According to conventional theory, little genomic changes should occur in homozygous and stable amphiploids of the grass family, particularly those involving polyploid wheat as a parent. In the present study, however, ...According to conventional theory, little genomic changes should occur in homozygous and stable amphiploids of the grass family, particularly those involving polyploid wheat as a parent. In the present study, however, extensive genomic changes were detected in two octoploid partial amphiploids of common wheat (Triticum aestivum L.)_wheatgrass (Agropyron intermedium (Host) P.B.=Elytrigia intermedia (Host) Nevski=Thinopyrum intermedium (Host) Barkworth and Dewey), namely Zhong 3 and Zhong 5, by RFLP analysis using 10 low_copy, wheat chromosome_specific sequences and 33 representative homoeologous group_specific sequences as probes. Genomic changes involved loss of wheat hybridization fragment(s) and/or acquisition of new fragment(s). Uniformity of the RFLP patterns among 5 individual plants taken respectively from Zhong 3 and Zhong 5 in two successive generations, suggested that genomic changes probably had occurred in the early few generations after octoploid amphiploid formation, and remained essentially static thereafter. The highly similar RFLP patterns between Zhong 3 and Zhong 5, which had identical genomic constitution but differed from each other due to involvement of different wheat varieties as parents imply that genomic changes were probably not at random. Possible causes for the extensive and rapid genomic changes in the newly formed plant amphiploids, as well as their implications for polyploid genome evolution and breeding application are discussed.展开更多
A breast basic conserved 1 (BBC1) cDNA has been isolated from common wheat (Triticum aestivum L.). Analysis of amino acid sequence derived from the cDNA showed that the wheat BBC1 was highly hydrophilic and rich in al...A breast basic conserved 1 (BBC1) cDNA has been isolated from common wheat (Triticum aestivum L.). Analysis of amino acid sequence derived from the cDNA showed that the wheat BBC1 was highly hydrophilic and rich in alanine, lysine, glutamic acid and arginine residues. The transcription of wheat BBC1 mRNA was regulated by low temperature. Southern blotting analysis showed that BBC1 existed as a small family in common wheat genome.展开更多
In common wheat, insoluble glutenin （IG） is an important fraction of flour glutenin macropolymers, and insoluble glutenin content （IGC） is positively associated with key end-use quality parameters. Here, we presen...In common wheat, insoluble glutenin （IG） is an important fraction of flour glutenin macropolymers, and insoluble glutenin content （IGC） is positively associated with key end-use quality parameters. Here, we present a genetic analysis of the chromosomal loci affecting IGC with the data collected from 90 common wheat varieties cultivated in four environments. Statistical analysis showed that IGC was controlled mainly genetically and influenced by the environment. Among the major genetic components known to affect end-use quality, 1BL/1RS translocation had a significantly negative effect on IGC across all four environments. As to the different alleles of Glu-A1, -B1 and -D1 loci, Glu-Ala, Glu-Blb and Glu-Dld exhibited relatively strong positive effects on IGC in all environments. To identify new loci affecting IGC, association mapping with 1355 DArT markers was conducted. A total of 133 markers were found associated with IGC in two or more environments （P 〈 0.05）, ten of which consistently affected IGC in all four environments. The phenotypic variance explained by the ten markers varied from 4.66% to 8.03%, and their elite alleles performed significantly better than the inferior counterparts in enhancing IGC. Among the ten markers, wPt-3743 and wPt-733835 reflected the action of Glu-D1, and wPt-664972 probably indicated the effect of GIu-A1. The other seven markers, forming three clusters on 2AL. 3BL or 7BL chromosome arms, represented newly identified genetic determinants of IGC. Our work provided novel insights into the genetic control of IGC, which may facilitate wheat end- use quality improvement through molecular breeding in the future.展开更多
Miniature inverted-repeat transposable elements(MITEs) are a type of DNA transposon frequently inserted into promoters, untranslated regions(UTR), introns, or coding sequences of genes. We found a 276-bp tourist-like ...Miniature inverted-repeat transposable elements(MITEs) are a type of DNA transposon frequently inserted into promoters, untranslated regions(UTR), introns, or coding sequences of genes. We found a 276-bp tourist-like MITE insertion in the 3′-UTR of a 16.9 k Da small heat shock protein gene(TaH SP16.9-3A) on chromosome 3A of common wheat. Haplotype analysis revealed two haplotypes, s HSP-W(wild type without MITE insertion) and s HSP-M(mutant with MITE insertion), present in wheat germplasm. Both semiquantitative PCR and quantitative real-time PCR analyses showed increased transcription levels of TaH SP16.9-3A in s HSP-M compared with those of s HSP-W after heat treatment at 42 °C. It appeared that the MITE insertion into the 3′-UTR enhances the transcription of TaH SP16.9-3A.展开更多
