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: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.
Project description:Although previous studies have addressed the possible benefits of arbuscular mycorrhizal (AM) symbiosis for rice plants under salinity, the underlying molecular mechanisms are still unclear. Here, we showed that rice colonized with AM fungi had better growth performance and higher K+/Na+ ratio under salt stress. Differentially expressed genes (DEGs) responding to AM symbiosis especially under salt stress were obtained from RNA sequencing. AM-regulated DEGs in cell wall modification and peroxidases categories were mainly upregulated in shoots, suggesting AM symbiosis might assist in relaxing the cell wall and scavenging reactive oxygen species (ROS). AM symbiosis indeed improved ROS scavenging capacity in rice shoots under salt stress. In addition, genes involved in Calvin cycle and terpenoid synthesis were enhanced by AM symbiosis in shoots and roots under salt stress, respectively. AM-upregulated cation transporters and aquaporin in both shoots and roots were highlighted. Strikingly, “protein tyrosine kinase activity” subcategory was the most significantly over-represented GO term among all AM-upregulated and downregulated DEGs in both shoots and roots, highlighting the importance of kinase on AM-enhanced salinity tolerance. Overall, our results from the transcriptomic analyses indicate that AM symbiosis uses a multipronged approach to help plants achieve salt stress tolerance.
Project description:Ascophyllum nodosum extract induced salinity tolerance in Arabidopsis thaliana We used microarrays to detail the global programme of gene expression underlying ANE mediated salinity tolerance in the Arabidopsis thaliana
Project description:Lipopolysaccharide is a Microbe Associated Molecular Pattern (MAMP) that is known to induce defense responses in plants. We have shown that treatment of rice leaves with Xoo LPS induces callose deposition, reactive oxygen production and enhances resistance against subsequent infection by the pathogen. We have performed transcriptional profiling of rice leaves that are treated with Xoo LPS to identify differentially expressed genes. Xoo LPS was injected into mid-veins of rice leaves and RNA was isolated 15 hours later.
Project description:High light stress in subtropical and tropical regions strongly limits agricultural production due to photo-oxidative damage, decreased growth and yield. Here, we investigated whether beneficial microbes can protect plants under high light stress. We show that Enterobacter sp. SA187 (SA187) assists Arabidopsis in maintaining growth under high light stress, reducing the accumulation of reactive oxygen species (ROS) and maintaining photosynthesis. Under high light stress, SA187 induces dynamic transcriptional changes related to a fortified iron metabolism and redox system in Arabidopsis. A genetic analysis shows that SA187-induced plant high light stress tolerance is mediated by ethylene signaling via the transcription factor EIN3 to enhance iron metabolism. In summary, we show that Arabidopsis interaction with SA187 results in sustained photosynthesis under high light stress suggesting that beneficial microbes could be effective and cheap means for enhancing high light stress tolerance in crops.
Project description:Lipopolysaccharide is a Microbe Associated Molecular Pattern (MAMP) that is known to induce defense responses in plants. We have shown that treatment of rice leaves with Xoo LPS induces callose deposition, reactive oxygen production and enhances resistance against subsequent infection by the pathogen. We have performed transcriptional profiling of rice leaves that are treated with Xoo LPS to identify differentially expressed genes.
Project description:Grapevine is a plant of agronomic interest, which is able to cope with several stresses: heat, drought, and hypoxia, among others. A recent study showed very low oxygen levels inside grape berries, linked to ethanol content. Other studies have established the link between ethanol and tolerance to various stresses: heat stress, drought, and high salinity. The causes of such tolerance induced by ethanol are not well understood. In our study, three-week-old Gamay calli were characterised for their endogenous O2 levels (78 ± 43 µM at 2.1 mm inside the callus) and endogenous ethanol concentration (406 ± 2 µM). Subsequently, a transcriptomic study of these cells was conducted, at 6 and 24 hours post-treatment with 1 mM ethanol. After 6 hours post-treatment, ethanol addition led to 386 Differentially Expressed Genes (DEGs) compared to the controls. Analyses of the gene classes modulated by ethanol showed that many genes involved in heat response were up-regulated, notably the small Heat Shock Proteins (sHSP). Next, we showed that grape cells primed with ethanol experienced less pigment leakage due to heat stress compared to the controls. This result was further supported by a similar observation in Arabidopsis seedlings, for which heat stress-induced electrolyte leakage was reduced by ethanol priming. his study confirms previous observations regarding the beneficial role of ethanol priming in protecting plants against heat stress and provides a comprehensive set of RNA-seq data to further decipher the mechanisms involved in such adaptation. The small heat shock proteins seem involved in this chemical priming response.