Publications by authors named "Jiazhu Sun"

27 Publications

  • Page 1 of 1

The MYB family transcription factor TuODORANT1 from Triticum urartu and the homolog TaODORANT1 from Triticum aestivum inhibit seed storage protein synthesis in wheat.

Plant Biotechnol J 2021 May 5. Epub 2021 May 5.

State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology/Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China.

Seed storage proteins (SSPs) are determinants of wheat end-product quality. SSP synthesis is mainly regulated at the transcriptional level. Few transcriptional regulators of SSP synthesis have been identified in wheat and this study aims to identify novel SSP gene regulators. Here, the R2R3 MYB transcription factor TuODORANT1 from Triticum urartu was found to be preferentially expressed in the developing endosperm during grain filling. In common wheat (Triticum aestivum) overexpressing TuODORANT1, the transcription levels of all the SSP genes tested by RNA-Seq analysis were reduced by 49.71% throughout grain filling, which contributed to 13.38%-35.60% declines in the total SSP levels of mature grains. In in vitro assays, TuODORANT1 inhibited both the promoter activities and the transcription of SSP genes by 1- to 13-fold. The electrophoretic mobility shift assay (EMSA) and ChIP-qPCR analysis demonstrated that TuODORANT1 bound to the cis-elements 5'-T/CAACCA-3' and 5'-T/CAACT/AG-3' in SSP gene promoters both in vitro and in vivo. Similarly, the homolog TaODORANT1 in common wheat hindered both the promoter activities and the transcription of SSP genes by 1- to 112-fold in vitro. Knockdown of TaODORANT1 in common wheat led to 14.73%-232.78% increases in the transcription of the tested SSP genes, which contributed to 11.43%-19.35% elevation in the total SSP levels. Our data show that both TuODORANT1 and TaODORANT1 are repressors of SSP synthesis.
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http://dx.doi.org/10.1111/pbi.13604DOI Listing
May 2021

Effects of fluorescent light cystoscopy in non-muscle-invasive bladder cancer: A systematic review and meta-analysis.

Photodiagnosis Photodyn Ther 2021 Mar 9;34:102248. Epub 2021 Mar 9.

Department of Urology, First Affiliated Hospital, School of Medicine, Zhejiang University, Qingchun Road 79, Hangzhou, 310003, Zhejiang, China. Electronic address:

Background: The benefits of fluorescent light (FL) cystoscopy with 5-aminolevulinic acid (5-ALA) or hexaminolevulinate (HAL) in non-muscle-invasive bladder cancer (NMIBC) have been mentioned in many trials. Meanwhile, several problems need to be addressed such as the rate of residual disease following these procedures.

Objective: To assess the effects of FL cystoscopy compared with white light (WL) cystoscopy on the rate of residual Ta, T1, and carcinoma in situ (CIS) tumors, recurrence-free survival (RFS) and progression-free survival (PFS).

Methods: A search in the databases PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM) was undertaken. Studies were included if their outcomes included the residual tumor rate, PFS or RFS. The data was analyzed by REVMAN 5.3 and STATA 14.0.

Results: The residual tumor rate of the FL group was lower than that of the WL group (relative risk [RR] 0.42; 95 % confidence interval [CI] 0.26-0.80; P = 0.007), which was consistent with the residual Ta rate (RR 0.44; 95 % CI 0.28-0.69; P = 0.0004), the residual T1 rate (RR 0.42; 95 % CI 0.21-0.83; P = 0.01) and the residual CIS rate (RR 0.39; 95 % CI 0.19-0.80; P = 0.01). RFS at the 12-month follow-up (RR 1.15; 95 % CI 1.08-1.28; P = 0.0002) and 24-month follow-up (RR 1.26; 95 % CI 1.17-1.35; P < 0.00001) in the FL group was significantly higher than that in the WL group. However, no statistically significant differences were found in PFS at the 12-month follow-up (RR 1.01; 95 % CI 0.99-1.03; P = 0.17) or 24-month follow-up (RR 1.00; 95 % CI 0.97-1.03; P = 0.95).

Conclusion: FL cystoscopy was related to a reduced residual tumor rate compared with WL cystoscopy in NMIBC, which was also consistent with the Ta, T1 and residual CIS rates. RFS was higher in patients with FL cystoscopy at the 12- to 24-month follow-up.
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http://dx.doi.org/10.1016/j.pdpdt.2021.102248DOI Listing
March 2021

A novel NAC family transcription factor SPR suppresses seed storage protein synthesis in wheat.

Plant Biotechnol J 2021 May 4;19(5):992-1007. Epub 2021 Jan 4.

State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China.

The synthesis of seed storage protein (SSP) is mainly regulated at the transcriptional level. However, few transcriptional regulators of SSP synthesis have been characterized in common wheat (Triticum aestivum) owing to the complex genome. As the A genome donor of common wheat, Triticum urartu could be an elite model in wheat research considering its simple genome. Here, a novel NAC family transcription factor TuSPR from T. urartu was found preferentially expressed in developing endosperm during grain-filling stages. In common wheat transgenically overexpressing TuSPR, the content of total SSPs was reduced by c. 15.97% attributed to the transcription declines of SSP genes. Both in vitro and in vivo assays showed that TuSPR bound to the cis-element 5'-CANNTG-3' distributed in SSP gene promoters and suppressed the transcription. The homolog in common wheat TaSPR shared a conserved function with TuSPR on SSP synthesis suppression. The knock-down of TaSPR in common wheat resulted in 7.07%-20.34% increases in the total SSPs. Both TuSPR and TaSPR could be superior targets in genetic engineering to manipulate SSP content in wheat, and this work undoubtedly expands our knowledge of SSP gene regulation.
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http://dx.doi.org/10.1111/pbi.13524DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8131056PMC
May 2021

TaCKX gene family, at large, is associated with thousand-grain weight and plant height in common wheat.

