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Juan B. Alvarez - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterization of novel LMW-i glutenin subunit genes from Triticum Urartu Thum. ex Gandil.
Theoretical and Applied Genetics, 2015Co-Authors: Susana Cuesta, Carlos Guzman, Juan B. AlvarezAbstract:Key message A high level of genetic diversity was found in LMW-i genes from Triticum Urartu, resulting in detection of 11 novel alleles. The variability detected could affect gluten quality . Abstract Low-molecular weight glutenin subunits are important in determining the viscoelastic properties of wheat dough. Triticum Urartu Thum. ex Gandil., which is related to the A genome of polyploid wheat, has been shown as a good source of variation for these subunits. The present study evaluated the variability of LMW-i genes in this species. High polymorphism was found in the sequences analysed and resulted in the detection of 11 novel alleles, classified into two sets (Group-I and -II) showing unique SNPs and InDels. Both groups were associated with Glu - A3 - 1 genes from common wheat. In general, deduced proteins from Group-II genes possessed a higher proportion of glutamine and proline, which has been previously suggested to be related with good quality. Moreover, there were other changes compared to common wheat. This novel variation could affect dough quality. Additional epitopes for celiac disease were also detected, suggesting that these subunits could be highly reactive. The results showed that T. Urartu could be an important source of genetic variability for LMW-i genes that could enlarge the genetic pool of modern wheat.
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Molecular characterization of novel LMW-i glutenin subunit genes from Triticum Urartu Thum. ex Gandil.
TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik, 2015Co-Authors: Susana Cuesta, Carlos Guzman, Juan B. AlvarezAbstract:Key message A high level of genetic diversity was found in LMW-i genes from Triticum Urartu, resulting in detection of 11 novel alleles. The variability detected could affect gluten quality.
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Molecular characterization of a novel waxy allele (Wx-A ^ u 1a) from Triticum Urartu Thum. ex Gandil.
Genetic Resources and Crop Evolution, 2012Co-Authors: Carlos Guzman, Juan B. AlvarezAbstract:Granule Bound Starch Synthase I, or waxy protein, is the sole enzyme responsible for the accumulation of amylose during the development of starch granules in wheat. The full coding region of the waxy ( Wx ) gene was sequenced in Triticum Urartu , (a wild diploid species) and is related to the A genome of polyploid wheats. The Wx gene of T. Urartu (Wx - A ^ u 1 ) showed a homology of ~88.0 % with Wx - A1 from polyploid wheats. A greater homology was found with Wx - A ^ m 1 from the diploid cultivated wheat einkorn. Most of the differences were found in introns although several changes were also detected in exons that led to amino acid changes in the transit peptide and mature protein. These results show the potential of T. Urartu as a source of new alleles that could be used in the breeding of durum and common wheat in order to synthesize starches with different properties.
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Molecular characterization of a novel waxy allele ( Wx - A u 1a ) from Triticum Urartu Thum. ex Gandil.
Genetic Resources and Crop Evolution, 2012Co-Authors: Carlos Guzman, Juan B. AlvarezAbstract:Granule Bound Starch Synthase I, or waxy protein, is the sole enzyme responsible for the accumulation of amylose during the development of starch granules in wheat. The full coding region of the waxy (Wx) gene was sequenced in Triticum Urartu, (a wild diploid species) and is related to the A genome of polyploid wheats. The Wx gene of T. Urartu (Wx-Au1) showed a homology of ~88.0 % with Wx-A1 from polyploid wheats. A greater homology was found with Wx-Am1 from the diploid cultivated wheat einkorn. Most of the differences were found in introns although several changes were also detected in exons that led to amino acid changes in the transit peptide and mature protein. These results show the potential of T. Urartu as a source of new alleles that could be used in the breeding of durum and common wheat in order to synthesize starches with different properties.
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Molecular characterization of the Glu-Ay gene from Triticum Urartu for its potential use in quality wheat breeding
Plant Genetic Resources, 2011Co-Authors: M. V. Gutierrez, L M Martin, Carlos Guzman, Juan B. AlvarezAbstract:Triticum Urartu Thum. ex Gandil. is a wild species identified as A-genome donor for polyploid wheats, which could be used as gene source for wheat breeding. The high-molecular weight glutenin subunits are endosperm storage proteins that are associated with bread-making quality. In T. Urartu , these proteins are encoded by the Ax and Ay genes at the Glu-A u 1 locus. The Ay gene of 17 Glu-A u 1 allelic variants previously detected in this species has been analysed using PCR amplification and digestion of the PCR products with two endonucleases ( Dde I and Pst I). The combination of two restriction patterns has revealed variations between the active and inactive alleles, and within each type. This variation, especially that detected among the active alleles, could enlarge the high-quality genetic pool of modern wheat and be used for bread-making quality improvement in durum and common wheat.
