Stress responsive gene expression in rice cultivars
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ABSTRACT: In this study, we aim to present a global view of transcriptome dynamics in different rice cultivars (IR64, Nagina 22 and Pokkali) under control and stress conditions. More than 50 million high quality reads were obtained for each tissue sample using Illumina platform. Reference-based assembly was performed for each rice cultivar. The transcriptome dynamics was studied by differential gene expression analyses between stress treatment and control sample. We collected seedlings of three rice cultivars subjected to control (kept in water), desiccation (transferred on folds of tissue paper) and salinity (transferred to beaker containing 200 mM NaCl solution) treatments. Total RNA isolated from these tissue samples was subjected to Illumina sequencing. The sequence data was further filtered using NGS QC Toolkit to obtain high-quality reads. The filtered reads were mapped to Japonica reference genome using Tophat software. Cufflinks was used for reference-based assembly and differential gene expression was studied using cuffdiff software. The differentially expressed genes during various abiotic stress conditions were identified.
Project description:In this study, we aim to generate genome-scale DNA methylation profiles at single-base resolution in different rice cultivars (IR64, Nagina 22 and Pokkali) under control and stress conditions. Using high-throughput whole genome bisulfite Sequencing, we generated DNA methylation maps covering the vast majority of cytosines in the rice genome. More than 152 million high quality reads were obtained for each tissue sample using Illumina platform. We discovered extensive DNA methylation in rice cultivars, identified the context and level of methylation at each site.Numerous differentially methylated regions (DMRs) among different cultivars under control and stress conditions were identified and many of them were associated with differential gene expression. The high resolution methylome maps of different rice genotypes and differentially methylated regions will serve as reference for understanding the epigenetic regulation of stress responses in plants. Whole genome bisulfite sequencing of seven control/stressed samples from three rice cultivars (IR64, N22 and Pokkali)
Project description:In this study, we aim to present a global view of transcriptome dynamics during various abiotic stresses in chickpea. We generated about 252 million high-quality reads from eight libraries (control, desiccation, salinity and cold stress samples for roots and shoots) using Illumina high-throughput sequencing GAII platform. We mapped the reads to the desi chickpea genome for estimation of their transcript abundance in different tissue samples. The transcriptome dynamics was studied by differential gene expression analyses between stress treatment and control sample. We collected different tissue samples (root and shoot tissues of 10-day-old seedlings subjected to control (kept in water), desiccation (transferred on folds of tissue paper), salinity (transferred to beaker containing 150 mM NaCl solution) and cold (kept in water at 4 M-BM-1 1M-BM-0C) stress for 5 h. Total RNA isolated from these tissue samples was subjected to Illumina sequencing. The sequenced data was further filtered using NGS QC Toolkit to obtain high-quality reads. The filtered reads were mapped to annotated chickpea genome using TopHat and fragments per exon kilobase per million (FPKM) was calculated using Cufflinks software for each gene in all the sample to measure their gene expression. Differential expression analysis was performed using Cuffdiff software. The differentially expressed genes during various abiotic stress conditions were identified.
Project description:In this study, we sequenced small RNA content from three different rice cultivars employing Illumina technology. More than 15 million reads were generated using Illumina high-throughput sequencing platform. After pre-processing, distinct small RNA sequences were identified for each rice cultivars. We collected seedlings of different rice cultivars and total RNA isolated was subjected to Illumina sequencing. The sequenced data was further filtered using NGS QC Toolkit to obtain high-quality reads. The filtered reads were pre-processed using modified perl script provided in the miRTools software. After quality control, the identical reads were collapsed into a unique read and read count for each sequence was recorded. All the filtered unique reads from each sample were mapped on the rice genome to find their location.
Project description:In this study, we aim to present a global view of transcriptome dynamics in different rice cultivars (IR64, Nagina 22 and Pokkali) under control and stress conditions. More than 50 million high quality reads were obtained for each tissue sample using Illumina platform. Reference-based assembly was performed for each rice cultivar. The transcriptome dynamics was studied by differential gene expression analyses between stress treatment and control sample.
Project description:Purpose: To study the differential gene expression by comparing resistant and susceptible rice cultivars against the rice blast fungus M. Oryzae. Methods: Rice leaves were collected after M. Oryzae (MO36) infection from resistant and susceptible cultivars, preserved on deep freezer on -80O C frozen on liquid nitrogen, Total RNA from rice plant tissues was extracted using RNeasy Plant Mini Kit (Qiagen) by following manufacturer protocol. RNA libraries were prepared for sequencing using standard Illumina protocols. Results: Around 35 million pairs of filtered 150 base paired reads were obtained for each biological sample. These reads were mapped against RGAP7 using reference assembly tool of CLC Genomics Workbench. The mapped read data was summarised in to a matrix for each sample. count data was compared between the samples to identify the differentially expressed genes. genes were further filtered based on fold change, p value and FDR p value. The count data was further statistically analysed using Kal's Z test integrated into CGWB. Genes exhibiting 3 fold change and FDR p value <0.05 were filtered as either up regulated or down regulated gene. we obtained 7577 and 4290 significant (FDR adjusted p value ≤0.05) differentially expressed locus id in the resistant and susceptible rice cultivars, respectively . The number of significant DEL with fold change value greater and less than 3 were 3523 upregulated 4054 downregulated and 2190 upregulated & 2100 downregulated in resistance and susceptible cultivars, respectively. 2-way and and 4-way upregulated and downregulated gene comparisions was carried out. To identify the changes in biological process and molecular function the pathway and gene set enrichment analysis was performed in resistant BR2655 and susceptible HR12 rice cultivars. Conclusions: This study represents the first transcriptome analysis of resistant BR2655 and susceptible HR12 upon M.oryzae infection, generated by RNA-seq technology. This transcriptome analysis further helps to understand the differential gene expression analysis response to the M.oryzae. And candidate genes which are involved in triggering defense mechanism in rice plants. Further it helps to understand the mechanism of activating a cascade of defense responses in resistant and susceptible plants.
