Olive (Olea europaea) cv.Kalamon: Control vs Salt-treated
Ontology highlight
ABSTRACT: A transcriptomics approach was used as a tool to unravel gene regulatory network underlying salinity response in a salt-tolerant olive cultivar (cv. Kalamon) by simulating as much as possible olive growing conditions in the field. A 135 day long salinity experiment was conducted using one year old trees exposed to NaCl stress for 90 days followed by 45 days of post-stress period. Total RNA was extracted from the root samples after 15, 45 and 90 days of NaCl-treated and un-treated olive trees as well as after 15 and 45 days of post-treatment period and used for microarray hybridizations using a loop design. Hierarchical clustering of differentially expressed transcripts revealed two major, distinct clusters. Despite the limited number of probe set, a transcriptional regulatory networks was constructed for the salt-tolerant cultivar.
Project description:A comparative transcriptomics approach was used as a tool to unravel gene regulatory networks underlying salinity response in olive trees by simulating as much as possible olive growing conditions in the field. Specifically, we investigated the genotype-dependent differences in the transcriptome response of two olive cultivars, a salt tolerant and a salt sensitive. A 135 day long comparative salinity experiment was conducted using one year old trees exposed to NaCl stress for 90 days followed by 45 days of post-stress period. Total RNA was extracted from the root samples after 15, 45 and 90 days of NaCl-treated and un-treated olive trees as well as after 15 and 45 days of post-treatment period and used for microarray hybridizations using a loop design. Hierarchical clustering of differentially expressed transcripts revealed two major, distinct clusters for each cultivar. Despite the limited number of probe set, transcriptional regulatory networks were constructed for the salt-tolerant and salt-sensitive cultivar. The comparison of the salt responsive transcriptional regulatory networks in olive with those reported for Arabidopsis suggests that a tree species might respond in a similar to Arabidopsis way at the transcriptome level under salinity stress.
Project description:A comparative transcriptomics approach was used as a tool to unravel gene regulatory networks underlying salinity response in olive trees by simulating as much as possible olive growing conditions in the field. Specifically, we investigated the genotype-dependent differences in the transcriptome response of two olive cultivars, a salt tolerant and a salt sensitive. A 135 day long comparative salinity experiment was conducted using one year old trees exposed to NaCl stress for 90 days followed by 45 days of post-stress period. Total RNA was extracted from the root samples after 15, 45 and 90 days of NaCl-treated and un-treated olive trees as well as after 15 and 45 days of post-treatment period and used for microarray hybridizations using a loop design. Hierarchical clustering of differentially expressed transcripts revealed two major, distinct clusters for each cultivar. Despite the limited number of probe set, transcriptional regulatory networks were constructed for the salt-tolerant and salt-sensitive cultivar. The comparison of the salt responsive transcriptional regulatory networks in olive with those reported for Arabidopsis suggests that a tree species might respond in a similar to Arabidopsis way at the transcriptome level under salinity stress. Five experimental time-points were analyzed: 15days stress, 45days stress, 90days stress, 15days post-stress and 45days post-stress. In each timepoint treated and untreated (control) samples were obtained. Dye swap hybridizations and 4 biological replicates were performed for each treatment/timepoint in a loop design experimental setup. Each sample included three spot replicates.
Project description:A transcriptomics approach was used as a tool to unravel gene regulatory network underlying salinity response in a salt-tolerant olive cultivar (cv. Kalamon) by simulating as much as possible olive growing conditions in the field. A 135 day long salinity experiment was conducted using one year old trees exposed to NaCl stress for 90 days followed by 45 days of post-stress period. Total RNA was extracted from the root samples after 15, 45 and 90 days of NaCl-treated and un-treated olive trees as well as after 15 and 45 days of post-treatment period and used for microarray hybridizations using a loop design. Hierarchical clustering of differentially expressed transcripts revealed two major, distinct clusters. Despite the limited number of probe set, a transcriptional regulatory networks was constructed for the salt-tolerant cultivar. Five experimental time-points were analyzed: 15days stress, 45days stress, 90days stress, 15days post-stress and 45days post-stress. In each timepoint treated and untreated (control) samples were obtained. Dye swap hybridizations and 4 biological replicates were performed for each treatment/timepoint in a loop design experimental setup. Low-quality arrays were not included in the data analysis (36 arrays/samples submitted). Each sample included three spot replicates.
Project description:Most physiological and molecular mechanisms of salinity stress are researched based on salt shock conditions. However, salt shock doesn’t occur in agricultural practice or natural ecosystem. In the fields, salts accumulate gradually through high salt or sodium irrigation water and poor managements that allow ground water to rise to soil surface. Therefore, it is more reasonable to research salinity stress in a mild way (stepwise salt addition). The objective of this study is to select marker genes to differentiate between salt shock (Phase 0) and salt stress (Phase 1). Three replicates were used for all RNA-Seq experiments conducted on control, Phase 0 and Phase 1 samples in Arabidopsis thaliana. Phase 0 samples (rosette leaves) were harvested 1 hour later from 105 mM NaCl salt shock treatment; Phase 1 samples (rosette leaves) were harvested 2 days later after reaching 90 mM NaCl by a stepwise addition (15 mM NaCl per day).