Carlos Guzman - One of the best experts on this subject based on the ideXlab platform.
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Molecular characterization of novel LMW-i glutenin subunit genes from Triticum Urartu Thum. ex Gandil.
Theoretical and Applied Genetics, 2015Co-Authors: Susana Cuesta, Carlos Guzman, Juan B. AlvarezAbstract:Key message A high level of genetic diversity was found in LMW-i genes from Triticum Urartu, resulting in detection of 11 novel alleles. The variability detected could affect gluten quality . Abstract Low-molecular weight glutenin subunits are important in determining the viscoelastic properties of wheat dough. Triticum Urartu Thum. ex Gandil., which is related to the A genome of polyploid wheat, has been shown as a good source of variation for these subunits. The present study evaluated the variability of LMW-i genes in this species. High polymorphism was found in the sequences analysed and resulted in the detection of 11 novel alleles, classified into two sets (Group-I and -II) showing unique SNPs and InDels. Both groups were associated with Glu - A3 - 1 genes from common wheat. In general, deduced proteins from Group-II genes possessed a higher proportion of glutamine and proline, which has been previously suggested to be related with good quality. Moreover, there were other changes compared to common wheat. This novel variation could affect dough quality. Additional epitopes for celiac disease were also detected, suggesting that these subunits could be highly reactive. The results showed that T. Urartu could be an important source of genetic variability for LMW-i genes that could enlarge the genetic pool of modern wheat.
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Molecular characterization of novel LMW-i glutenin subunit genes from Triticum Urartu Thum. ex Gandil.
TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik, 2015Co-Authors: Susana Cuesta, Carlos Guzman, Juan B. AlvarezAbstract:Key message A high level of genetic diversity was found in LMW-i genes from Triticum Urartu, resulting in detection of 11 novel alleles. The variability detected could affect gluten quality.
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Molecular characterisation of the amino- and carboxyl-domains in different Glu-A1x alleles of Triticum Urartu Thum. ex Gandil
Theoretical and Applied Genetics, 2013Co-Authors: J. B. Alvarez, M. Victoria Gutiérrez, Carlos Guzman, L M MartinAbstract:The wild diploid wheat (Triticum Urartu Thum. ex Gandil.) is a potential gene source for wheat breeding, as this species has been identified as the A-genome donor in polyploid wheats. One important wheat breeding trait is bread-making quality, which is associated in bread wheat (T. aestivum ssp. aestivum L. em. Thell.) with the high-molecular-weight glutenin subunits. In T. Urartu, these proteins are encoded by the Glu-A1x and Glu-A1Ay genes at the Glu-A (u) 1 locus. The Glu-A1x genes of 12 Glu-A (u) 1 allelic variants previously detected in this species were analysed using PCR amplification and sequencing. Data showed wide diversity for the Glu-A1x alleles in T. Urartu, which also showed clear differences to the bread wheat alleles. This variation could enlarge the high-quality genetic pool of modern wheat and be used to diversify the bread-making quality in durum (T. turgidum ssp. durum Desf. em. Husn.) and common wheat.
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Molecular characterization of a novel waxy allele (Wx-A ^ u 1a) from Triticum Urartu Thum. ex Gandil.
Genetic Resources and Crop Evolution, 2012Co-Authors: Carlos Guzman, Juan B. AlvarezAbstract:Granule Bound Starch Synthase I, or waxy protein, is the sole enzyme responsible for the accumulation of amylose during the development of starch granules in wheat. The full coding region of the waxy ( Wx ) gene was sequenced in Triticum Urartu , (a wild diploid species) and is related to the A genome of polyploid wheats. The Wx gene of T. Urartu (Wx - A ^ u 1 ) showed a homology of ~88.0 % with Wx - A1 from polyploid wheats. A greater homology was found with Wx - A ^ m 1 from the diploid cultivated wheat einkorn. Most of the differences were found in introns although several changes were also detected in exons that led to amino acid changes in the transit peptide and mature protein. These results show the potential of T. Urartu as a source of new alleles that could be used in the breeding of durum and common wheat in order to synthesize starches with different properties.