Theor Appl Genet 2020 Nov 27;133(11):3151-3163. Epub 2020 Aug 27.

State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.

Key Message: We used SMRT sequencing and explored the haplotypes of TaCKX genes, linked with thousand-grain weight and plant height, and developed the functionally validated markers, which can be used in the marker-assisted breeding program. Cytokinin oxidase/dehydrogenase (CKX) enzymes catalyze the permanent degradation of cytokinins. Identification of the TaCKX alleles associated with yield traits and the development of functional markers is the first step in using these alleles in marker-assisted breeding program. To identify the alleles, we sequenced the genome fragments, containing TaCKX genes from 48 wheat genotypes, by PacBio sequencing. Six out of 22 TaCKX genes were found polymorphic, forming 14 distinct haplotypes. Functional markers were developed and validated for all the polymorphic TaCKX genes. Four specific haplotypes, i.e., TaCKX2A_2, TaCKX4A_2, TaCKX5A_3, and TaCKX9A_2, were found significantly associated with high thousand-grain weight (TGW) and short plant height (PH) in Chinese wheat micro-core collection (MCC) and GWAS open population (GWAS-OP), whereas TaCKX1B_2 in GWAS-OP and TaCKX11A_3 in MCC were significantly associated with high TGW and short PH. The mean values of TGW and PH for cumulative favorable haplotypes from chromosome 3A, i.e., TaCKX2A_2, TaCKX4A_2, and TaCKX5A_3, were significantly higher as compared to the cumulative unfavored haplotypes, and the change was additive in manner. Frequency distribution analysis revealed that since the 1960s, the frequency of the favorable haplotypes and TGW has gradually increased in Chinese wheat cultivars. Expression profiling in the seed tissue excised at 2, 4, 6, and 8 days after anthesis depicted that the favorable haplotypes are significantly less expressive as compared to the unfavored haplotypes. We conclude that the functional markers developed in this study can be used to select the favorable haplotypes of TaCKX genes in wheat marker-assisted breeding programs.
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http://dx.doi.org/10.1007/s00122-020-03661-6DOI Listing
November 2020

TubZIP28, a novel bZIP family transcription factor from Triticum urartu, and TabZIP28, its homologue from Triticum aestivum, enhance starch synthesis in wheat.

New Phytol 2020 06 8;226(5):1384-1398. Epub 2020 Feb 8.

Agronomy College, National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, 15 Longzihu College District, Zhengzhou, 450046, China.

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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http://dx.doi.org/10.1111/nph.16435DOI Listing
June 2020

Natural variations in the promoter of Awn Length Inhibitor 1 (ALI-1) are associated with awn elongation and grain length in common wheat.

Plant J 2020 03 4;101(5):1075-1090. Epub 2019 Dec 4.

State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.

Wheat awn plays a vital role in photosynthesis, grain production, and drought tolerance. However, the systematic identification or cloning of genes controlling wheat awn development is seldom reported. Here, we conducted a genome-wide association study (GWAS) with 364 wheat accessions and identified 26 loci involved in awn length development, including previously characterized B1, B2, Hd, and several rice homologs. The dominant awn suppressor B1 was fine mapped to a 125-kb physical interval, and a C H zinc finger protein Awn Length Inhibitor 1 (ALI-1) was confirmed to be the underlying gene of the B1 locus through the functional complimentary test with native awnless allele. ALI-1 expresses predominantly in the developing spike of awnless individuals, transcriptionally suppressing downstream genes. ALI-1 reduces cytokinin content and simultaneously restrains cytokinin signal transduction, leading to a stagnation of cell proliferation and reduction of cell numbers during awn development. Polymorphisms of four single nucleotide polymorphisms (SNPs) located in ALI-1 promoter region are diagnostic for the B1/b1 genotypes, and these SNPs are associated with awn length (AL), grain length (GL) and thousand-grain weight (TGW). More importantly, ali-1 was observed to increase grain length in wheat, which is a valuable attribute of awn on grain weight, aside from photosynthesis. Therefore, ALI-1 pleiotropically regulates awn and grain development, providing an alternative for grain yield improvement and addressing future climate changes.
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http://dx.doi.org/10.1111/tpj.14575DOI Listing
March 2020

Unraveling the genetic architecture of grain size in einkorn wheat through linkage and homology mapping and transcriptomic profiling.

J Exp Bot 2019 09;70(18):4671-4688

State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology/Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing, China.