Project description:RNA sequencing of salinity tolerant Arabidopsis thaliana mutants expressing zinc finger artificial transcription factors (ZF-ATFs), with and without salt treatment (0 mM and 75 mM NaCl).
Project description:Sprobolus virginicus is a halophytic C4 grass found in worldwide from tropical to warm temperate regions. A Japanese genotype showed a salinity tolerance up to 1,500 mM NaCl, a three-fold higher concentration than seawater salinity. To identify key genes involved in the regulation of salt tolerance in S. virginicus, random cDNA libraries were constructed from salt-treated leaves, and were introduced into Arabidopsis for salt tolerant plant screening. Eight independent transgenic lines were found to be more salt tolerant than wild type from the screen of 3011 lines on the medium containing 175 mM NaCl. Among the selected lines, two contained cDNAs encoding glycine-rich RNA-binding proteins (GRPs). To identify transcriptomic change in the GRP-transgenic line, we performed microarray analysis of the transgenic line and WTunder salt stress.
Project description:To detect salt-tolerance-related miRNAs, comparative analysis of miRNA expression profiles was performed between the salt-tolerant and -sensitive cotton cultivars in control and salt-stressed conditions (treated with 300 mM NaCl for 24 h) using microRNA microarray Total RNA was extracted from (1) the seedling of salt-tolerant cotton cultivar in normal growth conditions, (2) the seedling of salt-tolerant cotton cultivar in salt-stressed growth conditions, (3) the seedling of salt-sensitive cotton cultivar in normal growth conditions, and (4) the seedling of salt-sensitive cotton cultivar in salt-stressed growth conditions. Then, the low-molecular-weight RNA (LMW-RNA) was isolated using the PEG solution precipitation method and used to hybridization.
Project description:Analysis of root gene expression of salt-tolerant genotypes FL478, Pokkali and IR63731, and salt-sensitive genotype IR29 under control and salinity-stressed conditions during vegetative growth. Results provide insight into the genetic basis of salt tolerance in indica rice. Experiment Overall Design: Seedlings were cultured in sand and irrigated with a nutrient solution for 22 d (salt-treated) and 30 d (control) after germination, respectively. Salinity treatment was applied by adding NaCl and CaCl2 (5:1 molar concentration) in two steps over a period of 3 days (final electrical conductivity: 7.4 dS m-1) to prevent osmotic shock. All plants were harvested on day 30.
Project description:Soil salinity is a major production constrain for agricultural crops, especially in Oryza sativa (rice). Analyzing physiological effect and molecular mechanism under salt stress is key for developing stress-tolerant plants. Roots system has a major role in coping with the osmotic change impacted by salinity and few salt-stress-related transcriptome studies in rice have been previously reported. However, transcriptome data sets using rice roots grown in soil condition are more relevant for further applications, but have not yet been available. The present work analyzed rice root and shoot physiological characteristics in response to salt stress using 250 mM NaCl for different timepoints. Subsequently, we identified that 5 day treatment is critical timepoint for stress response in the specific experimental design. We then generated RNA-Seq-based transcriptome data set with rice roots treated with 250 mM NaCl for 5 days along with untreated controls in soil condition using rice japonica cultivar Chilbo. We identified 447 upregulated genes under salt stress with more than fourfold changes (p value < 0.05, FDR < 0.05) and used qRT-PCR for six genes to confirm their salt-dependent induction patterns. GO-enrichment analysis indicated that carbohydrate and amino-acid metabolic process are significantly affected by the salt stress. MapMan overview analysis indicated that secondary metabolite-related genes are induced under salt stress. Metabolites profiling analysis confirmed that phenolics and flavonoids accumulate in root under salt stress. We further constructed a functional network consisting of regulatory genes based on predicted protein–protein interactions, suggesting useful regulatory molecular network for future applications.
Project description:With the growing limitations on arable land, alfalfa (a widely cultivated, low-input forage) is now being selected to extend cultivation into saline lands for low-cost biofeedstock purposes. Here, minerals and transcriptome profiles were compared between two new salinity-tolerant North American alfalfa breeding populations and a more salinity-sensitive Western Canadian alfalfa population grown under hydroponic saline conditions. All three populations accumulated two-fold higher sodium in roots than shoots as a function of increased electrical conductivity. At least 50% of differentially expressed genes (p < 0.05) were down-regulated in the salt-sensitive population growing under high salinity, while remaining unchanged in the saline-tolerant populations. In particular, most reduction in transcript levels in the salt-sensitive population were observed in genes specifying cell wall structural components, lipids, secondary metabolism, auxin and ethylene hormones, development, transport, signalling, heat shock, proteolysis, pathogenesis-response, abiotic stress, RNA processing, and protein metabolism. Transcript diversity for transcription factors, protein modification, and protein degradation genes was also more strongly affected in salt-tolerant CW064027 than in salt-tolerant Bridgeview and salt-sensitive Rangelander, while both saline-tolerant populations showed more substantial up-regulation in redox-related genes and B-ZIP transcripts. The report highlights the first use of bulked genotypes as replicated samples to compare the transcriptomes of obligate out-cross breeding populations in alfalfa. Three lines of Alfalfa (salt-tolerant CW064027, salt-tolerant Bridgeview, salt-sensitive Rangelander) were grown on 3 different concentrations of salt. For each cultivar-salt condition, 3 biological replicates were collected for a total of 27 samples.