Project description:Improvement of freezing tolerance of red clover (Trifolium pratense L.) would increase its persistence under cold climate. In this study, we assessed the freezing tolerance and compared the proteome composition of non-acclimated and cold-acclimated plants of two initial cultivars of red clover: Endure (E-TF0) and Christie (C-TF0) and of populations issued from these cultivars after three (TF3) and four (TF4) cycles of phenotypic recurrent selection for superior freezing tolerance. Through this approach, we wanted to identify proteins that are associated with the improvement of freezing tolerance in red clover. Recurrent selection performed indoor is an effective approach to improve the freezing tolerance of red clover. Significant improvement of freezing tolerance by recurrent selection was associated with differential accumulation of a small number of cold-regulated proteins that may play an important role in the determination of the level of freezing tolerance.
Project description:Transcriptomes analysis of the petals from a red-flowered white clover mutant (red flowers) and its shade-treated counterpart (white flowers) grown under shaded conditions was performed using high-throughput sequencing. We obtained 121,626,564 and 130,577,944 clean reads in red-flowered mutant and treated counterpart, respectively. Of these clean reads, we respectively gained 125,350 and 99,638 unigene sequencces in two groups. As a result, a total of 157,964 unigenes were obtained with an average length of 728 bp and a median length of 1346 bp. These findings provideed insights into the expression profiles in red-flowered white clover mutant, and deepened our understanding of flower pigmentation in white clower.
Project description:White clover mosaic virus (WCMV) is a major pathogen of white clover (Trifolium repens L.), with significant effects on yield and persistence. Due to the absence of natural sources of WCMV resistance a transgenic strategy has been employed to produce plants constitutively expressing WCMV replicase gene derivatives, designed to inhibit the propagation of WCMV through an RNA silencing mechanism. A 12,000 feature oligonucleotide microarray has been used to identify global changes in host plant, in addition to virus genome-encoded gene expression associated with WCMV infection in non-transgenic and transgenic WCMV-resistant white clover. Pairwise comparison between the transcriptome of mock-inoculated non-transgenic and WCMV-inoculated transgenic plants provides clear evidence for substantial equivalence between these two genotype/treatments, and demonstrate the efficacy of the transgenic strategy. WCMV- inoculated non-transgenic plants exhibit elevated abundance of many virus-encoded, and host immune response-specific transcripts compared to the transgenic resistant plants or mock-inoculated non-transgenic plants. By contrast, relative to inoculated sensitive plants, the majority of significantly up-regulated genes in mock-inoculated non-transgenic plants or WCMV-inoculated transgenic plants are markers of healthy cellular function. These results, and the occurrence of levels of WCMV-encoded transcripts in inoculated transgenic plants equivalent to those in virus-free plants, confirm the validity of the transgenic RNA silencing approach.<br>
Project description:To investigate the mechanisms related to anti-ferroptotic effects of red clover extract, we performed differentially expressed genes analysis using data obtained from the RNA-seq of system xCT knockout mouse embryonic fibroblast cells.
Project description:This study presents a global transcriptional analysis of the cold shock response of Shewanella oneidensis MR-1 after a temperature downshift from 30 to 8 or 15oC based on time-series microarray experiments. More than 700 genes were found to be significantly affected (p < 0.05) upon cold shock challenge, especially at 8oC. The temporal gene expression patterns of the classical cold-shock genes varied and only some of them, most notably so1648 and so2787, were differentially regulated in response to temperature downshift. The global response of S. oneidensis to cold shock was also characterized by the up-regulation of genes encoding membrane proteins, DNA metabolism and translation apparatus components, metabolic proteins, regulatory proteins, and hypothetical proteins. Most of the metabolic proteins affected are involved in catalytic processes that generate NADH or NADPH. Keywords: time course, stress response
Project description:Knowledge about molecular mechanisms underlying cold and freezing stress responses in perennial ryegrass is scarce. The current study aims to study cold and freezing stress responses of perennial ryegrass genotypes with contrasting cold tolerances. A panel of 160 genotypes were screened for cold tolerances based on electrolyte leakage % measured after 24 hrs at 12 °C and 24 hrs at 14 °C. Among them, 4 genotypes (2 low EL% and 2 high EL%) were selected to study cold and freezing stress responses. Plants were sampled at 6 timepoints; control (T1), beginning of cold acclimation (T2), 2 weeks into cold acclimation (T3), end of cold cold acclimation (T4), -5°C (T5), -10 °C (T6) followed by RNA extraction and sequencing.
Project description:The cold acclimation process is regulated by many factors like ambient temperature, day length, light intensity, or hormonal status. Experiments with plants grown under different light-quality conditions indicate that the plant response to cold is also a light-quality-dependent process. Here, the role of light quality in the cold response was studied in one-month-old Arabidopsis thaliana (Col‐0) plants exposed for one week to 4 °C at short‐day conditions under white (100 and 20 μmol m‐2s‐1), blue or red (20 μmol m‐2s‐1) light conditions. An upregulated expression of CBF1, an inhibition of photosynthesis, and an increase in membrane damage showed that blue light enhanced the effect of low temperature. Interestingly, cold-treated plants under blue and red light showed only limited freezing tolerance compared to white light cold-treated plants. Next, the specificity of the light quality signal in cold response was evaluated in Arabidopsis accessions originating from different and contrasting latitudes. In all but one Arabidopsis accessions, blue light increased the effect of cold on photosynthetic parameters and electrolyte leakage. This effect was not found for Ws-0, which lacks functional CRY2 protein, indicating its role in the cold response. Proteomics data confirmed significant differences between red and blue light treated plants at low temperature and showed that the cold response is highly accession specific. In general, blue light increased mainly the cold-stress related proteins and red light induced higher expression of chloroplast-related proteins, which correlated with higher photosynthetic parameters in red light cold-treated plants. Altogether, our data suggest that light modulates two distinct mechanisms during the cold treatment - red light driven cell function maintaining program and blue light activated specific cold response. The importance of mutual complementarity of these mechanisms was demonstrated by significantly higher freezing tolerance of cold-treated plants under white light.