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.
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.
Project description:A heat and drought tolerant rice cultivar (N22) was grown in the field under control and drought conditions during the dry season in 2013. Drought was applied during early grain filling and resulted in simultaneous heat stress, leading to reduced grain yield and quality. Total RNA was extracted from developing seeds under stress and control (fully flooded) conditions and RNA-seq analysis was performed. These samples are a part of a bigger experiment analysing the responses of three contrasting rice cultivars (N22, Dular, Anjali) to combined heat and drought stress including different organs (developing seeds, flag leaves, flowering spikelets) and developmental stages (early grain filling, flowering) at the transcriptomic level.
Project description:Functional characterization of transgenic Arabidopsis plants constitutively expressing CAHB12 resulted in increased tolerance to drought stress, during distinct developmental stages, and increased tolerance to salt stress during seed germination. An insight into the gene set modulated by the ectopic expression of CAHB12 ectopic expression was provided by parallel sequencing (RNA-Seq) of high molecular weight and small RNA fractions. Classical drought responsive genes were mostly repressed, suggesting that other mechanisms are likely contributing to the tolerant phenotype exhibited by CAHB12-ectopically expressing plants, such as the pathway signaled by heat shock proteins and heat shock transcription factors.
Project description:Heat shock factors (Hsfs) are known to regulate heat and drought stress response by controlling the expression of heat shock proteins and oxidative stress responsive genes. Loss-of-function of OsHSFA2e gene resulted in increased sensitivity of rice plants to drought and heat stress. To identify the targets of OsHSFA2e and dissect the stress response pathway regulated by it, we performed transcriptome profiling of Oshsfa2e mutant plants under drought stress as well as well-watered conditions by RNA-sequencing.
Project description:Heat stress and extreme temperatures negatively affect plant development by disrupting regular cellular and biochemical functions, ultimately leading to reduced crop production. Recently, our group has shown through physiological experiments that miR156 overexpression resulted in an improved alfalfa response to heat stress. To further expand the scope of miR156 research, we employed a label-free quantification based quantitative proteomics approach to explore the effects of heat stress on protein levels in miR156OE alfalfa. Our major objective was to identify miR156-regulated gene products with differentially altered abundance under heat stress in alfalfa.
Project description:Alfalfa is the most produced perennial forage crop in Canada. Drought stress is a major form of abiotic stress, affecting its productivity and annual yield. A small RNA, miR156, plays a major role in drought tolerance by downregulating downstream SPL genes, but its effects at the proteome level are unknown. In this study, the protein level perturbations of miR156 overexpression (A8) and empty vector (EV) control genotypes were compared under drought stress. Using label-free quantification, 3,000 protein groups were identified, of which 68 were upregulated in A8 and 84 were downregulated relative to EV under control conditions. Conversely, under drought stress, 610 proteins were upregulated and only 52 proteins were downregulated in A8 relative to EV. Functional analysis using PlantRegMap showed that the enriched proteins are likely involved in biological and molecular processes including antioxidant response, response to stress, signal transduction and biosynthesis of secondary metabolites. These proteins/pathways might be involved in the enhancement of drought stress tolerance mediated by miR156. Protein groups related to signaling, such as MAP kinase, calcium-dependent protein kinase, protein phosphatase 2C, and transcriptional regulators including bZIP and zinc finger proteins were found to be differentially expressed when a search was conducted against a drought stress gene database. The proteomic dataset was validated by immunoblotting of selected proteins. The results of this study provide a better understanding and insight into the role of miR156 in drought stress tolerance in alfalfa at the proteomic level.
Project description:Abstract: In order to understand the expression patterns of miRNAs in alfalfa under alkali stress, small RNA sequencing was performed on alfalfa roots at different time points under alkali stress, and miRNAs were identified and analyzed.
Project description:RNA sequencing was performed to investigate the the response mechanism of tomato response to drought stress. C2H2-type zinc finger proteins are classic and extensively studied members of the zinc finger family. C2H2-type zinc finger proteins participate in plant growth, development and stress responses. In this study, 99 C2H2-type zinc finger protein genes were identified and classified into four groups, and many functionally related cis-elements were identified. Differential C2H2-ZFP gene expression and specific responses were analyzed under drought, cold, salt and pathogen stresses based on RNA-Seq data. Thirty-two C2H2 genes were identified in response to multiple stresses. Seven, 3, 5, and 8 genes were specifically expressed under drought, cold, salt and pathogenic stresses, respectively. Five glycometabolism and sphingolipid-related, pathways and the endocytosis pathway were enriched by KEGG analysis. The results of this study represent a foundation for further study of the function of C2H2-type zinc finger proteins and will provide us with genetic resources for stress tolerance breeding.
Project description:Floral organs are extremely sensitive to stress during anthesis and lead to severe yield loss. Rice anthers and pollinated pistils of two cultivars with contrasting tolerance to heat and drought stress under variable conditions, including control, heat, combined heat and drought stress, were used to explore gene expression pattern in male and female reproductive organs during anthesis under control and stress conditions. More gene regulation was induced by combined drought and heat stress than heat in anthers of both cultivars. N22 showed less regulation under combined stress than Moroberekan. The overlap of regulated genes between two cultivars was rather low, indicated the distinct molecular stress responses. We used whole genome microarrays to explore gene expression pattern and molecular mechanisms in male and female reproductive organs during anthesis under control and stress conditions in two rice cultivars, sought to identify the key transcripts that play roles in inducing heat and drought tolerance during reproduction in rice.