Project description:In this study, proteomics was used to sequence the salt stress treatment group and the control group of Medicago sativa and Medicago truncatula. The aim was to discover the kegg pathway of the two alfalfa varieties under salt stress, which was of great significance to the exploration of the salt tolerance mechanism of alfalfa.
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:Enterobacter sp. SA187 is a plant growth-promoting bacterium (PGPB) that promotes growth of the crop plant alfalfa under saline irrigation and desert farming conditions. SA187 also enhances salt tolerance of the model plant Arabidopsis thaliana under in vitro conditions. In the present study, we used a transcriptomic approach to elucidate the mechanisms underlying plant growth promotion by SA187 under salt stress. Compared to free-living SA187, a massive metabolic reprogramming of SA187 occurs upon association with Arabidopsis. This effect was largely independent of the plant growth condition (non-salt or salt stress). Our data revealed pronounced changes in gene expression of proteins involved in cell signaling, chemotaxis, flagella biosynthesis, quorum sensing and biofilm formation. Also, upon plant interaction, a complete reprograming of nutrients acquisition and the central carbon metabolism of SA187 was observed. Moreover, in accordance with the previously identified role of bacterially produced 2-keto-4-methylthiobutyric acid (KMBA) in mediating salt stress tolerance, the sulfur metabolism of SA187 was strongly induced. Overall, our results give a deep insight into the metabolic and signaling pathways involved in the transition from free-living to a plant-associated PGPB life style of SA187.
Project description:Recent studies have shown that several plant species require microbial associations for stress tolerance and survival. In this work, we show that the desert endophytic bacterium Enterobacter sp. SA187 enhances yield and biomass of alfalfa in field trials, revealing a high potential for improving desert agriculture. To understand the underlying molecular mechanisms, we studied SA187 interaction with Arabidopsis thaliana. SA187 colonized surface and inner tissues of Arabidopsis roots and shoots and conferred tolerance to salt and osmotic stresses. Transcriptome, genetic and pharmacological studies revealed that the ethylene signaling pathway plays a key role in mediating SA187-triggered abiotic stress tolerance to plants. While plant ethylene production is not required, our data suggest that SA187 induces abiotic stress tolerance by bacterial production of 2-keto-4-methylthiobutyric acid (KMBA), known be converted into ethylene in planta. These results reveal a part of the complex molecular communication process during beneficial plant-microbe interactions and unravel an important role of ethylene in protecting plants under abiotic stress conditions.
Project description:The dataset presented here is about global protein levels in a common alfalfa cultivar, Medicago sativa L. (cv. Nongjing No 1), with exposure to 200mM salt stress for 14 days using parallel proteomics monitoring (PRM) based targeted proteomics approach.