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Molecular characterization of a novel waxy allele ( Wx - A u 1a ) from Triticum Urartu Thum. ex Gandil.
Genetic Resources and Crop Evolution, 2012Co-Authors: Carlos Guzman, Juan B. AlvarezAbstract:Granule Bound Starch Synthase I, or waxy protein, is the sole enzyme responsible for the accumulation of amylose during the development of starch granules in wheat. The full coding region of the waxy (Wx) gene was sequenced in Triticum Urartu, (a wild diploid species) and is related to the A genome of polyploid wheats. The Wx gene of T. Urartu (Wx-Au1) showed a homology of ~88.0 % with Wx-A1 from polyploid wheats. A greater homology was found with Wx-Am1 from the diploid cultivated wheat einkorn. Most of the differences were found in introns although several changes were also detected in exons that led to amino acid changes in the transit peptide and mature protein. These results show the potential of T. Urartu as a source of new alleles that could be used in the breeding of durum and common wheat in order to synthesize starches with different properties.
Daowen Wang - One of the best experts on this subject based on the ideXlab platform.
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Reactions of Triticum Urartu accessions to two races of the wheat yellow rust pathogen
KeAi, 2018Co-Authors: Jibin Xiao, Lingli Dong, Huaibing Jin, Juncheng Zhang, Kunpu Zhang, Na Liu, Xinyun Han, Hongyuan Zheng, Wenming Zheng, Daowen WangAbstract:Triticum Urartu (AA, 2n = 2x = 14), a wild grass endemic to the Fertile Crescent (FC), is the progenitor of the A subgenome in common wheat. It belongs to the primary gene pool for wheat improvement. Here, we evaluated the yellow rust (caused by Puccinia striiformis f. sp. tritici, Pst) reactions of 147 T. Urartu accessions collected from different parts of the FC. The reactions varied from susceptibility to strong resistance. In general, there were more accessions with stronger resistance to race CYR33 than to CYR 32. In most cases the main form of defense was a moderate resistance characterized by the presence of necrotic/chlorotic lesions with fewer Pst uredinia on the leaves. Forty two accessions displayed resistance to both races. Histological analysis showed that Pst growth was abundant in the compatible interaction but significantly suppressed by the resistant response. Gene silencing mediated by Barley stripe mosaic virus was effective in two T. Urartu accessions with different resistance responses, indicating that this method can expedite future functional analysis of resistance genes. Our data suggest that T. Urartu is a valuable source of resistance to yellow rust, and represents a model for studying the genetic, genomic and molecular basis underlying interaction between wheat and Pst. Keywords: Common wheat, Disease resistance, Gene silencing, Puccinia striiformi
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Reactions of Triticum Urartu accessions to two races of the wheat yellow rust pathogen
The Crop Journal, 2018Co-Authors: Jibin Xiao, Lingli Dong, Huaibing Jin, Juncheng Zhang, Kunpu Zhang, Na Liu, Xinyun Han, Hongyuan Zheng, Wenming Zheng, Daowen WangAbstract:Abstract Triticum Urartu (AA, 2n = 2x = 14), a wild grass endemic to the Fertile Crescent (FC), is the progenitor of the A subgenome in common wheat. It belongs to the primary gene pool for wheat improvement. Here, we evaluated the yellow rust (caused by Puccinia striiformis f. sp. tritici, Pst) reactions of 147 T. Urartu accessions collected from different parts of the FC. The reactions varied from susceptibility to strong resistance. In general, there were more accessions with stronger resistance to race CYR33 than to CYR 32. In most cases the main form of defense was a moderate resistance characterized by the presence of necrotic/chlorotic lesions with fewer Pst uredinia on the leaves. Forty two accessions displayed resistance to both races. Histological analysis showed that Pst growth was abundant in the compatible interaction but significantly suppressed by the resistant response. Gene silencing mediated by Barley stripe mosaic virus was effective in two T. Urartu accessions with different resistance responses, indicating that this method can expedite future functional analysis of resistance genes. Our data suggest that T. Urartu is a valuable source of resistance to yellow rust, and represents a model for studying the genetic, genomic and molecular basis underlying interaction between wheat and Pst.
