Project description:We conducted microarray analysis to study comprehensive changes of gene expression profile under long-term low-temperature (LT) treatment and to identify other LT-responsive genes related with cold acclimation in seedling leaves and crown tissues (shoots containing apical meristems) of a synthetic hexaploid wheat line. The microarray analysis revealed marked up-regulation of a number of Cor/Lea genes and fructan biosynthesis-related genes under the long-term LT treatment. For validation of the microarray data, we selected four synthetic wheat lines, which contained the A and B genomes from a tetraploid wheat cultivar Langdon and the diverse D genomes originating from the different Ae. tauschii accessions, with distinct levels of freezing tolerance after cold acclimation. Quantitative RT-PCR analyses showed that the transcription accumulated levels of the Cor/Lea, CBF, and fructan biosynthesis-related genes were higher in more freezing-tolerant lines than those in the sensitive lines. The fructan biosynthesis pathway would be associated with cold acclimation to develop wheat freezing tolerance and related with diversity of the freezing tolerance level in addition to the CBF-mediated Cor/Lea expression pathway.
Project description:We conducted microarray analysis to study comprehensive changes of gene expression profile under long-term low-temperature (LT) treatment and to identify other LT-responsive genes related with cold acclimation in seedling leaves and crown tissues (shoots containing apical meristems) of a synthetic hexaploid wheat line. The microarray analysis revealed marked up-regulation of a number of Cor/Lea genes and fructan biosynthesis-related genes under the long-term LT treatment. For validation of the microarray data, we selected four synthetic wheat lines, which contained the A and B genomes from a tetraploid wheat cultivar Langdon and the diverse D genomes originating from the different Ae. tauschii accessions, with distinct levels of freezing tolerance after cold acclimation. Quantitative RT-PCR analyses showed that the transcription accumulated levels of the Cor/Lea, CBF, and fructan biosynthesis-related genes were higher in more freezing-tolerant lines than those in the sensitive lines. The fructan biosynthesis pathway would be associated with cold acclimation to develop wheat freezing tolerance and related with diversity of the freezing tolerance level in addition to the CBF-mediated Cor/Lea expression pathway. Expression patterns were compared between a synthetic wheat line which treated 24M-bM-^DM-^C and 4M-bM-^DM-^C. Total RNA samples were respectively isolated from leaves and crown tissues of the synthetic line grown at normal temperature for 3 weeks and then at 4M-BM-0C for 12 and 6 weeks. Two independent experiments were conducted in each exprement.
Project description:The aim of this study was to identify genetic mechanisms of tolerance to active de-acclimation in winter wheat by comparing four tolerant and four susceptible accessions (cultivars and advanced breeding lines). The plants were kept in controlled conditions. 21 days after sowing, the plants were cold acclimated (3 weeks, 4/2 °C, day/night temperature; photoperiod of 10/14 h). Cold acclimation was followed by 7 days of de-acclimating conditions, mimicking a mid-winter warm spell: 12/5°C, day/night temperature; photoperiod of 10/14 h). The fragments of leaves were sampled in three biological replicates (three different plants of the same accession) in three timepoints: just before cold-acclimation (CA-0), after cold-acclimation (CA-21), and after de-acclimation (DA-28). Total RNA samples were sequenced on Illumina NovaSeq 6000 platform in PE150 bp mode. Differences in expression for a given accession were tested between all time-points, averaging the results for three biological replicates. It has been confirmed that active de-acclimation is not simply the inverse of cold acclimation, and that susceptible forms show significantly more changes in expression as a result of de-acclimation than tolerant forms. This provides further support for the hypothesis that tolerance to de-acclimation consists mainly of the absence or weakest response to temperature rise. Among the genes whose expression was significantly altered as a result of de-acclimation, a significant group were genes related to the defence response to stress. In wheat particularly plant hormone related genes, and plant hormones, seem to be playing a crucial role in the response to active de-acclimation, especially ABA and SA. Our results also suggest that in wheat the period of cold-acclimation might be decisive in the later active de-acclimation tolerance.
Project description:Two azide mutagenized lines Freeze Resistance (FR, 75% survival) and Freeze Susceptible (FS, 30% survival) were compared with and without 4°C ± 1.5 cold acclimation of crown tissue to identify genes responsible for the difference in freeze resistance. Keywords: Wheat cold acclimation, stress response, cold, low temperature
Project description:Transcript changes in response to low temperature Total RNA for RNA-seq analysis were extracted from wheat leaf tissues with three biological replicates for each growth condition.
Project description:Two azide mutagenized lines Freeze Resistance (FR, 75% survival) and Freeze Susceptible (FS, 30% survival) were compared with and without 4°C ± 1.5 cold acclimation of crown tissue to identify genes responsible for the difference in freeze resistance. Keywords: Wheat cold acclimation, stress response, cold, low temperature Experiment design (8 hybridizations): Genotype: SD16029 (FR) or SD16169 (FS) Temperature: 25°C or 4°C
Project description:Exposure to cold conditions is a major abiotic stress affecting crop growth and productivity. Elucidation of genetic mechanisms underlying response to low temperature is needed. To assess the relationship between the genes and the cold tolerance of wheat, transcriptomics analyses were performed to study changes in gene profiles of cultivar Jing 411 after cold acclimation and freezing treatment. The wheat cultivar Jing 411 was subjected to transcriptome sequencing. The RNA was sequenced on a HiSeq 2500 platform, and the generated data were analyzed using TopHat v2.0.
Project description:Ectothermic vertebrates are different from mammals that are sensitive to hypothermia and they have to maintain core temperature for survival. Why and how ectothermic animals can survive, grow and reproduce in low temperature have been for a long time a scientifically challenging and important inquiry to biologists. We used a microarray to profile the gill transcriptome in zebrafish (Danio rerio) after exposure to low temperature. Adult zebrafish were acclimated to a low temperature of 12 °C for 1 (1-d) and 30 d (30-d), and the gill transcriptome was compared to wild types by oligonucleotide microarray hybridization. Results showed 11 and 22 transcripts were found to be upregulated by low-temperature treatment for 1-d and 30-d respectively, while 56 and 70 transcrips were downregulated. The gill transcriptome profiles revealed that ionoregulation-related gene was highly upregulated in cold-acclimated zebrafish. This observation encouraged us to investigate the role of ionoregulatory genes in zebrafish gills during cold acclimation. Cold acclimation caused upregulation of genes that are essential for ionocyte specification, differentiation, ionoregulation, and acid/base balance, and also increased the numbers of cells expressing these genes. mRNA expression of epithelial Ca2+ channel (ECaC), one of these genes, was increased in parallel with the level of Ca2+ influx, revealing a functional compensation after long-term acclimation to cold. Phospho-histone H3 and TUNEL staining showed that the cell turnover rate was retarded in cold-acclimated gills. These results suggest that gills may sustain their functions by yielding mature ionocytes from preexisting undifferentiated progenitors in low-temperature environments.