Understanding the genetic architecture of grain size is a prerequisite to manipulating grain development and improving the potential crop yield. In this study, we conducted a whole genome-wide quantitative trait locus (QTL) mapping of grain-size-related traits by constructing a high-density genetic map using 109 recombinant inbred lines of einkorn wheat. We explored the candidate genes underlying QTLs through homologous analysis and RNA sequencing. The high-density genetic map spanned 1873 cM and contained 9937 single nucleotide polymorphism markers assigned to 1551 bins on seven chromosomes. Strong collinearity and high genome coverage of this map were revealed by comparison with physical maps of wheat and barley. Six grain size-related traits were surveyed in five environments. In total, 42 QTLs were identified; these were assigned to 17 genomic regions on six chromosomes and accounted for 52.3-66.7% of the phenotypic variation. Thirty homologous genes involved in grain development were located in 12 regions. RNA sequencing identified 4959 genes differentially expressed between the two parental lines. Twenty differentially expressed genes involved in grain size development and starch biosynthesis were mapped to nine regions that contained 26 QTLs, indicating that the starch biosynthesis pathway plays a vital role in grain development in einkorn wheat. This study provides new insights into the genetic architecture of grain size in einkorn wheat; identification of the underlying genes enables understanding of grain development and wheat genetic improvement. Furthermore, the map facilitates quantitative trait mapping, map-based cloning, genome assembly, and comparative genomics in wheat taxa.
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http://dx.doi.org/10.1093/jxb/erz247DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6760303PMC
September 2019

A wheat dominant dwarfing line with Rht12, which reduces stem cell length and affects gibberellic acid synthesis, is a 5AL terminal deletion line.

Plant J 2019 03 15;97(5):887-900. Epub 2019 Jan 15.

The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.

Dwarfing and semi-dwarfing are important agronomic traits that have great potential for the improvement of wheat yields. Rht12, a dominant gibberellic acid (GA)-responsive dwarfing gene from the gamma-ray-induced wheat mutant Karcagi 522M7K, is located in the long arm of chromosome 5A, which is closely linked with the locus Xwmc410. Rht12 is likely an ideal gene for GA biosynthesis and deactivation research in common wheat. However, information on the Rht12 locus and sequence is lacking. In this study, Rht12 significantly shortened stem cell length and decreased GA biosynthetic components. Using bulked segregant RNA-Seq, wheat 660k single nucleotide polymorphism chip detection, and newly developed simple sequence repeat markers, Rht12 was mapped to a 11.21-Mb region at the terminal end of chromosome 5AL, and was found to be closely linked with the Xw5ac207SSR marker with a 10.73-Mb fragment deletion in all of the homologous dwarfing plants. Transcriptome analyses of the remaining 483-kb region showed significantly higher expression of the TraesCS5A01G543100 gene encoding the GA metabolic enzyme GA 2-β-dioxygenase in dwarfing plants than in high stalk plants, suggesting that Rht12 reduces plant height by activating TaGA2ox-A14. Taken together, our findings will promote cloning and functional studies of Rht12 in common wheat.
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http://dx.doi.org/10.1111/tpj.14168DOI Listing
March 2019

Low molecular weight glutenin subunit gene composition at Glu-D3 loci of Aegilops tauschii and common wheat and a further view of wheat evolution.

Theor Appl Genet 2018 Dec 17;131(12):2745-2763. Epub 2018 Sep 17.

State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 1 West Beichen Road, Chaoyang District, Beijing, 100101, China.

Key Message: A comprehensive comparison of LMW-GS genes between Ae. tauschii and its progeny common wheat. Low molecular weight glutenin subunits (LMW-GSs) are determinant of wheat flour processing quality. However, the LMW-GS gene composition in Aegilops tauschii, the wheat D genome progenitor, has not been comprehensively elucidated and the impact of allohexaploidization on the Glu-D3 locus remains elusive. In this work, using the LMW-GS gene molecular marker system and the full-length gene-cloning method, LMW-GS genes at the Glu-D3 loci of 218 Ae. tauschii and 173 common wheat (Triticum aestivum L.) were characterized. Each Ae. tauschii contained 11 LMW-GS genes, and the whole collection was divided into 25 haplotypes (AeH01-AeH25). The Glu-D3 locus in common wheat lacked the LMW-GS genes D3-417, D3-507 and D3-552, but shared eight genes of identical open reading frame (ORF) sequences when compared to that of Ae. tauschii. Therefore, the allohexaploidization induces deletions, but exerts no influence on LMW-GS gene coding sequences at the Glu-D3 locus. 92.17% Ae. tauschii had 7-9 LMW-GSs, more than the six subunits in common wheat. The haplotypes AeH16, AeH20 and AeH23 of Ae. tauschii ssp. strangulate distributed in southeastern Caspian Iran were the main putative D genome donor of common wheat. These results facilitate the utilization of the Ae. tauschii glutenin gene resources and the understanding of wheat evolution.
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http://dx.doi.org/10.1007/s00122-018-3188-1DOI Listing
December 2018

Diversity, distribution of Puroindoline genes and their effect on kernel hardness in a diverse panel of Chinese wheat germplasm.

BMC Plant Biol 2017 Sep 20;17(1):158. Epub 2017 Sep 20.

State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 1 West Beichen Road, Chaoyang District, Beijing, 100101, China.

Background: Kernel hardness, which has great influence on the end-use properties of common wheat, is mainly controlled by Puroindoline genes, Pina and Pinb. Using EcoTILLING platform, we herein investigated the allelic variations of Pina and Pinb genes and their association with the Single Kernel Characterization System (SKCS) hardness index in a diverse panel of wheat germplasm.

Results: The kernel hardness varied from 1.4 to 102.7, displaying a wide range of hardness index. In total, six Pina and nine Pinb alleles resulting in 15 genotypes were detected in 1787 accessions. The most common alleles are the wild type Pina-D1a (90.4%) and Pina-D1b (7.4%) for Pina, and Pinb-D1b (43.6%), Pinb-D1a (41.1%) and Pinb-D1p (12.8%) for Pinb. All the genotypes have hard type kernel hardness of SKCS index (>60.0), except the wild types of Pina and Pinb combination (Pina-D1a/Pinb-D1a). The most frequent genotypes in Chinese and foreign cultivars was Pina-D1a/Pinb-D1b (46.3 and 39.0%, respectively) and in Chinese landraces was Pina-D1a/Pinb-D1a (54.2%). The frequencies of hard type accessions are increasing from 35.5% in the region IV, to 40.6 and 61.4% in the regions III and II, and then to 77.0% in the region I, while those of soft type are accordingly decreasing along with the increase of latitude. Varieties released after 2000 in Beijing, Hebei, Shandong and Henan have higher average kernel hardness index than that released before 2000.