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An analysis of homoeologous microsatellites from Triticum Urartu and Triticum monococcum
Plant Science, 2004Co-Authors: Jianrong Bai, Xu Jia, Kunfan Liu, Daowen WangAbstract:Compared to hexaploid common wheat (Triticum aestivum, 2n=6x=42, AABBDD), little is known about microsatellites and their nucleotide sequences in related diploid wheat species carrying the Au or Am genomes. We tried to amplify homoeologous microsatellites from Triticum Urartu (2n=2x=14, AuAu) and Triticum monococcum (2n=2x=14, AmAm ) using 54 sets of PCR primers originally designed for the microsatellites of the A genome of common wheat, and found that 26 primer sets amplified microsatellite products in all seven accessions of T. Urartu and all three accessions of T. monococcum. On the basis of the amplification results, the nucleotide sequences of three representative homoeologous microsatellites were amplified from multiple accessions of T. Urartu and T. monococcum and compared. The results showed that homoeologous microsatellites from T. Urartu and T. monococcum varied in their nucleotide sequences. The patterns of nucleotide sequence variations differed among individual loci, with some showing variations only in the repeat regions or the flanking sequences and others in both the repeat regions and the flanking sequences. Nucleotide sequence variations in the flanking regions were caused by base substitution and/or indel mutations. The variations in the repeat regions involved changes in the repeat number or a combination of repeat number changes and insertions of additional types of dinucleotide sequences.
Dongcheng Liu - One of the best experts on this subject based on the ideXlab platform.
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TubZIP28 , a novel bZIP family transcription factor from Triticum Urartu , and TabZIP28 , its homologue from Triticum aestivum , enhance starch synthesis in wheat
The New phytologist, 2020Co-Authors: Yanhong Song, Wenlong Yang, Jiazhu Sun, Kehui Zhan, Luo Guangbin, Lisha Shen, Dangqun Cui, Dongcheng LiuAbstract:Starch in wheat grain provides humans with carbohydrates and influences the quality of wheaten food. However, no transcriptional regulator of starch synthesis has been identified first in common wheat (Triticum aestivum) due to the complex genome. Here, a novel basic leucine zipper (bZIP) family transcription factor TubZIP28 was found to be preferentially expressed in the endosperm throughout grain-filling stages in Triticum Urartu, the A genome donor of common wheat. When TubZIP28 was overexpressed in common wheat, the total starch content increased by c. 4%, which contributed to c. 5% increase in the thousand kernel weight. The grain weight per plant of overexpression wheat was also elevated by c. 9%. Both in vitro and in vivo assays showed that TubZIP28 bound to the promoter of cytosolic AGPase and enhanced both the transcription and activity of the latter. Knockout of the homologue TabZIP28 in common wheat resulted in declines of both the transcription and activity of cytosolic AGPase in developing endosperms and c. 4% reduction of the total starch in mature grains. To the best of our knowledge, TubZIP28 and TabZIP28 are transcriptional activators of starch synthesis first identified in wheat, and they could be superior targets to improve the starch content and yield potential of wheat.
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Genetic diversity, population structure and marker-trait associations for agronomic and grain traits in wild diploid wheat Triticum Urartu
BMC plant biology, 2017Co-Authors: X.-r. Wang, Wenlong Yang, Dongcheng Liu, Jiazhu Sun, Guangbin Luo, Kehui Zhan, Aimin ZhangAbstract:Abstract Background Wild diploid wheat, Triticum Urartu ( T. Urartu ) is the progenitor of bread wheat, and understanding its genetic diversity and genome function will provide considerable reference for dissecting genomic information of common wheat. Results In this study, we investigated the morphological and genetic diversity and population structure of 238 T. Urartu accessions collected from different geographic regions. This collection had 19.37 alleles per SSR locus and its polymorphic information content (PIC) value was 0.76, and the PIC and Nei’s gene diversity (GD) of high-molecular-weight glutenin subunits (HMW-GSs) were 0.86 and 0.88, respectively. UPGMA clustering analysis indicated that the 238 T. Urartu accessions could be classified into two subpopulations, of which Cluster I contained accessions from Eastern Mediterranean coast and those from Mesopotamia and Transcaucasia belonged to Cluster II. The wide range of genetic diversity along with the manageable number of accessions makes it one of the best collections for mining valuable genes based on marker-trait association. Significant associations were observed between simple sequence repeats (SSR) or HMW-GSs and six morphological traits: heading date (HD), plant height (PH), spike length (SPL), spikelet number per spike (SPLN), tiller angle (TA) and grain length (GL). Conclusions Our data demonstrated that SSRs and HMW-GSs were useful markers for identification of beneficial genes controlling important traits in T. Urartu , and subsequently for their conservation and future utilization, which may be useful for genetic improvement of the cultivated hexaploid wheat.