Pre-harvest sprouting(PHS) adversely affects wheat quality and yield, and grain color(GC) is associated with PHS resistance. However, the genetic relationship between GC and PHS resistance remains unclear. In this stu...Pre-harvest sprouting(PHS) adversely affects wheat quality and yield, and grain color(GC) is associated with PHS resistance. However, the genetic relationship between GC and PHS resistance remains unclear. In this study, 168 wheat varieties(lines) with significant differences in GC and PHS resistance were genotyped using an Illumina 90K iSelect SNP array. Genome-wide association study(GWAS) based on a mixed linear model showed that 67 marker-trait associations(MTAs) assigned to 29 loci, including 17 potentially novel loci, were significantly associated with GC, which explained 1.1–17.0% of the phenotypic variation. In addition, 100 MTAs belonging to 54 loci, including 31 novel loci, were significantly associated with PHS resistance, which accounted for 1.1–14.7% of the phenotypic variation. Subsequently, two cleaved amplified polymorphic sequences(CAPS) markers, 2B-448 on chromosome 2B and 5B-301 on chromosome 5B,were developed from the representative SNPs of the major common loci Qgc.ahau-2B.3/Qphs.ahau-2B.4controlling GC/PHS resistance and PHS resistance locus Qphs.ahau-5B.4, respectively. Further validation in 171 Chinese mini-core collections confirmed significant correlations of the two CAPS markers with GC and PHS resistance phenotypes under different environments(P<0.05). Furthermore, the wheat public expression database, transcriptomic sequencing, and gene allelic variation analysis identified TraesCS5B02G545100, which encodes glutaredoxin, as a potential candidate gene linked to Qphs.ahau-5B.4. The new CAPS marker CAPS-356 was then developed based on the SNP(T/C) in the coding sequences(CDS) region of TraesCS5B02G545100. The high-density linkage map of the Jing 411/Hongmangchun 21 recombinant inbred lines(RILs) constructed based on specific locus amplified fragment sequencing markers showed that CAPS-356 collocated with a novel QTL for PHS resistance, supporting the role of TraesCS5B02G545100 as the potential candidate gene linked to Qphs.ahau-5B.4. These results provide valuable information for the map-based cloning of Qphs.ahau-5B.4 and breeding of PHS resistant white-grained varieties.展开更多
Agropyron cristatum, a wild relative of common wheat(Triticum aestivum L.), provides many desirable genetic resources for wheat improvement, such as tolerance to cold, drought, and disease. To transfer and utilize the...Agropyron cristatum, a wild relative of common wheat(Triticum aestivum L.), provides many desirable genetic resources for wheat improvement, such as tolerance to cold, drought, and disease. To transfer and utilize these desirable genes, in this study, two wheat-A. cristatum derivatives II-13 and II-23 were identified and analyzed. We found that the number of root tip cell chromosomes was 44 in both II-13 and II-23, but there were four and six P genome chromosomes in II-13 and II-23, respectively, based on genomic in situ hybridization(GISH). The chromosome configurations of II-13 and II-23 were both 2 n=22 II by the meiotic analysis of pollen mother cells(PMCs) at metaphase I, indicating that there were two and three pairs of P chromosomes in II-13 and II-23, respectively. Notably, wheat chromosome 7 D was absent in derivative line II-13 while II-23 lacked chromosomes 4 B and 7 A based on SSR analysis combining fluorescence in situ hybridization(FISH) analysis with p As1 and p Sc119.2 as probes. Chromosomes 2 P and 7 P were detected in both II-13 and II-23. Another pair of P genome chromosomes in II-23 was determined to be 4 P based on expressed-sequences tags-sequence tagged sites(EST-STS) markers specific to A. cristatum and FISH with probes p Ac TRT1 and p Acp CR2. Overall, these results suggest that II-13 was a 7 P(7 D) substitution line with one pair of additional 2 P chromosomes and II-23 was a multiple 4 P(4 B), 7 P(7 A) substitution line with one pair of additional 2 P chromosomes. Moreover, we obtained six alien disomic addition lines and five alien disomic substitution lines by backcrossing. These new materials will allow desirable genes from A. cristatum to be used in common wheat.展开更多
[Objective] This study aimed to investigate the polymorphism of PBF en- coding genes from common wheat Chinese Spring （Triticum aestivum L.）. [Method] Using common wheat Chinese Spring as the experimental material, ...[Objective] This study aimed to investigate the polymorphism of PBF en- coding genes from common wheat Chinese Spring （Triticum aestivum L.）. [Method] Using common wheat Chinese Spring as the experimental material, gene-specific primers were designed and applied to amplify the genomic DNA of Chinese Spring. PCR products were isolated, purified and ligated into the cloning vector. Positive clones were randomly selected for sequencing. A series of softwares including DNAMAN, Signalp, PSIPRED, Nuc_PLoc and MEGA were employed for sequence assembly and alignment, signal peptide prediction, primary and secondary structure prediction, as well as analyses of subcellular location and phylogenetic relationships between the PBF family members in Poaceae. [Result] Twenty-five target sequences were obtained from the genome of hexaploid common wheat Chinese Spring, which were classified into three clusters based on the sequence similarity. SNPs exist at two loci of the subunit, resulting in the change of encoded amino acid residues and affecting the secondary structure of final product encoded. [Conclusion] PBF encoding sequences are extremely conservative in Chinese Spring with certain variations. This study provides theoretical reference to evaluate the expression efficiency of wheat storage proteins.展开更多