Conclusion: The kernel hardness in a diverse panel of Chinese wheat germplasm revealed an increasing of kernel hardness generally along with the latitude across China. The wild type Pina-D1a and Pinb-D1a, and one Pinb mutant (Pinb-D1b) are the most common alleles of six Pina and nine Pinb alleles, and a new double null genotype (Pina-D1x/Pinb-D1ah) possessed relatively high SKCS hardness index. More hard type varieties were released in recent years with different prevalence of Pin-D1 combinations in different regions. This work would benefit the understanding of the selection and molecular processes of kernel hardness across China and different breeding stages, and provide useful information for the improvement of wheat quality in China.
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http://dx.doi.org/10.1186/s12870-017-1101-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5607584PMC
September 2017

Cloning and Functional Analysis of MADS-box Genes, and , from a Wheat K-type Cytoplasmic Male Sterile Line.

Front Plant Sci 2017 20;8:1081. Epub 2017 Jun 20.

The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of SciencesBeijing, China.

Wheat ( L.) is a major crop worldwide. The utilization of heterosis is a promising approach to improve the yield and quality of wheat. Although there have been many studies on wheat cytoplasmic male sterility, its mechanism remains unclear. In this study, we identified two MADS-box genes from a wheat K-type cytoplasmic male sterile (CMS) line using homology-based cloning. These genes were localized on wheat chromosomes 3A and 3B and named and , respectively. Analysis of and expression patterns in leaves, spikes, roots, and stems of Chinese Spring wheat determined using quantitative RT-PCR revealed different expression levels in different tissues. had relatively high expression levels in leaves and spikes, but low levels in roots, while had relatively high expression levels in spikes and lower expression in roots, stems, and leaves. Both genes showed downregulation during the mononucleate to trinucleate stages of pollen development in the maintainer line. In contrast, upregulation of was observed in the CMS line. The transcript levels of the two genes were clearly higher in the CMS line compared to the maintainer line at the trinucleate stage. Overexpression of and in resulted in phenotypes with earlier reproductive development, premature mortality, and abnormal buds, stamens, and stigmas. Overexpression of and gives rise to mutants with many deformities. Silencing and in a fertile wheat line using the virus-induced gene silencing (VIGS) method resulted in plants with green and yellow striped leaves, emaciated spikes, and decreased selfing seed set rates. These results demonstrate that and may play a role in male sterility in the wheat CMS line.
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http://dx.doi.org/10.3389/fpls.2017.01081DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5476771PMC
June 2017

Genetic diversity, population structure and marker-trait associations for agronomic and grain traits in wild diploid wheat Triticum urartu.

BMC Plant Biol 2017 07 1;17(1):112. Epub 2017 Jul 1.

State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 1 West Beichen Road, Chaoyang District, Beijing, 100101, China.

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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http://dx.doi.org/10.1186/s12870-017-1058-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5494140PMC
July 2017

Development of an integrated linkage map of einkorn wheat and its application for QTL mapping and genome sequence anchoring.

Theor Appl Genet 2017 Jan 22;130(1):53-70. Epub 2016 Sep 22.

State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing, 100101, People's Republic of China.

Key Message: An integrated genetic map was constructed for einkorn wheat A genome and provided valuable information for QTL mapping and genome sequence anchoring. Wheat is one of the most widely grown food grain crops in the world. The construction of a genetic map is a key step to organize biologically or agronomically important traits along the chromosomes. In the present study, an integrated linkage map of einkorn wheat was developed using 109 recombinant inbred lines (RILs) derived from an inter sub-specific cross, KT1-1 (T. monococcum ssp. boeoticum) × KT3-5 (T. monococcum ssp. monococcum). The map contains 926 molecular markers assigned to seven linkage groups, and covers 1,377 cM with an average marker interval of 1.5 cM. A quantitative trait locus (QTL) analysis of five agronomic traits identified 16 stable QTL on all seven chromosomes, except 6A. The total phenotypic variance explained by these stable QTL using multiple regressions varied across environments from 8.8 to 87.1 % for days to heading, 24.4-63.0 % for spike length, 48.2-79.6 % for spikelet number per spike, 13.1-48.1 % for plant architecture, and 12.2-26.5 % for plant height, revealing that much of the RIL phenotypic variation had been genetically dissected. Co-localizations of closely linked QTL for different traits were frequently observed, especially on 3A and 7A. The QTL on 3A, 5A and 7A were closely associated with Eps-A 3, Vrn1 and Vrn3 loci, respectively. Furthermore, this genetic map facilitated the anchoring of 237 T. urartu scaffolds onto seven chromosomes with a physical length of 26.15 Mb. This map and the QTL data provide valuable genetic information to dissect important agronomic and developmental traits in diploid wheat and contribute to the genetic ordering of the genome assembly.
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http://dx.doi.org/10.1007/s00122-016-2791-2DOI Listing
January 2017

Molecular Characterization of Three GIBBERELLIN-INSENSITIVE DWARF2 Homologous Genes in Common Wheat.