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Genome-, Transcriptome- and Proteome-Wide Analyses of the Gliadin Gene Families in Triticum Urartu.
PloS one, 2015Co-Authors: Yanlin Zhang, Wenlong Yang, Dongcheng Liu, Jiazhu Sun, Aimin Zhang, Guangbin Luo, Dongzhi Wang, Kehui ZhanAbstract:Gliadins are the major components of storage proteins in wheat grains, and they play an essential role in the dough extensibility and nutritional quality of flour. Because of the large number of the gliadin family members, the high level of sequence identity, and the lack of abundant genomic data for Triticum species, identifying the full complement of gliadin family genes in hexaploid wheat remains challenging. Triticum Urartu is a wild diploid wheat species and considered the A-genome donor of polyploid wheat species. The accession PI428198 (G1812) was chosen to determine the complete composition of the gliadin gene families in the wheat A-genome using the available draft genome. Using a PCR-based cloning strategy for genomic DNA and mRNA as well as a bioinformatics analysis of genomic sequence data, 28 gliadin genes were characterized. Of these genes, 23 were α-gliadin genes, three were γ-gliadin genes and two were ω-gliadin genes. An RNA sequencing (RNA-Seq) survey of the dynamic expression patterns of gliadin genes revealed that their synthesis in immature grains began prior to 10 days post-anthesis (DPA), peaked at 15 DPA and gradually decreased at 20 DPA. The accumulation of proteins encoded by 16 of the expressed gliadin genes was further verified and quantified using proteomic methods. The phylogenetic analysis demonstrated that the homologs of these α-gliadin genes were present in tetraploid and hexaploid wheat, which was consistent with T. Urartu being the A-genome progenitor species. This study presents a systematic investigation of the gliadin gene families in T. Urartu that spans the genome, transcriptome and proteome, and it provides new information to better understand the molecular structure, expression profiles and evolution of the gliadin genes in T. Urartu and common wheat.
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Composition, variation, expression and evolution of low-molecular-weight glutenin subunit genes in Triticum Urartu
BMC plant biology, 2015Co-Authors: Guangbin Luo, Wenlong Yang, Jiazhu Sun, Aimin Zhang, Yanlin Zhang, Kehui Zhan, Xiaofei Zhang, Dongcheng LiuAbstract:Wheat (AABBDD, 2n = 6x = 42) is a major dietary component for many populations across the world. Bread-making quality of wheat is mainly determined by glutenin subunits, but it remains challenging to elucidate the composition and variation of low-molecular-weight glutenin subunits (LMW-GS) genes, the major components for glutenin subunits in hexaploid wheat. This problem, however, can be greatly simplified by characterizing the LMW-GS genes in Triticum Urartu, the A-genome donor of hexaploid wheat. In the present study, we exploited the high-throughput molecular marker system, gene cloning, proteomic methods and molecular evolutionary genetic analysis to reveal the composition, variation, expression and evolution of LMW-GS genes in a T. Urartu population from the Fertile Crescent region. Eight LMW-GS genes, including four m-type, one s-type and three i-type, were characterized in the T. Urartu population. Six or seven genes, the highest number at the Glu-A3 locus, were detected in each accession. Three i-type genes, each containing more than six allelic variants, were tightly linked because of their co-segregation in every accession. Only 2-3 allelic variants were detected for each m- and s-type gene. The m-type gene, TuA3-385, for which homologs were previously characterized only at Glu-D3 locus in common wheat and Aegilops tauschii, was detected at Glu-A3 locus in T. Urartu. TuA3-460 was the first s-type gene identified at Glu-A3 locus. Proteomic analysis showed 1-4 genes, mainly i-type, expressed in individual accessions. About 62% accessions had three active i-type genes, rather than one or two in common wheat. Southeastern Turkey might be the center of origin and diversity for T. Urartu due to its abundance of LMW-GS genes/genotypes. Phylogenetic reconstruction demonstrated that the characterized T. Urartu might be the direct donor of the Glu-A3 locus in common wheat varieties. Compared with the Glu-A3 locus in common wheat, a large number of highly diverse LMW-GS genes and active genes were characterized in T. Urartu, demonstrating that this progenitor might provide valuable genetic resources for LMW-GS genes to improve the quality of common wheat. The phylogenetic analysis provided molecular evidence and confirmed that T. Urartu was the A-genome donor of hexaploid wheat.