Wheat tiller angle(TA)is an important agronomic trait that contributes to grain production by affecting plant architecture.It also plays a crucial role in high-yield wheat breeding.An association panel and a recombina...Wheat tiller angle(TA)is an important agronomic trait that contributes to grain production by affecting plant architecture.It also plays a crucial role in high-yield wheat breeding.An association panel and a recombinant inbred line(RIL)population were used to map quantitative trait loci(QTL)for TA.Results showed that 470 significant SNPs with 10.4%–28.8%phenotypic variance explained(PVE)were detected in four replicates by a genome-wide association study(GWAS).Haplotype analysis showed that the TA_Hap_4B1 locus on chromosome 4B was a major QTL to regulate wheat TA.Ten QTL were totally detected by linkage mapping with the RIL population,and QTA.hau-4B.1 identified in six environments with the PVE of 7.88%–18.82%was a major and stable QTL.A combined analysis demonstrated that both TA_Hap_4B1 and QTA.hau-4B.1 were co-located on the same region.Moreover,QTA.hau-4B.1 was confirmed by bulked segregant RNA-Seq(BSR-Seq)analysis.Phenotypic analysis showed that QTA.hau-4B.1was also closely related to yield traits.Furthermore,Traes CS4B02G049700 was considered as a candidate gene through analysis of gene sequence and expression.This study can be potentially used in cloning key genes modulating wheat tillering and provides valuable genetic resources for improvement of wheat plant architecture.展开更多
The F 1 and F 4 plants of 'synthetic hexaploid wheat/common wheat'crosses and part of their parents were inoculated with Fusarium graminearum to evaluate FHB resistance.The results showed tht the scab resist...The F 1 and F 4 plants of 'synthetic hexaploid wheat/common wheat'crosses and part of their parents were inoculated with Fusarium graminearum to evaluate FHB resistance.The results showed tht the scab resistance in the F 1 varied with the synthetic wheat accessions used as crossing parents.In the F 4,some resistant head lines were generated from the crosses,although their parents had different scab resistance levels.It indicated that synthetic hexaploid wheat are useful in wheat breeding for scab resistance.展开更多
By the modified ISSR-amplification method the comparison of the structural organization of enzyme loci in the initial common wheat cultivars and their genotrophs induced with epimutagens: plant niacin acid and niacin ...By the modified ISSR-amplification method the comparison of the structural organization of enzyme loci in the initial common wheat cultivars and their genotrophs induced with epimutagens: plant niacin acid and niacin acid and its derivatives produced from β-picoline fraction of coal-tar pitch (niacin acid nitrile, isocinchomeronic and benzoic acids) was carried out. It is shown that niacin acid influence causes in genotrophs specific band appearance in PCR-profiles obtained on the DNA of enzyme loci. All these before mentioned epimutagens induced in limits of each genotroph differently directed changes in number and intensity of bands of PCR-profiles.展开更多
The study of PCR-profiles of isozyme loci Me1 and Adh1 in common wheat lines obtained by means of treatment of initial cultivar Alem with detergent Tri-ton X-100 was carried out by the modified ISSR-amplification meth...The study of PCR-profiles of isozyme loci Me1 and Adh1 in common wheat lines obtained by means of treatment of initial cultivar Alem with detergent Tri-ton X-100 was carried out by the modified ISSR-amplification method. It was demonstrated that exposure to Triton X-100 causes changes of PCR-profiles of enzyme loci. The obtained data are suggestive of the role of chromatin and nuclear mem-brane interaction in structural-functional genome organization.展开更多
Non-destructive time-series assessment of chlorophyll content in flag-leaf(FLC)accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to imp...Non-destructive time-series assessment of chlorophyll content in flag-leaf(FLC)accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to improve yield stability under stressed environments.In this study,we employed both unmanned aerial vehicles(UAVs)equipped with red–green–blue(RGB)camera and ground-based SPAD-502 instrument to conduct temporal phenotyping of senescence.A total of 262 recombinant inbred lines derived from the cross of Zhongmai 578/Jimai 22 were evaluated for senescence-related traits across three environments,spanning from heading to 35 d post-anthesis.The manual senescence rate(MSR)was quantified using the FLC and the active accumulated temperature,and UAV derived vegetation index were utilized to assess the stay-green rate(USG)facilitating the identification