PLoS One 2016 21;11(6):e0157642. Epub 2016 Jun 21.

The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.

F-box protein is a core component of the ubiquitin E3 ligase SCF complex and is involved in the gibberellin (GA) signaling pathway. To elucidate the molecular mechanism of GA signaling in wheat, three homologous GIBBERELLIN-INSENSITIVE DWARF2 genes, TaGID2s, were isolated from the Chinese Spring wheat variety. A subcellular localization assay in onion epidermal cells and Arabidopsis mesophyll protoplasts showed that TaGID2s are localized in the nuclei. The expression profiles using quantitative real-time polymerase chain reaction showed that TaGID2s were downregulated by GA3. The interaction between TaGID2s and TSK1 (homologous to ASK1) in yeast indicated that TaGID2s might function as a component of an E3 ubiquitin-ligase SCF complex. Yeast two-hybrid assays showed that a GA-independent interaction occurred between three TaGID2s and RHT-A1a, RHT-B1a, and RHT-D1a. Furthermore, TaGID2s interact with most RHT-1s, such as RHT-B1h, RHT-B1i, RHT-D1e, RHT-D1f, etc., but cannot interact with RHT-B1b or RHT-B1e, which have a stop codon in the DELLA motif, resulting in a lack of a GRAS domain. In addition, RHT-B1k has a frame-shift mutation in the VHIID motif leading to loss of the LHRII motif in the GRAS domain and RHT-D1h has a missense mutation in the LHRII motif. These results indicate that TaGID2s, novel positive regulators of the GA response, recognize RHT-1s in the LHRII motif resulting in poly-ubiquitination and degradation of the DELLA protein.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0157642PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4915692PMC
July 2017

Characterization and Genetic Analysis of a Novel Light-Dependent Lesion Mimic Mutant, lm3, Showing Adult-Plant Resistance to Powdery Mildew in Common Wheat.

PLoS One 2016 13;11(5):e0155358. Epub 2016 May 13.

College of Agronomy/The Collaborative Innovation Center of Grain Crops in Henan, Henan Agricultural University, Zhengzhou, China.

Lesion mimics (LMs) that exhibit spontaneous disease-like lesions in the absence of pathogen attack might confer enhanced plant disease resistance to a wide range of pathogens. The LM mutant, lm3 was derived from a single naturally mutated individual in the F1 population of a 3-1/Jing411 cross, backcrossed six times with 3-1 as the recurrent parent and subsequently self-pollinated twice. The leaves of young seedlings of the lm3 mutant exhibited small, discrete white lesions under natural field conditions. The lesions first appeared at the leaf tips and subsequently expanded throughout the entire leaf blade to the leaf sheath. The lesions were initiated through light intensity and day length. Histochemical staining revealed that lesion formation might reflect programmed cell death (PCD) and abnormal accumulation of reactive oxygen species (ROS). The chlorophyll content in the mutant was significantly lower than that in wildtype, and the ratio of chlorophyll a/b was increased significantly in the mutant compared with wildtype, indicating that lm3 showed impairment of the biosynthesis or degradation of chlorophyll, and that Chlorophyll b was prone to damage during lesion formation. The lm3 mutant exhibited enhanced resistance to wheat powdery mildew fungus (Blumeria graminis f. sp. tritici; Bgt) infection, which was consistent with the increased expression of seven pathogenesis-related (PR) and two wheat chemically induced (WCI) genes involved in the defense-related reaction. Genetic analysis showed that the mutation was controlled through a single partially dominant gene, which was closely linked to Xbarc203 on chromosome 3BL; this gene was delimited to a 40 Mb region between SSR3B450.37 and SSR3B492.6 using a large derived segregating population and the available Chinese Spring chromosome 3B genome sequence. Taken together, our results provide information regarding the identification of a novel wheat LM gene, which will facilitate the additional fine-mapping and cloning of the gene to understand the mechanism underlying LM initiation and disease resistance in common wheat.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0155358PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866716PMC
July 2017

The 160 bp Insertion in the Promoter of Rht-B1i Plays a Vital Role in Increasing Wheat Height.

Front Plant Sci 2016 16;7:307. Epub 2016 Mar 16.

The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences Beijing, China.

The extensive use of two alleles (Rht-B1b and Rht-D1b) at the Rht-1 locus in wheat allowed dramatic increases in yields, triggering the so-called "Green Revolution." Here, we found that a new natural allelic variation (Rht-B1i) containing a single missense SNP (A614G) in the coding region significantly increased plant height against the genetic background of both Rht-D1a (11.68%) and Rht-D1b (7.89%). To elucidate the molecular mechanism of Rht-B1i, we investigated the promoter region. Sequence analysis showed that the Rht-B1i promoter could be divided into two classes depending on the presence or absence of a specific 160 bp insertion: Rht-B1i-1 (with the 160 bp insertion) and Rht-B1i-2 (without the 160 bp insertion). The promoter of Rht-B1i-1 contained 32 more possible cis-acting elements than Rht-B1a, including a unique auxin response element AUXREPSIAA4. Quantitative RT-PCR analysis indicated that the 160 bp insertion is likely to promote the transcription of the Rht-B1i-1 gene. The coleoptile lengths of wheat varieties treated with IAA, GA3, and IAA/GA3, combined with the histochemical staining of transgenic Arabidopsis containing the Rht-B1i-1 promoter, showed that the height-increasing effect of Rht-B1i-1 may be due to the synergistic action of IAA and GA3. These results augment our understanding of the regulatory mechanisms of Rht-1 in wheat and provide new genetic resources for wheat improvement.
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http://dx.doi.org/10.3389/fpls.2016.00307DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4792873PMC
March 2016

Genome-, Transcriptome- and Proteome-Wide Analyses of the Gliadin Gene Families in Triticum urartu.