Project description:In this study, we aim to generate genome-scale DNA methylation profiles at single-base resolution in different rice cultivars (IR64, Nagina 22 and Pokkali) under control and stress conditions. Using high-throughput whole genome bisulfite Sequencing, we generated DNA methylation maps covering the vast majority of cytosines in the rice genome. More than 152 million high quality reads were obtained for each tissue sample using Illumina platform. We discovered extensive DNA methylation in rice cultivars, identified the context and level of methylation at each site.Numerous differentially methylated regions (DMRs) among different cultivars under control and stress conditions were identified and many of them were associated with differential gene expression. The high resolution methylome maps of different rice genotypes and differentially methylated regions will serve as reference for understanding the epigenetic regulation of stress responses in plants.
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:Oilseed mustard, Brassica juncea, exhibits high levels of genetic variability for salinity tolerance. To obtain the global view of transcriptome and investigate the molecular basis of salinity tolerance in a salt-tolerant variety CS52 of B. juncea, we performed transcriptome sequencing of control and salt-stressed seedlings. De novo assembly of 184 million high-quality paired-end reads yielded 42,327 unique transcripts longer than 300 bp with RPKM ≥1. When compared with non-redundant proteins, we could annotate 67% unigenes obtained in our study. Based on the mapping to expressed sequence tags (ESTs), 52.6% unigenes are novel compared to EST data available for B. juncea and constituent genomes. Differential expression analysis revealed altered expression of 1469 unigenes in response to salinity stress. Of these, 587, mainly associated with ROS detoxification, sulfur assimilation and calcium signaling pathways, are up regulated. Notable of these is RSA1 (SHORT ROOT IN SALT MEDIUM 1) INTERACTING TRANSCRIPTION FACTOR 1 (RITF1) homolog up regulated by >100 folds in response to stress. RITF1, encoding a bHLH transcription factor, is a positive regulator of SOS1 and several key genes involved in scavenging of salt stress-induced reactive oxygen species (ROS). Further, we performed comparative expression profiling of key genes implicated in ion homeostasis and sequestration (SOS1, SOS2, SOS3, ENH1, NHX1), calcium sensing pathway (RITF1) and ROS detoxification in contrasting cultivars, B. juncea and B. nigra, for salinity tolerance. The results revealed higher transcript accumulation of most of these genes in B. juncea var. CS52 compared to salt-sensitive cultivar even under normal growth conditions. Together, these findings reveal key pathways and signaling components that contribute to salinity tolerance in B. juncea var. CS52. We report transcriptome sequencing of two-weeks-old seedlings of B. juncea var. CS52 under normal growth conditions (CTRL) and in response to salinity stress (SS) using Illumina paired-end sequencing
Project description:Rice has developed several morphological and physiological strategies to adapt to phosphate starvation stress. In order to elucidate the molecular bases of response due to phosphate stress particularly the transcriptional profile of genotypes with variation in tolerance to phosphate starvation, we analyzed the gene expression profiles of 3 japonica rice cultivars and an indica cultivar with different levels of tolerance to phosphate starvation using the RNA-Seq method. We constructed a total of 48 libraries corresponding to root and shoot of the 4 cultivars for control (0 d) and âP treatment (22 d) with three biological replicates for root and shoot samples in each cultivar. Approximately 254 million sequenced tags were mapped onto the reference rice genome sequence (IRGSP1.0) and an average of about 5,000 transcripts in each genotype were found to be responsive to Pi-starvation. Comparative analysis of the responsive transcripts revealed an overall similarity in the transcriptome signatures resulting from phosphate starvation as well as distinct differences that distinguish the degree of tolerance among the 4 cultivars. We elucidated a set of core responsive transcripts commonly expressed in both root and shoot with different levels of expression reflecting variation as well genotype specificity in tolerance to Pi-starvation. De novo assembly of unmapped reads generated a large set of sequence assemblies that represent potential new transcripts that may be involved in tolerance to phosphate deficiency. Characterization of 88 assemblies unaligned in the reference genome revealed several dozen transcripts which correspond to plant ESTs. This study provides an overview of the diversity in response to P-starvation stress that can be used to identify the major genes for improving Pi acquisition and utilization in rice and other cereal crops. Note: Samples in DRA were assigned the same sample accession. This is incorrect as there are different samples, hence âSource Nameâ was replaced with new values. Comment[ENA_SAMPLE] contains the original DRA sample accessions.
Project description:The approval of genetically modified (GM) crops is preceded by years of intensive research to demonstrate safety to humans and environment. We recently showed that in vitro culture stress is the major factor influencing proteomic differences of GM vs. non-GM plants. This made us question the number of generations needed to erase such memory. We also wondered about the relevance of alterations promoted by transgenesis as compared to environment-induced ones. Here we followed three rice lines (1-control- C, 1-transgenic- Ta and 1-negative segregant- NSb) throughout eight generations after transgenesis, and further analyzed their response to salinity stress on the F6 generation. Three pools of 10 whole fifteen days-old rice seedlings (Oryza sativa L. ssp. japonica cv. Nipponbare) were selected from each line at F4, F6 and F8 generations. Because salinity stress was imposed on half of the seedlings (C, Ta and NSb) in F6 generation, from this generation onwards we worked with six rice lines (C, Csalt, Ta, Tasalt, NSb, NSbsalt).