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.
2023-05-08 | GSE231697 | GEO
Project description:Small RNA-seq for alfalfa roots under alkaline stress
Project description:Abstract: In order to clarify the response mechanism of alfalfa under alkali stress, the transcriptome of roots was sequenced at different time points after stress and the expression patterns of all genes were analyzed.
Project description:Alkaline salts (e.g., NaHCO3 and Na2CO3) causes more severe morphological and physiological damage to plants than neutral salts (e.g., NaCl and Na2SO4) due to differences in pH. The mechanism by which plants respond to alkali stress is not fully understood, especially in plants having symbotic relationships such as alfalfa (Medicago sativa L.). Therefore, a study was designed to evaluate the metabolic response of the root-nodule symbiosis in alfalfa under alkali stress using comparative metabolomics. Rhizobium-nodulized (RI group) and non-nodulized (NI group) alfalfa roots were treated with 200 mmol/L NaHCO3 and, roots samples were analyzed for malondialdehydyde (MDA), proline, glutathione (GSH), superoxide dismutase (SOD), and peroxidase (POD) content. Additionally, metabolite profiling was conducted using gas chromatography combined with time-of-flight mass spectrometry (GC/TOF-MS). Phenotypically, the RI alfalfa exhibited a greater resistance to alkali stress than the NI plants examined. Physiological analysis and metabolic profiling revealed that RI plants accumulated more antioxidants (SOD, POD, GSH), osmolytes (sugar, glycols, proline), organic acids (succinic acid, fumaric acid, and alpha-ketoglutaric acid), and metabolites that are involved in nitrogen fixation. Our pairwise metabolomics comparisons revealed that RI alfalfa plants exhibited a distinct metabolic profile associated with alkali putative tolerance relative to NI alfalfa plants. Data provide new information about the relationship between non-nodulized, rhizobium-nodulized alfalfa and alkali resistance.
Project description:Plant roots are the primary site of perception and injury for saline-alkaline stress. The current knowledge of the saline-alkaline stress transcriptome is most focused on salt (NaCl) stress. Only a little alkaline (NaHCO3) stress transcriptome is limited to one time point after stress. Time-course analysis and comparative investigation on roots in the alkaline stress condition are needed to understand the gene response networks that are subject to alkaline tolerance. We used microarrays to detail the global programme of gene expression underlying NaHCO3 treatment and identified distinct classes of regulated genes during this process.
Project description:Plant roots are the primary site of perception and injury for saline-alkaline stress. The current knowledge of the saline-alkaline stress transcriptome is most focused on salt (NaCl) stress. Only a little alkaline (NaHCO3) stress transcriptome is limited to one time point after stress. Time-course analysis and comparative investigation on roots in the alkaline stress condition are needed to understand the gene response networks that are subject to alkaline tolerance. We used microarrays to detail the global programme of gene expression underlying NaHCO3 treatment and identified distinct classes of regulated genes during this process. Three week old Glycine soja seedling roots from 3cm root apex were harvested in two independent biological replicates after 0, 0.5, 1, 3, 6, 12 and 24h treatment with 50mmol/L NaHCO3 stress for RNA extraction and hybridization on Affymetrix microarrays. To minimize biological variance, roots from three plants originating from the same experiment, condition and cultivar was pooled.
Project description:12plex_medicago_2014_02 - nar nodule vs root transcriptome - which are the genes differentially expressed in alfalfa spontaneous (non rhizobium-infected) nodules vs. control roots? - biological material: aeroponically grown cuttings of a Medicago sativa (alfalfa) accession that produces empty nodules when nitrogen-starved. Samples for transcriptome comparison: isolated NAR nodules (10 days post N-starvation) vs. roots of the same plants (pools of 3 roots).
Project description:Alfalfa (Medicago sativa L.) is a forage legume with significant agricultural value worldwide. MicroRNAs (miRNAs) are key components of post-transcriptional gene regulation and essentially control almost all aspect of plant growth and development. Although miRNAs have been reported from alfalfa but their expression profiles in different tissues and novel miRNAs as well as their targets have not been confirmed in this plant species. Therefore, we sequenced small RNAs in whole plantlets, shoots and roots of three different alfalfa genotypes (Altet-4, NECS-141 and NF08ALF06) to identify tissue-specific profiles. After comprehensive analysis using bioinformatics methods, we have identified 100 miRNA families, of which 21 belongs to the highly conserved families whereas the remaining 79 families are conserved between M. truncatula and M. sativa. The profiles of the six highly expressed conserved miRNA families (miR156, 159, 166, 319, 396, 398,) were relatively similar between the plantlets, roots and shoots of three genotypes. Contrastingly, the differenecs were robust between shoots and roots for miR160 and miR408 levels, which were low in roots compared to shoots. The study also has identified 17 novel miRNAs that also differed in their abundanecs between tissues of the alfalfa genotypes. Additionally, we have generated and analyzed the degradome libraries from three alfalfa genotypes that has confirmed 69 genes as targets for 31 miRNA families in alfalfa. The identification of conserved and novel miRNAs as well as their targets in different tissues of three genotypes not only enhanced our understanding of miRNA-mediated gene regulation in alfalfa but could also be useful for practical applications in alfalfa as well as related legume species.
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.