PLoS One 2015 1;10(7):e0131559. Epub 2015 Jul 1.

College of Agronomy/The Collaborative Innovation Center of Grain Crops in Henan, Henan Agricultural University, Zhengzhou, China.

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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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0131559PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4489009PMC
April 2016

Composition, variation, expression and evolution of low-molecular-weight glutenin subunit genes in Triticum urartu.

BMC Plant Biol 2015 Feb 28;15:68. Epub 2015 Feb 28.

Background: 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.

Results: 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.

Conclusions: 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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http://dx.doi.org/10.1186/s12870-014-0322-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4364320PMC
February 2015

Novel natural allelic variations at the Rht-1 loci in wheat.

J Integr Plant Biol 2013 Nov;55(11):1026-37

The State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing, 100101, China.

Plant height is an important agronomic trait. Dramatic increase in wheat yield during the "green revolution" is mainly due to the widespread utilization of the Reduced height (Rht)-1 gene. We analyzed the natural allelic variations of three homoeologous loci Rht-A1, Rht-B1, and Rht-D1 in Chinese wheat (Triticum aestivum L.) micro-core collections and the Rht-B1/D1 genotypes in over 1,500 bred cultivars and germplasms using a modified EcoTILLING. We identified six new Rht-A1 allelic variations (Rht-A1b-g), eight new Rht-B1 allelic variations (Rht-B1h-o), and six new Rht-D1 allelic variations (Rht-D1e-j). These allelic variations contain single nucleotide polymorphisms (SNPs) or small insertions and deletions in the coding or uncoding regions, involving two frame-shift mutations and 15 missenses. Of which, Rht-D1e and Rht-D1h resulted in the loss of interactions of GID1-DELLA-GID2, Rht-B1i could increase plant height. We found that the Rht-B1h contains the same SNPs and 197 bp fragment insertion as reported in Rht-B1c. Further detection of Rht-B1h in Tibet wheat germplasms and wheat relatives indicated that Rht-B1c may originate from Rht-B1h. These results suggest rich genetic diversity at the Rht-1 loci and provide new resources for wheat breeding.
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http://dx.doi.org/10.1111/jipb.12103DOI Listing
November 2013

Novel insights into the composition, variation, organization, and expression of the low-molecular-weight glutenin subunit gene family in common wheat.

J Exp Bot 2013 Apr 27;64(7):2027-40. Epub 2013 Mar 27.

State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 1 West Beichen Road, Chaoyang District, Beijing 100101, China.

Low-molecular-weight glutenin subunits (LMW-GS), encoded by a complex multigene family, play an important role in the processing quality of wheat flour. Although members of this gene family have been identified in several wheat varieties, the allelic variation and composition of LMW-GS genes in common wheat are not well understood. In the present study, using the LMW-GS gene molecular marker system and the full-length gene cloning method, a comprehensive molecular analysis of LMW-GS genes was conducted in a representative population, the micro-core collections (MCC) of Chinese wheat germplasm. Generally, >15 LMW-GS genes were identified from individual MCC accessions, of which 4-6 were located at the Glu-A3 locus, 3-5 at the Glu-B3 locus, and eight at the Glu-D3 locus. LMW-GS genes at the Glu-A3 locus showed the highest allelic diversity, followed by the Glu-B3 genes, while the Glu-D3 genes were extremely conserved among MCC accessions. Expression and sequence analysis showed that 9-13 active LMW-GS genes were present in each accession. Sequence identity analysis showed that all i-type genes present at the Glu-A3 locus formed a single group, the s-type genes located at Glu-B3 and Glu-D3 loci comprised a unique group, while high-diversity m-type genes were classified into four groups and detected in all Glu-3 loci. These results contribute to the functional analysis of LMW-GS genes and facilitate improvement of bread-making quality by wheat molecular breeding programmes.
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http://dx.doi.org/10.1093/jxb/ert070DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3638834PMC
April 2013

Molecular characterization of three GIBBERELLIN-INSENSITIVE DWARF1 homologous genes in hexaploid wheat.

J Plant Physiol 2013 Mar 20;170(4):432-43. Epub 2012 Dec 20.

The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.

GIBBERELLIN-INSENSITIVE DWARF1 (GID1) functions as a gibberellin (GA) receptor and is a key component in the GA signaling pathway. In this paper, three TaGID1 genes, orthologous to rice OsGID1 (the first identified GA receptor GID1 gene), were isolated from hexaploid wheat using homology cloning. Like OsGID1, the three homologous TaGID1 genes consisted of two exons and one intron. Physical location analyses using nullisomic-tetrasomic and deletion lines derived from the wheat cultivar Chinese Spring revealed that the three homologous TaGID1 genes reside in the chromosome bins 1AL3-0.61-1, 1BL1-0.47-0.69, and 1DL2-0.41-1. Accordingly, they were named TaGID1-A1, TaGID1-B1, and TaGID1-D1, respectively. The expression patterns of the three TaGID1 genes were determined by real-time PCR in various wheat tissues at the heading stage, including flag leaves, young spikes, peduncles, and the third and fourth internodes. The three TaGID1 genes had similar transcript patterns, and all exhibited greater expression in flag leaves than in the other tissues. Moreover, they were all down-regulated after treatment with exogenous gibberellic acid (GA(3)) in young seedlings, suggesting a feedback regulation of TaGID1 in wheat. Yeast two-hybrid assays demonstrated strong interactions between each putative TaGID1 and the wheat DELLA proteins RHT-A1, RHT-B1, and RHT-D1 in the presence of GA(3), and weak interactions in the absence of GA(3) in yeast cells. Furthermore, over-expression of each TaGID1 gene in the Arabidopsis double mutant gid1a/1c partially rescued the dwarf phenotype. These results suggest that the three TaGID1 homologous genes are all functional GA receptor genes in wheat.
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http://dx.doi.org/10.1016/j.jplph.2012.11.010DOI Listing
March 2013

The genes for gibberellin biosynthesis in wheat.