of senescent and stay-green lines.Results indicated that higher senescence rates significantly impacted grain yield,primarily by influencing thousand-kernel weight,and plant height.Quantitative trait loci(QTL)mapping for FLC,USG,and MSR using the 50K SNP array identified 38 stable loci associated with RGB-based vegetation indices and senescence-related traits:among which 19 loci related to senescence traits from UAV and FLC were consistently detected across at least two growth stages,with nine loci likely representing novel QTL.This study highlights the potential of UAV-based high-throughput phenotyping and phenology in identifying critical loci associated with senescence rates in wheat,validating the relationship between senescence rates and yield-related traits in wheat,offering valuable opportunities for gene discovery and significant applications in breeding programs.展开更多
Powdery mildew is a serious disease caused by Blumeria graminis f.sp.tritici(Bgt)that critically threatens the yield and quality of wheat(Triticum aestivum L.).Using effective powdery mildew resistance genes is the op...Powdery mildew is a serious disease caused by Blumeria graminis f.sp.tritici(Bgt)that critically threatens the yield and quality of wheat(Triticum aestivum L.).Using effective powdery mildew resistance genes is the optimal method for controlling this disease.Against the background of high genetic homogeneity among the modern commercial cultivars that are mainly derived from conventional interbreeding,the resistance genes from wheat relatives have especially prominent advantages.Octoploid triticale,produced from common wheat and rye(Secale cereale L.)through distant hybridization,is a new synthetic species and valuable gene donor for wheat improvement.In this study,we developed the wheat-rye line YT5 through the hybridization of octaploid triticale and two wheat lines.YT5 was confirmed to be a 6RL ditelosomic addition and 1R(1B)substitution line using genomic in situ hybridization(GISH),multicolor fluorescence in situ hybridization(mc-FISH),multicolor GISH(mc-GISH)and molecular marker analysis.Genetic analysis showed that the powdery mildew resistance in YT5 was derived from the rye chromosome arm 6RL.After inoculation with different Bgt isolates at the seedling stage,YT5 had compound reaction patterns with both obvious spores and hypersensitivity,and it gradually became highly resistant until the adult-plant stage,thus showing a resistance response significantly different from the reported Pm genes from rye chromosome 6RL.YT5 also showed promising agronomic performance,so it is expected to be an elite resistance donor for wheat improvement.To promote the transfer of the chromosome arm 6RL of YT5 in marker-assisted selection(MAS)breeding,we selected and verified two 6RL-specific kompetitive allelespecific PCR(KASP)markers that can be applied to efficiently detect this chromosome arm in different wheat backgrounds.展开更多
Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD...Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD, 2n=14). An essential prerequisite for this evolutionary step is that the natural hybrids between tetraploid wheat and diploid Aegilops tauschii can produce relatively many filled seeds which germinated well. In this study, without special techniques, e.g. immature embryo culture, out of 22 Ae. tauschii accessions, the genotype AS60 produced relatively many filled seeds which germinated well. The seed germination percentages in the crosses of Ae. tauschii ×tetraploid wheat, tetraploid wheat× Ae. tauschii and Ae. tauschii ×common wheat were, respectively, 50.0%, 57.1% and 45.5%. It seems that Ae. tauschii accession AS60 has a unique genotype which facilitate hybrid seed development and viability, and which meets with the prerequisite for wheat evolutionary. Furthermore, the significance of this finding for common wheat improvement and evolution was discussed.展开更多
An S-like RNase cDNA had been isolated from common wheat (Triticum aestivum L). The transcription of WRN1 mRNA was down-regulated by natural- and dark-induced senescence. But it was not senile-tissue-specific. As the ...An S-like RNase cDNA had been isolated from common wheat (Triticum aestivum L). The transcription of WRN1 mRNA was down-regulated by natural- and dark-induced senescence. But it was not senile-tissue-specific. As the two key histidine residues were replaced, WRN1 may not be active as RNase. Southern blotting analysis showed that WRN1 exists as one of a small gene family in common wheat genome.展开更多
Common wheat is the major cereal crop that underpins the food safety of China. Both winter wheat and spring wheat are grown on ~24 million ha. This review aims to summarize the current status of wheat production and b...Common wheat is the major cereal crop that underpins the food safety of China. Both winter wheat and spring wheat are grown on ~24 million ha. This review aims to summarize the current status of wheat production and breeding progress in the northern wheat production areas of the country, and to review recently advanced technologies being applied in wheat breeding, including the use of dwarf-male-sterile(DMS) wheat, speed breeding and specialized wheat breeding SNP chips. Crossing is the initial step in most breeding programs. DMS wheat is a convenient tool for large scale production of hybrid seed. Speed breeding or accelerated generation turnover attempts to reduce the time taken in cultivar development. Several different SNP chips are high-throughput, genome-wide genotyping platforms for breeding and research.展开更多