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Genome-wide analysis of the heat shock transcription factor family in Triticum Urartu and Aegilops tauschii
Plant Omics, 2014Co-Authors: Wenlong Yang, Dongcheng Liu, Jiazhu Sun, Aimin ZhangAbstract:Heat shock proteins (Hsps) are believed to play essential roles in developmental processes and in responses to heat stress. Heat shock transcription factors (Hsfs) are important Hsp regulators, but their functions are poorly understood, especially in wheat. In this study, a comprehensive bioinformatics analysis was conducted in wheat A and D genome donors, 'Triticum Urartu' and 'Aegilops tauschii', the genomic sequences of which were published recently. The results showed that 13 Hsf proteins were identified in both T. Urartu and Ae. tauschii, and they could be classified into three groups according to structure; seven Hsfs belonged to group A, two to group B, and three to group C. Expression analyses of these Hsf genes in different tissues of T. Urartu and in the response to heat stress were conducted using quantitative RT-PCR. Several Hsf genes in group A ('Tuhsf03, Tuhsf05, Tuhsf06, Tuhsf10') had 19-292-fold increases in transcript levels versus the control in different tissues of 'T. Urartu' and could be induced by heat stress, while the transcripts of group B and group C Hsf genes could hardly be detected. These results provide important information for cloning, expression, and functional studies of Hsfs in wheat.
Lingli Dong - One of the best experts on this subject based on the ideXlab platform.
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Genome sequence of the progenitor of wheat A subgenome Triticum Urartu
Nature, 2018Co-Authors: Hong-qing Ling, Xiaoli Shi, Hui Liu, Lingli Dong, Hua Sun, Yinghao Cao, Qiang Gao, Shusong ZhengAbstract:Triticum Urartu (diploid, AA) is the progenitor of the A subgenome of tetraploid (Triticum turgidum, AABB) and hexaploid (Triticum aestivum, AABBDD) wheat1,2. Genomic studies of T. Urartu have been useful for investigating the structure, function and evolution of polyploid wheat genomes. Here we report the generation of a high-quality genome sequence of T. Urartu by combining bacterial artificial chromosome (BAC)-by-BAC sequencing, single molecule real-time whole-genome shotgun sequencing3, linked reads and optical mapping4,5. We assembled seven chromosome-scale pseudomolecules and identified protein-coding genes, and we suggest a model for the evolution of T. Urartu chromosomes. Comparative analyses with genomes of other grasses showed gene loss and amplification in the numbers of transposable elements in the T. Urartu genome. Population genomics analysis of 147 T. Urartu accessions from across the Fertile Crescent showed clustering of three groups, with differences in altitude and biostress, such as powdery mildew disease. The T. Urartu genome assembly provides a valuable resource for studying genetic variation in wheat and related grasses, and promises to facilitate the discovery of genes that could be useful for wheat improvement. The genome sequence of Triticum Urartu, the progenitor of the A subgenome of hexaploid wheat, provides insight into genome duplication during grass evolution.
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Reactions of Triticum Urartu accessions to two races of the wheat yellow rust pathogen
The Crop Journal, 2018Co-Authors: Jibin Xiao, Lingli Dong, Huaibing Jin, Juncheng Zhang, Kunpu Zhang, Na Liu, Xinyun Han, Hongyuan Zheng, Wenming Zheng, Daowen WangAbstract:Abstract Triticum Urartu (AA, 2n = 2x = 14), a wild grass endemic to the Fertile Crescent (FC), is the progenitor of the A subgenome in common wheat. It belongs to the primary gene pool for wheat improvement. Here, we evaluated the yellow rust (caused by Puccinia striiformis f. sp. tritici, Pst) reactions of 147 T. Urartu accessions collected from different parts of the FC. The reactions varied from susceptibility to strong resistance. In general, there were more accessions with stronger resistance to race CYR33 than to CYR 32. In most cases the main form of defense was a moderate resistance characterized by the presence of necrotic/chlorotic lesions with fewer Pst uredinia on the leaves. Forty two accessions displayed resistance to both races. Histological analysis showed that Pst growth was abundant in the compatible interaction but significantly suppressed by the resistant response. Gene silencing mediated by Barley stripe mosaic virus was effective in two T. Urartu accessions with different resistance responses, indicating that this method can expedite future functional analysis of resistance genes. Our data suggest that T. Urartu is a valuable source of resistance to yellow rust, and represents a model for studying the genetic, genomic and molecular basis underlying interaction between wheat and Pst.