Funct Integr Genomics 2012 Mar 19;12(1):199-206. Epub 2011 Aug 19.

The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.

The gibberellin biosynthesis pathway is well defined in Arabidopsis and features seven key enzymes including ent-copalyl diphosphate synthase (CPS), ent-kaurene synthase (KS), ent-kaurene oxidase (KO), ent-kaurenoic acid oxidase (KAO), GA 20-oxidase, GA 3-oxidase, and GA 2-oxidase. The Arabidopsis genes were used to identify their counterparts in wheat and the TaCPS, TaKS, TaKO, and TaKAO genes were cloned from Chinese Spring wheat. In order to determine their chromosome locations, expression patterns and feedback regulations, three TaCPS genes, three TaKS genes, three TaKO genes, and three TaKAO genes were cloned from Chinese Spring wheat. They are mainly located on chromosomes 7A, 7B, 7D and 2A, 2B and 2D. The expression patterns of TaCPS, TaKS, TaKO, and TaKAO genes in wheat leaves, young spikes, peduncles, the third and forth internodes were investigated using quantitative PCR. The results showed that all the genes were constitutively expressed in wheat, but their relative expression levels varied in different tissues. They were mainly transcribed in stems, secondly in leaves and spikes, and the least in peduncles. Feedback regulation of the TaCPS, TaKS, TaKO, and TaKAO genes was not evident. These results indicate that all the genes and their homologs may play important roles in the developmental processes of wheat, but each of the homologs may function differently in different tissues or during different developmental stages.
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http://dx.doi.org/10.1007/s10142-011-0243-2DOI Listing
March 2012

PCR-based isolation and identification of full-length low-molecular-weight glutenin subunit genes in bread wheat (Triticum aestivum L.).

Theor Appl Genet 2011 Dec 10;123(8):1293-305. Epub 2011 Aug 10.

State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 1 West Beichen Road, Chaoyang District, Beijing 100101, China.

Low-molecular-weight glutenin subunits (LMW-GSs) are encoded by a multi-gene family and are essential for determining the quality of wheat flour products, such as bread and noodles. However, the exact role or contribution of individual LMW-GS genes to wheat quality remains unclear. This is, at least in part, due to the difficulty in characterizing complete sequences of all LMW-GS gene family members in bread wheat. To identify full-length LMW-GS genes, a polymerase chain reaction (PCR)-based method was established, consisting of newly designed conserved primers and the previously developed LMW-GS gene molecular marker system. Using the PCR-based method, 17 LMW-GS genes were identified and characterized in Xiaoyan 54, of which 12 contained full-length sequences. Sequence alignments showed that 13 LMW-GS genes were identical to those found in Xiaoyan 54 using the genomic DNA library screening, and the other four full-length LMW-GS genes were first isolated from Xiaoyan 54. In Chinese Spring, 16 unique LMW-GS genes were isolated, and 13 of them contained full-length coding sequences. Additionally, 16 and 17 LMW-GS genes in Dongnong 101 and Lvhan 328 (chosen from the micro-core collections of Chinese germplasm), respectively, were also identified. Sequence alignments revealed that at least 15 LMW-GS genes were common in the four wheat varieties, and allelic variants of each gene shared high sequence identities (>95%) but exhibited length polymorphism in repetitive regions. This study provides a PCR-based method for efficiently identifying LMW-GS genes in bread wheat, which will improve the characterization of complex members of the LMW-GS gene family and facilitate the understanding of their contributions to wheat quality.
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http://dx.doi.org/10.1007/s00122-011-1667-8DOI Listing
December 2011

Investigation of genetic diversity and population structure of common wheat cultivars in northern China using DArT markers.

BMC Genet 2011 May 11;12:42. Epub 2011 May 11.

The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.

Background: In order to help establish heterotic groups of Chinese northern wheat cultivars (lines), Diversity arrays technology (DArT) markers were used to investigate the genetic diversity and population structure of Chinese common wheat (Triticum aestivum L.).

Results: In total, 1637 of 7000 DArT markers were polymorphic and scored with high confidence among a collection of 111 lines composed mostly of cultivars and breeding lines from northern China. The polymorphism information content (PIC) of DArT markers ranged from 0.03 to 0.50, with an average of 0.40, with P > 80 (reliable markers). With principal-coordinates analysis (PCoA) of DArT data either from the whole genome or from the B-genome alone, all lines fell into one of two major groups reflecting 1RS/1BL type (1RS/1BL and non-1RS/1BL). Evidence of geographic clustering of genotypes was also observed using DArT markers from the A genome. Cluster analysis based on the unweighted pair-group method with algorithmic mean suggested the existence of two subgroups within the non-1RS/1BL group and four subgroups within the 1RS/1BL group. Furthermore, analysis of molecular variance (AMOVA) revealed highly significant (P < 0.001) genetic variance within and among subgroups and among groups.