cDNA-AFLP(amplified fragment length polymorphism) is used to isolate genes differentiallyexpressed in salt-stressed and unstressed wheat lines RH8706-49 and H8706-34 derivedfrom a single seed, representing a salt-stre...cDNA-AFLP(amplified fragment length polymorphism) is used to isolate genes differentiallyexpressed in salt-stressed and unstressed wheat lines RH8706-49 and H8706-34 derivedfrom a single seed, representing a salt-stress resistant (SR) and salt-stress sensitive(SS) line, respectively. About 88.1% cDNA fragment are expressed in all the four samples,11.9% are different between the samples. 68 cDNA fragments were cloned, of which 35 weresubject to sequence analysis. Database searches indicate that 11 cDNA fragment show highhomology to known genes, which mainly include proteins related to ion transport, signaltransduction and oxidative stress. The remaining 24 cDNA show no detectable homology toknown genes, suggesting that they probably represent novel genes.展开更多
Understanding the genetic mechanisms for cadmium (Cd) uptake and translocation in common wheat (Triticum aestivum) is of significance in food Cd contamination control. In this study, a diverse panel of 132 wheat culti...Understanding the genetic mechanisms for cadmium (Cd) uptake and translocation in common wheat (Triticum aestivum) is of significance in food Cd contamination control. In this study, a diverse panel of 132 wheat cultivars was collected from the North China Plain. The cultivars were evaluated in terms of their phenotypic variations in response to Cd stress and subjected to a genome-wide association study (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with the phenotypic variations at the seedling stage. Significant phenotypic variations with high heritability were observed among the wheat cultivars exposed to 40 μmol L-1 Cd for the studied traits, including root length (RL), shoot length (SL), root and shoot dry biomasses (RDW and SDW, respectively), root and shoot Cd concentrations (RCD and SCD, respectively), and Cd translocation factor (TF). Mean RCD, SCD, and TF ranged from 1.0 to 33.8, 0.125 to 2.022, and 0.009 to 0.321 mg g-1, respectively. Cluster analysis showed that wheat cultivars with higher RL, SL, RDW, and SDW under Cd stress were able to accumulate more Cd in root, leading to a lower Cd TF. Mixed linear model-based association analysis detected 17 novel significant marker-trait associations (MTAs), four of which were significant at a genome-wide scale. Most of the significant MTAs controlled Cd TF and explained 17.17%–26.47% of the phenotypic variations. Some of the SNP loci were physically close to a reported Cd-related quantitative trait locus or gene on wheat chromosomes. Results of this study provided a list of wheat cultivars with the potential of low Cd accumulation and enriched our knowledge on the genetic basis of Cd uptake and translocation in wheat. Pyramiding breeding of superior alleles detected in this study may additionally reduce Cd accumulation of improved wheat cultivars with excellent agronomic traits.展开更多
Obligate biotrophic fungi cause serious and widespread diseases of crop plants, but are challenging to investigate because they cannot be cultured in vitro. The two economically important groups of biotrophic fungi pa...Obligate biotrophic fungi cause serious and widespread diseases of crop plants, but are challenging to investigate because they cannot be cultured in vitro. The two economically important groups of biotrophic fungi parasitizing wheat are the rust and powdery mildew pathogens, but their obligate biotrophic lifestyles and pathogenicity mechanisms are not well understood at the molecular level. With the advent of next generation sequencing technology, increasing numbers of pathogen genomes are becoming available. Research in plant pathology has entered a new genomics era. This review summarizes recent progress in understanding the biology and pathogenesis of biotrophic fungal pathogens attacking wheat based on pathogen genomics. We particularly focus on the three wheat rust and the powdery mildew fungi in regard to genome sequencing, avirulence gene cloning, effector discovery, and pathogenomics. We predict that coordinated study of both wheat and its pathogens should reveal new insights in biotrophic adaptation, pathogenicity mechanisms,and population dynamics of these fungi that will assist in development of new strategies for breeding wheat varieties with durable resistance.展开更多
