ABSTRACT: 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: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: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:The crown is the critical region for survival of winter wheat exposed to low temperature stresses. When wheat is exposed to non-freezing low temperatures, they can increase their freezing tolerance (cold acclimation, ACC). Changes within the apoplast are thought to be crucial for acquisition of freezing tolerance. However, how individual tissues within the ccrown, namely the shoot apical meristem (SAM, responsible for new shoot growth) and vascular transition zone (VTZ, located at the base of the crown)enhance tolerance to freezing has not yet been characterized. In the present study, we conducted shotgun proteomic analysis of the apoplast fluid to investigate ACC-induced proteins in the SAM and VTZ.
Project description:This dataset is associated with two publications 1. Elucidating the biochemical basis of trans-16:1 fatty acid change in leaves during cold acclimation in wheat. http://doi.org/10.1002/pei3.10044 In this study, comparative RNA-seq analyses with leaf tissues undergoing cold acclimation reveal concerted transcriptome shifts indicating a reduced chloroplast lipid pathway activity and increased cytosolic ER membrane lipid synthesis. To explore the underlying metabolic and transcriptional mechanisms responsible for the reduction of the t16:1 under cold, a detailed lipid analysis and comparative transcriptome study were conducted with four wheat cultivars during cold treatment. The RNA-seq dataset includes four wheat cultivars (Manitou, Winter Manitou, Norstar and Spring Norstar) treated with cold paired with control. The data as a whole show that leaf tissues experience a gradual decrease in chloroplast lipid pathway activity and the variation in the decline of chloroplast lipid synthesis in different cultivars manifest in the rate of decrease in t16:1decrease in leaf tissues. Future efforts are required to determine if and how the down regulation of the chloroplast lipid pathway is related to the development of winter hardiness. 2. Computational genomics insights into cold acclimation in wheat. https://doi.org/10.3389/fgene.2022.1015673 In this study, integrated computational approaches was employed to investigate the transcriptomics and lipidomics data associated with cold acclimation and vernalization in the four wheat genotypes of distinct cold tolerance. Differential expression was investigated between cold treated and control samples and between the winter-habit and spring-habit wheat genotypes. Collectively, 12,676 differentially expressed genes (DEGs) were identified. Principal component analysis of these DEGs indicated that the first, second, and third principal components (PC1, PC2, and PC3) explained the variance in cold treatment, vernalization and cold hardiness, respectively. Differential expression feature extraction (DEFE) analysis revealed that the winter-habit wheat genotype Norstar had high number of unique DEGs (1884 up and 672 down) and 63 winter-habit genes, which were clearly distinctive from the 64 spring-habit genes based on PC1, PC2 and PC3. Correlation analysis revealed 64 cold hardy genes and 39 anti-hardy genes. Cold acclimation encompasses a wide spectrum of biological processes and the involved genes work cohesively as revealed through network propagation and collective association strength of local subnetworks. Integration of transcriptome and lipidomics data revealed that the winter-habit genes, such as COR413-TM1, CIPKs and MYB20, together with the phosphatidylglycerol lipids, PG(34:3) and PG(36:6), played a pivotal role in cold acclimation and coordinated cohesively associated subnetworks to confer cold tolerance. Citations: http://doi.org/10.1002/pei3.10044 https://doi.org/10.3389/fgene.2022.1015673
Project description:Chromosome 5A of wheat is a major regulator of freezing tolerance. It harbours gene loci controlling freezing tolerance (Fr-A1 and Fr-A2) and vernalization requirement (Vrn-A1). The number of cold-responsive genes and their functional classification was studied by cDNA macroarray-based transcript profiling in the moderately freezing-sensitive wheat (Triticum aestivum L.) variety Chinese Spring and two derived chromosome 5A substitution lines exhibiting lower or higher levels of freezing tolerance, respectively. During 21-days of cold acclimation at 2 °C the transcript level changed significantly for 681 (6.6%) out of 10,297 studied unigenes. The freezing-tolerant substitution line exhibited about 1.5-fold higher number of differentially expressed genes compared to the sensitive one. Transcript levels of several genes were altered by cold treatment only in one of the three genotypes. For 78 genes regulation by factors hosted on chromosome 5A was determined and postulated. These genes encoded proteins involved in transcriptional regulation, defence processes and carbohydrate metabolism. Three of the chromosome 5A-affected genes, having especially strong and rapid cold-induced changes of transcript level, namely Tacr7 (Triticum aesticum cold-responsive gene 7 homolog), Cab (Ca2+-binding), and Dem (deficient embryo and meristems) were genetically mapped and characterized in further detail. Only the gene Cab was located on chromosome 5A, whereas Tacr7 and Dem resided on other chromosomes. Although chromosome 5A-affected genes are also found to be localised on the same chromosome, the present findings indicate that chromosome 5A is strongly involved in trans-regulation of genes potentially due to the presence of regulatory loci, like Fr-A2, which is harboring numerous CBF transcription factors.
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:Different wheat cultivars may be classified as either winter or spring varieties depending on whether they require exposure to an extended period of cold in order to become competent to flower. Using a growth regime that mimics the conditions that occur during a typical winter in Britain, we wished to survey the genes that are involved in phase transition as well as those involved in cold-acclimation. Keywords: Time course