miRNAs identified in this study and their grouping into functional categories revealed that the putative targets were involved in diverse biological processes. RLM-RACE of predicted targets of three conserved miRNAs (miR156, miR160 and miR164) confirmed their mRNA cleavage, thus indicating their regulation at post-transcriptional level by corresponding miRNAs. Expression profiling of confirmed target genes of these miRNAs was also performed. Conclusions: This is the first comprehensive study on profiling of miRNAs in a variety of tissues and in response to several abiotic stresses in wheat. Our findings provide valuable resource for better understanding on the role of miRNAs in stress tolerance as well as plant development. Additionally, this information could be utilized for designing wheat plants for enhanced abiotic stress tolerance and higher productivity. Total eight (three stress, one control and four tissue specific small RNA libraries were pepared and sequenced independently [wheat control (WC), wheat high temperature stressed (WHTS), wheat salinity stressed (WSS) and wheat drought stressed (WDS), wheat shoot(WSH), wheat leaf (WLF), wheat flower(WFL), wheat root(WRT)] on Illumina GAIIx
Project description:Abiotic environmental stresses cause serious economic losses in agriculture. These stresses include temperature extremes, high salinity and drought. To isolate drought-responsive novel coding and noncoding genes, we used the next generation sequencing method from three rice cultivars (wild type nipponbare, nipponbare AP2 transgenic plants, wild type vandana). 36 NGS data of mRNA-seq, small RNA-seq, riboZero-seq were analyzed. For the analyses of these data we constructed a TF-TG (Transcription Factor-Target Gene) network and an ap2 rooted cascading tree. Using these networks and tress we isolated lincRNAs, differentially expressed miRNAs and their targets. We identified several drought stress-related novel/function unknown coding transcripts (transcription factors and functional genes) and non-coding transcripts (small noncoding transcripts such as microRNA and long noncoding transcripts) from these database analyses and have constructed databases of drought stress-related coding and noncoding transcripts Identification of drought-responsive Regulatory Coding and Non-coding Transcripts from rice by deep RNA sequencing
Project description:Cotton premature leaf senescence often occurred with an increasing frequency in many cotton growing areas and caused serious reduction in yield and quality of cotton has been one of the impontant factors that restrict severely the production of cotton.Our laboratory studies showed chilling stress is the key factor that induced A. alternatia infection, caused Alternaria disease and then lead to cotton leaf senescence, but the molecular mechanism of cotton premature leaf senscence is still unclear. We used microarrays to study molecular mechanism of chilling stress causing Alternaria alternata infection and leading to cotton leaf senescence and find the key genes during this process. Plants were grown in growth chamber with a 14/10 hours photoperiod, 28℃/22℃. Three-to-four leaves stage cotton plants were pre-treated by chilling stress with the low temperatures of 16/12℃ day/night for a fixed time length of 3 days. While, the normal growth plants were sustained growing at optimal temperature of 28/20℃ day/night. And then, both chilling stress pre-treated and normal growth cotton plants were inoculated with Alternaria. alternata isolate A1. The mock inoculations were performed with sterilized water. Cotton leaf Samples were respectively collected at 3, 6 days after inoculation (DAI) for RNA extraction and hybridization on Affymetrix microarrays. To that end, we collected 8 samples, i.e. chilling stress pre-treated cotton leaves: 3 DAI (C) and its mock control (D), 6 DAI (E) and its mock control (F); normal growth cotton leaves: 3 DAI (H) and its mock control (I), 6 DAI (J) and its mock control (K). All samples were arranged in completely randomized designed with three replications for each treatment.
Project description:Drought-responsive genes were identified in leaf tissues of the cotton Acala 15-1799, a cotton genotype derived in the Southwest USA. Most of the identified genes such as the heat shock proteins have been described as responsive to drought and heat in other plant species. Microarray analysis was used to identify drought-responsive genes that might confer this cotton genotype with an improved tolerance to drought stress. Leaves from cotton plants watered or exposed to drought stress were used for RNA extraction and generarion of cRNA probes for hybridization of Affymetrix microarrays. Microarray technology was used to identify drought-responsive genes in cotton to assist in molecular breeding program. The supplementary file 'GSE18253_differentially_expressed.txt' lists the differentially expressed genes.
Project description:In many potato cultivation regions, production is constrained by abiotic stresses such as drought and high temperatures which are often present in combination. We aimed to identify key mechanisms and processes underlying single and combined abiotic stress tolerance by a comparative analysis of tolerant and susceptible cultivars. Physiological data supported cultivars Desiree and Unica as being abiotic stress tolerant, while Agria and Russett Burbank were stress susceptible. This was indicated by the stronger impact of abiotic stress on photosynthetic carbon assimilation in the susceptible cultivars. Similarly, susceptible cultivars exhibited a lower leaf transpiration rate following stress, particularly combined heat and drought stress. Transcript profiles using microarrays were highly divergent both between genotypes and following the application of stress treatments. However, relatively few transcripts or metabolites exhibited genotype specific responses to abiotic stress treatment. Furthermore, apart from a decrease in the abundance of transcripts associated with PSII, particularly the light harvesting complex in both Desiree and Unica, there were very few changes that were consistent across stress susceptible or stress tolerant genotypes following stress treatment.