Receptor-like cytoplasmic kinases(RLCKs)represent a large family of proteins in plants.In Arabidopsis and rice,several RLCKs in subfamily VII(RLCKs-VII)have been implicated in pathogen-associated molecular pattern-tri...Receptor-like cytoplasmic kinases(RLCKs)represent a large family of proteins in plants.In Arabidopsis and rice,several RLCKs in subfamily VII(RLCKs-VII)have been implicated in pathogen-associated molecular pattern-triggered immunity and basal resistance against bacterial and fungal pathogens.However,little is known about roles of RLCKs-VII of the important crop common wheat(Triticum aestivum)in immune responses.Here,we isolated a RLCK-VII-encoding gene from wheat,designated as TaRLCK1B,and investigated its role in host immune response to infection of a necrotrophic fungus Rhizoctonia cerealis that is a major pathogen of sharp eyespot,a destructive disease of wheat.RNA-sequencing and RT-qPCR analyses showed that transcriptional level of TaRLCK1B was significantly higher in sharp eyespot-resistant wheat cultivars than in susceptible wheat cultivars.The gene transcription was rapidly and markedly elevated in the resistant wheat cultivars by R.cerealis infection.The TaRLCK1B protein was closely related to OsRLCK176,a rice resistance-related RLCKs-VII,with 84.03%identity.Virus-induced gene silencing plus wheat response to R.cerealis assay results indicated that silencing of TaRLCK1 impaired resistance to R.cerealis.Meantime,silencing of TaRLCK1 significantly elevated both the content of H2 O2(a major kind of reactive oxygen species,ROS)and the transcriptional level of the ROS-generating enzyme-encoding gene RBOH,but repressed the expression of the ROS-scavenging enzyme-encoding gene CAT1 at 18 hours after inoculation(hai)with R.cerealis.Taken together,these data suggested that TaRLCK1B was required for the early immune response of wheat to R.cerealis through modulating ROS signaling in wheat.展开更多
文摘According to conventional theory, little genomic changes should occur in homozygous and stable amphiploids of the grass family, particularly those involving polyploid wheat as a parent. In the present study, however, extensive genomic changes were detected in two octoploid partial amphiploids of common wheat (Triticum aestivum L.)_wheatgrass (Agropyron intermedium (Host) P.B.=Elytrigia intermedia (Host) Nevski=Thinopyrum intermedium (Host) Barkworth and Dewey), namely Zhong 3 and Zhong 5, by RFLP analysis using 10 low_copy, wheat chromosome_specific sequences and 33 representative homoeologous group_specific sequences as probes. Genomic changes involved loss of wheat hybridization fragment(s) and/or acquisition of new fragment(s). Uniformity of the RFLP patterns among 5 individual plants taken respectively from Zhong 3 and Zhong 5 in two successive generations, suggested that genomic changes probably had occurred in the early few generations after octoploid amphiploid formation, and remained essentially static thereafter. The highly similar RFLP patterns between Zhong 3 and Zhong 5, which had identical genomic constitution but differed from each other due to involvement of different wheat varieties as parents imply that genomic changes were probably not at random. Possible causes for the extensive and rapid genomic changes in the newly formed plant amphiploids, as well as their implications for polyploid genome evolution and breeding application are discussed.
文摘A breast basic conserved 1 (BBC1) cDNA has been isolated from common wheat (Triticum aestivum L.). Analysis of amino acid sequence derived from the cDNA showed that the wheat BBC1 was highly hydrophilic and rich in alanine, lysine, glutamic acid and arginine residues. The transcription of wheat BBC1 mRNA was regulated by low temperature. Southern blotting analysis showed that BBC1 existed as a small family in common wheat genome.
基金supported by the Ministry of Science and Technology of China (Grant No. 2014CB138104)Chinese Academy of Sciences (Grant No. XDA08010302)the National Science Foundation of China (Grant No. 31371611)
文摘In common wheat, insoluble glutenin （IG） is an important fraction of flour glutenin macropolymers, and insoluble glutenin content （IGC） is positively associated with key end-use quality parameters. Here, we present a genetic analysis of the chromosomal loci affecting IGC with the data collected from 90 common wheat varieties cultivated in four environments. Statistical analysis showed that IGC was controlled mainly genetically and influenced by the environment. Among the major genetic components known to affect end-use quality, 1BL/1RS translocation had a significantly negative effect on IGC across all four environments. As to the different alleles of Glu-A1, -B1 and -D1 loci, Glu-Ala, Glu-Blb and Glu-Dld exhibited relatively strong positive effects on IGC in all environments. To identify new loci affecting IGC, association mapping with 1355 DArT markers was conducted. A total of 133 markers were found associated with IGC in two or more environments （P 〈 0.05）, ten of which consistently affected IGC in all four environments. The phenotypic variance explained by the ten markers varied from 4.66% to 8.03%, and their elite alleles performed significantly better than the inferior counterparts in enhancing IGC. Among the ten markers, wPt-3743 and wPt-733835 reflected the action of Glu-D1, and wPt-664972 probably indicated the effect of GIu-A1. The other seven markers, forming three clusters on 2AL. 3BL or 7BL chromosome arms, represented newly identified genetic determinants of IGC. Our work provided novel insights into the genetic control of IGC, which may facilitate wheat end- use quality improvement through molecular breeding in the future.
