Project description:affy_hexaploid_wheat - hexa - Changes upon polyploidization in hexaploid wheat - transcriptomic changes in synthetic hexaploid derived from a cross between tetraploid and natural diploid. Study aims to understand regulation of gene expression in synthetic and natural wheat allohexaploids (Triticum aestivum), that combines the AB genome of T. turgidum and the D genome of Aegilops tauschii; and which we have recently characterized as genetically stable. We conducted a comprehensive genome-wide analysis of gene expression that allowed us to compare the effect of variability of the D genome progenitor, the trans-generation stability as well as comparison to natural wheat allohexaploid. We used the Affymetrix GeneChip® Wheat Genome Array, on which 55,049 transcripts are represented. Additive expression was shown to represent majority of expression regulation in the synthetic allohexaploids, where expression for more than 93% of transcripts was equal to the one evaluated from equal mixture of parental RNA. This leaves ~2000 (~7%) transcripts, which expression was non-additive. No global gene expression bias or dominance towards any of the progenitor genomes was observed whereas high trans-generational stability and low effect of the D genome progenitor variability were revealed. Our study suggests that gene expression regulation in wheat allohexaploids is early established upon allohexaploidization and highly conserved over generations, as demonstrated by the high similarity of expression with natural wheat allohexaploids. Keywords: genotype and ecotype comparison
Project description:affy_hexaploid_wheat - hexa - Changes upon polyploidization in hexaploid wheat - transcriptomic changes in synthetic hexaploid derived from a cross between tetraploid and natural diploid. Study aims to understand regulation of gene expression in synthetic and natural wheat allohexaploids (Triticum aestivum), that combines the AB genome of T. turgidum and the D genome of Aegilops tauschii; and which we have recently characterized as genetically stable. We conducted a comprehensive genome-wide analysis of gene expression that allowed us to compare the effect of variability of the D genome progenitor, the trans-generation stability as well as comparison to natural wheat allohexaploid. We used the Affymetrix GeneChip® Wheat Genome Array, on which 55,049 transcripts are represented. Additive expression was shown to represent majority of expression regulation in the synthetic allohexaploids, where expression for more than 93% of transcripts was equal to the one evaluated from equal mixture of parental RNA. This leaves ~2000 (~7%) transcripts, which expression was non-additive. No global gene expression bias or dominance towards any of the progenitor genomes was observed whereas high trans-generational stability and low effect of the D genome progenitor variability were revealed. Our study suggests that gene expression regulation in wheat allohexaploids is early established upon allohexaploidization and highly conserved over generations, as demonstrated by the high similarity of expression with natural wheat allohexaploids. Keywords: genotype and ecotype comparison 18 arrays - wheat
Project description:Gene expression levels of newly synthetic triploid wheat (ABD), its chromosome-doubled hexaploid (AABBDD), stable synthetic hexaploid (AABBDD), and their parents, Triticum turgidum (accession KU124, AABB) and Aegilops tauschii (accession KU2074, DD) were compared to understand genome-wide change of gene expressions during the course of amphidiploidization and genome stabilization. Stable synthetic hexaploid which were maintained through self-pollinations for 13 generations using the same combinations of the parents for production of synthetic common wheat.
Project description:We explored the transcriptomic changes of synthetic Brassica allohexaploid by comparing to its parents using a high-throughput RNA-Seq method. A total of 35644409 sequence reads were generated, and 32642 genes were aligned from the data. There were 29260, 29060 and 29697 genes identified in Brassica rapa, Brassica carinata, and Brassica allohexaploid, respectively. We screened differentially expressed genes (DEGs) by a standard of two-fold or greater change in expression and false discovery rate (FDR) no more than 0.001. As a result, 7397 DEGs were detected between Brassica hexaploid and its parents. A large proportion of the 3184 DEGs between Brassica hexaploid and its paternal parent B. rapa was involved in biosynthesis of secondary metabolites, plant-pathogen interaction, photosynthesis, and circadian rhythm. Between Brassica hexaploid and its maternal parent B. carinata, 2233 DEGs were screened. A lot of them had functions of plant-pathogen interaction, plant hormone signal transduction, ribosome, limonene and pinene degradation, photosynthesis, and also biosynthesis of secondary metabolites. In addition, we found many transcription factor genes, methyltransferase and methylation genes that showed differential expression between Brassica hexaploid and its parents. Leaf mRNA profiles of Brassica rapa, Brassica carinata, and Brassica allohexaploid
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:We have employed whole genome microarray expression profiling as a discovery platform to identify genes to alter the transcript accumulation levels in grass-clump dwarf lines, which are synthetic hexaploid lines from triploid hybrids crossed between tetraploid wheat (Triticum turgidum ssp. durum cv. Langdon or T. turgidum ssp. carthlicum) and diploid wheat progenitor Aegilops tauschii (KU2025). No up-regulation of defense-related genes was observed under the normal temperature, and down-regulation of wheat APETALA1-like MADS-box genes, considered to act as flowering promoters, was found in the grass-clump dwarf lines. Together with small RNA sequencing analysis of the grass-clump dwarf line, unusual expression of the miR156/SPLs module could explain the grass-clump dwarf phenotype. Expression patterns were compared between the three synthetic hexaploid lines showing the wild-type phenotype (as a reference) and grass-clump dwarf. Total RNA samples were isolated from crown tissues of the plants grown at 24°C under long day (18-h light and 6-h dark) condition for 8 weeks. Two independent experiments were conducted in each exprement.
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:Many crop species have complex genomes, making the conventional pathway to associating molecular markers with trait variation, which includes genome sequencing, both expensive and time-consuming. We used a streamlined approach to rapidly develop a genomics platform for hexaploid wheat based on the inferred order of expressed sequences. This involved assembly of the transcriptomes for the progenitor genomes of bread wheat, the development of a genetic linkage map comprising 9495 mapped transcriptome-based SNP markers, use of this map to rearrange the genome sequence of Brachypodium distachyon into pseudomolecules representative of the genome organization of wheat and sequence similarity-based mapping onto this resource of the transcriptome assemblies. To demonstrate that this approximation of gene order in wheat is appropriate to underpin association genetics analysis, we undertook Associative Transcriptomics for straw biomass traits, identifying associations and even candidate genes for height, weight and width.