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Reactions of Triticum Urartu accessions to two races of the wheat yellow rust pathogen
KeAi, 2018Co-Authors: Jibin Xiao, Lingli Dong, Huaibing Jin, Juncheng Zhang, Kunpu Zhang, Na Liu, Xinyun Han, Hongyuan Zheng, Wenming Zheng, Daowen WangAbstract:Triticum Urartu (AA, 2n = 2x = 14), a wild grass endemic to the Fertile Crescent (FC), is the progenitor of the A subgenome in common wheat. It belongs to the primary gene pool for wheat improvement. Here, we evaluated the yellow rust (caused by Puccinia striiformis f. sp. tritici, Pst) reactions of 147 T. Urartu accessions collected from different parts of the FC. The reactions varied from susceptibility to strong resistance. In general, there were more accessions with stronger resistance to race CYR33 than to CYR 32. In most cases the main form of defense was a moderate resistance characterized by the presence of necrotic/chlorotic lesions with fewer Pst uredinia on the leaves. Forty two accessions displayed resistance to both races. Histological analysis showed that Pst growth was abundant in the compatible interaction but significantly suppressed by the resistant response. Gene silencing mediated by Barley stripe mosaic virus was effective in two T. Urartu accessions with different resistance responses, indicating that this method can expedite future functional analysis of resistance genes. Our data suggest that T. Urartu is a valuable source of resistance to yellow rust, and represents a model for studying the genetic, genomic and molecular basis underlying interaction between wheat and Pst. Keywords: Common wheat, Disease resistance, Gene silencing, Puccinia striiformi
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Draft genome of the wheat A-genome progenitor Triticum Urartu
Nature, 2013Co-Authors: Hong-qing Ling, Lingli Dong, Hua Sun, Dongcheng Liu, Shancen Zhao, Junyi Wang, Chi Zhang, Huajie Fan, Yong TaoAbstract:The genome sequence and its analysis of the diploid wild wheat Triticum Urartu (progenitor of the wheat A genome) represent a tool for studying the complex, polyploid wheat genomes and should be a valuable resource for the genetic improvement of wheat. The hexaploid genome of bread wheat Triticum aestivum, designated AABBDD, evolved as a result of hybridization between three ancestral grasses. Two papers published in the issue of Nature present genome sequences and analysis of two of these wheat progenitors. First, the genome sequence of the diploid wild wheat T. Urartu (ancestor of the A genome), which resembles cultivated wheat more strongly than either Aegilops speltoides (the B ancestor) or Ae. tauschii (the D donor). And second, the Ae. tauschii genome, together with an analysis of its transcriptome. These genomes and their analyses will be powerful tools for the study of complex, polyploid wheat genomes and a valuable resource for genetic improvement of wheat. Bread wheat (Triticum aestivum, AABBDD) is one of the most widely cultivated and consumed food crops in the world. However, the complex polyploid nature of its genome makes genetic and functional analyses extremely challenging. The A genome, as a basic genome of bread wheat and other polyploid wheats, for example, T. turgidum (AABB), T. timopheevii (AAGG) and T. zhukovskyi (AAGGAmAm), is central to wheat evolution, domestication and genetic improvement1. The progenitor species of the A genome is the diploid wild einkorn wheat T. Urartu2, which resembles cultivated wheat more extensively than do Aegilops speltoides (the ancestor of the B genome3) and Ae. tauschii (the donor of the D genome4), especially in the morphology and development of spike and seed. Here we present the generation, assembly and analysis of a whole-genome shotgun draft sequence of the T. Urartu genome. We identified protein-coding gene models, performed genome structure analyses and assessed its utility for analysing agronomically important genes and for developing molecular markers. Our T. Urartu genome assembly provides a diploid reference for analysis of polyploid wheat genomes and is a valuable resource for the genetic improvement of wheat.