基金supported by the China Agricultural University Graduate Research and Innovation Project (kycx09019)
文摘Miniature inverted-repeat transposable elements(MITEs) are a type of DNA transposon frequently inserted into promoters, untranslated regions(UTR), introns, or coding sequences of genes. We found a 276-bp tourist-like MITE insertion in the 3′-UTR of a 16.9 k Da small heat shock protein gene(TaH SP16.9-3A) on chromosome 3A of common wheat. Haplotype analysis revealed two haplotypes, s HSP-W(wild type without MITE insertion) and s HSP-M(mutant with MITE insertion), present in wheat germplasm. Both semiquantitative PCR and quantitative real-time PCR analyses showed increased transcription levels of TaH SP16.9-3A in s HSP-M compared with those of s HSP-W after heat treatment at 42 °C. It appeared that the MITE insertion into the 3′-UTR enhances the transcription of TaH SP16.9-3A.
基金supported by grants from the University Synergy Innovation Program of Anhui Province,China(GXXT-2021-058)the National Natural Science Foundation of China(Joint Fund Projects,U20A2033)+3 种基金the Natural Science Foundation of Anhui Province,China(2108085MC98)the Jiangsu Collaborative Innovation Center for Modern Crop Production,China(JCIC-MCP)the key scientific and technological breakthroughs of Anhui Province(2021d06050003)the joint key project of improved wheat variety of Anhui Province,China(21803003).
文摘Pre-harvest sprouting(PHS) adversely affects wheat quality and yield, and grain color(GC) is associated with PHS resistance. However, the genetic relationship between GC and PHS resistance remains unclear. In this study, 168 wheat varieties(lines) with significant differences in GC and PHS resistance were genotyped using an Illumina 90K iSelect SNP array. Genome-wide association study(GWAS) based on a mixed linear model showed that 67 marker-trait associations(MTAs) assigned to 29 loci, including 17 potentially novel loci, were significantly associated with GC, which explained 1.1–17.0% of the phenotypic variation. In addition, 100 MTAs belonging to 54 loci, including 31 novel loci, were significantly associated with PHS resistance, which accounted for 1.1–14.7% of the phenotypic variation. Subsequently, two cleaved amplified polymorphic sequences(CAPS) markers, 2B-448 on chromosome 2B and 5B-301 on chromosome 5B,were developed from the representative SNPs of the major common loci Qgc.ahau-2B.3/Qphs.ahau-2B.4controlling GC/PHS resistance and PHS resistance locus Qphs.ahau-5B.4, respectively. Further validation in 171 Chinese mini-core collections confirmed significant correlations of the two CAPS markers with GC and PHS resistance phenotypes under different environments(P<0.05). Furthermore, the wheat public expression database, transcriptomic sequencing, and gene allelic variation analysis identified TraesCS5B02G545100, which encodes glutaredoxin, as a potential candidate gene linked to Qphs.ahau-5B.4. The new CAPS marker CAPS-356 was then developed based on the SNP(T/C) in the coding sequences(CDS) region of TraesCS5B02G545100. The high-density linkage map of the Jing 411/Hongmangchun 21 recombinant inbred lines(RILs) constructed based on specific locus amplified fragment sequencing markers showed that CAPS-356 collocated with a novel QTL for PHS resistance, supporting the role of TraesCS5B02G545100 as the potential candidate gene linked to Qphs.ahau-5B.4. These results provide valuable information for the map-based cloning of Qphs.ahau-5B.4 and breeding of PHS resistant white-grained varieties.