Conclusion: These results provide valuable information for selecting crossing parents and establishing heterotic groups in the Chinese wheat-breeding program.
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http://dx.doi.org/10.1186/1471-2156-12-42DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3114777PMC
May 2011

Development of a new marker system for identifying the complex members of the low-molecular-weight glutenin subunit gene family in bread wheat (Triticum aestivum L.).

Theor Appl Genet 2011 May 23;122(8):1503-16. Epub 2011 Feb 23.

State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 1 West Beichen Road, Chaoyang District, Beijing, China.

Low-molecular-weight glutenin subunits (LMW-GSs) play an important role in determining the bread-making quality of bread wheat. However, LMW-GSs display high polymorphic protein complexes encoded by multiple genes, and elucidating the complex LMW-GS gene family in bread wheat remains challenging. In the present study, using conventional polymerase chain reaction (PCR) with conserved primers and high-resolution capillary electrophoresis, we developed a new molecular marker system for identifying LMW-GS gene family members. Based on sequence alignment of 13 LMW-GS genes previously identified in the Chinese bread wheat variety Xiaoyan 54 and other genes available in GenBank, PCR primers were developed and assigned to conserved sequences spanning the length polymorphism regions of LMW-GS genes. After PCR amplification, 17 DNA fragments in Xiaoyan 54 were detected using capillary electrophoresis. In total, 13 fragments were identical to previously identified LMW-GS genes, and the other 4 were derived from unique LMW-GS genes by sequencing. This marker system was also used to identify LMW-GS genes in Chinese Spring and its group 1 nulli-tetrasomic lines. Among the 17 detected DNA fragments, 4 were located on chromosome 1A, 5 on 1B, and 8 on 1D. The results suggest that this marker system is useful for large-scale identification of LMW-GS genes in bread wheat varieties, and for the selection of desirable LMW-GS genes to improve the bread-making quality in wheat molecular breeding programmes.
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http://dx.doi.org/10.1007/s00122-011-1550-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3082022PMC
May 2011

New insights into the organization, recombination, expression and functional mechanism of low molecular weight glutenin subunit genes in bread wheat.

PLoS One 2010 Oct 21;5(10):e13548. Epub 2010 Oct 21.

State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.

The bread-making quality of wheat is strongly influenced by multiple low molecular weight glutenin subunit (LMW-GS) proteins expressed in the seeds. However, the organization, recombination and expression of LMW-GS genes and their functional mechanism in bread-making are not well understood. Here we report a systematic molecular analysis of LMW-GS genes located at the orthologous Glu-3 loci (Glu-A3, B3 and D3) of bread wheat using complementary approaches (genome wide characterization of gene members, expression profiling, proteomic analysis). Fourteen unique LMW-GS genes were identified for Xiaoyan 54 (with superior bread-making quality). Molecular mapping and recombination analyses revealed that the three Glu-3 loci of Xiaoyan 54 harbored dissimilar numbers of LMW-GS genes and covered different genetic distances. The number of expressed LMW-GS in the seeds was higher in Xiaoyan 54 than in Jing 411 (with relatively poor bread-making quality). This correlated with the finding of higher numbers of active LMW-GS genes at the A3 and D3 loci in Xiaoyan 54. Association analysis using recombinant inbred lines suggested that positive interactions, conferred by genetic combinations of the Glu-3 locus alleles with more numerous active LMW-GS genes, were generally important for the recombinant progenies to attain high Zeleny sedimentation value (ZSV), an important indicator of bread-making quality. A higher number of active LMW-GS genes tended to lead to a more elevated ZSV, although this tendency was influenced by genetic background. This work provides substantial new insights into the genomic organization and expression of LMW-GS genes, and molecular genetic evidence suggesting that these genes contribute quantitatively to bread-making quality in hexaploid wheat. Our analysis also indicates that selection for high numbers of active LMW-GS genes can be used for improvement of bread-making quality in wheat breeding.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0013548PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2958824PMC
October 2010

Asparagine synthetase gene TaASN1 from wheat is up-regulated by salt stress, osmotic stress and ABA.

J Plant Physiol 2005 Jan;162(1):81-9

Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Chaoyang District, Beijing 100101, People's Republic of China.

Differences in gene expression between salinity stressed and normally grown wheat seedlings were compared by the differential display (DD) technique. One DD-derived cDNA clone was characterized as a partial sequence of the wheat asparagine ynthetase (AS) gene by sequence analysis and homology search of GenBank databases. Two AS genes of wheat, TaASN1 and TaASN2, were further isolated by the RT-PCR approach. Comparison of the deduced polypeptide of TaASN1 and TaASN2 with AS proteins from other organisms revealed several homologous regions, in particular, the conserved glutamine binding sites and Class-II Glutamine amidotransferases domain. The functionality of TaASN1 was demonstrated by complementing an Escherichia coli asparagine auxotroph. TaASN1 transcripts were detected in roots, shoots, anthers and young spikes by RT-PCR analysis. Abundance of TaASN1 mRNA in young spikes and anthers was higher than that in shoots and roots under normal growth conditions. TaASN1 was dramatically induced by salinity, osmotic stress and exogenous abscisic acid (ABA) in wheat seedlings. TaASN2 transcripts were very low in all detected tissues and conditions and were only slightly induced by ABA in roots.
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http://dx.doi.org/10.1016/j.jplph.2004.07.006DOI Listing
January 2005