基金supported by the National Key Research and Development Program of China (2016YFD0100102)
文摘Agropyron cristatum, a wild relative of common wheat(Triticum aestivum L.), provides many desirable genetic resources for wheat improvement, such as tolerance to cold, drought, and disease. To transfer and utilize these desirable genes, in this study, two wheat-A. cristatum derivatives II-13 and II-23 were identified and analyzed. We found that the number of root tip cell chromosomes was 44 in both II-13 and II-23, but there were four and six P genome chromosomes in II-13 and II-23, respectively, based on genomic in situ hybridization(GISH). The chromosome configurations of II-13 and II-23 were both 2 n=22 II by the meiotic analysis of pollen mother cells(PMCs) at metaphase I, indicating that there were two and three pairs of P chromosomes in II-13 and II-23, respectively. Notably, wheat chromosome 7 D was absent in derivative line II-13 while II-23 lacked chromosomes 4 B and 7 A based on SSR analysis combining fluorescence in situ hybridization(FISH) analysis with p As1 and p Sc119.2 as probes. Chromosomes 2 P and 7 P were detected in both II-13 and II-23. Another pair of P genome chromosomes in II-23 was determined to be 4 P based on expressed-sequences tags-sequence tagged sites(EST-STS) markers specific to A. cristatum and FISH with probes p Ac TRT1 and p Acp CR2. Overall, these results suggest that II-13 was a 7 P(7 D) substitution line with one pair of additional 2 P chromosomes and II-23 was a multiple 4 P(4 B), 7 P(7 A) substitution line with one pair of additional 2 P chromosomes. Moreover, we obtained six alien disomic addition lines and five alien disomic substitution lines by backcrossing. These new materials will allow desirable genes from A. cristatum to be used in common wheat.
基金Supported by National Natural Science Foundation of China(30900896)Special Fund for the Construction of Modern Agricultural Technology System(NYCYTX-001)Cyrus Tang Breeding Fund(A212020912)~~
文摘[Objective] This study aimed to investigate the polymorphism of PBF en- coding genes from common wheat Chinese Spring （Triticum aestivum L.）. [Method] Using common wheat Chinese Spring as the experimental material, gene-specific primers were designed and applied to amplify the genomic DNA of Chinese Spring. PCR products were isolated, purified and ligated into the cloning vector. Positive clones were randomly selected for sequencing. A series of softwares including DNAMAN, Signalp, PSIPRED, Nuc_PLoc and MEGA were employed for sequence assembly and alignment, signal peptide prediction, primary and secondary structure prediction, as well as analyses of subcellular location and phylogenetic relationships between the PBF family members in Poaceae. [Result] Twenty-five target sequences were obtained from the genome of hexaploid common wheat Chinese Spring, which were classified into three clusters based on the sequence similarity. SNPs exist at two loci of the subunit, resulting in the change of encoded amino acid residues and affecting the secondary structure of final product encoded. [Conclusion] PBF encoding sequences are extremely conservative in Chinese Spring with certain variations. This study provides theoretical reference to evaluate the expression efficiency of wheat storage proteins.
基金funded by the National Natural Science Foundation of China(31971947 and 32072057)Henan Major Science and Technology Projects(201300110800,201300111600)Key Scientific and Technological Project of Henan Province(222102110026)。
文摘Wheat tiller angle(TA)is an important agronomic trait that contributes to grain production by affecting plant architecture.It also plays a crucial role in high-yield wheat breeding.An association panel and a recombinant inbred line(RIL)population were used to map quantitative trait loci(QTL)for TA.Results showed that 470 significant SNPs with 10.4%–28.8%phenotypic variance explained(PVE)were detected in four replicates by a genome-wide association study(GWAS).Haplotype analysis showed that the TA_Hap_4B1 locus on chromosome 4B was a major QTL to regulate wheat TA.Ten QTL were totally detected by linkage mapping with the RIL population,and QTA.hau-4B.1 identified in six environments with the PVE of 7.88%–18.82%was a major and stable QTL.A combined analysis demonstrated that both TA_Hap_4B1 and QTA.hau-4B.1 were co-located on the same region.Moreover,QTA.hau-4B.1 was confirmed by bulked segregant RNA-Seq(BSR-Seq)analysis.Phenotypic analysis showed that QTA.hau-4B.1was also closely related to yield traits.Furthermore,Traes CS4B02G049700 was considered as a candidate gene through analysis of gene sequence and expression.This study can be potentially used in cloning key genes modulating wheat tillering and provides valuable genetic resources for improvement of wheat plant architecture.
文摘The F 1 and F 4 plants of 'synthetic hexaploid wheat/common wheat'crosses and part of their parents were inoculated with Fusarium graminearum to evaluate FHB resistance.The results showed tht the scab resistance in the F 1 varied with the synthetic wheat accessions used as crossing parents.In the F 4,some resistant head lines were generated from the crosses,although their parents had different scab resistance levels.It indicated that synthetic hexaploid wheat are useful in wheat breeding for scab resistance.
文摘By the modified ISSR-amplification method the comparison of the structural organization of enzyme loci in the initial common wheat cultivars and their genotrophs induced with epimutagens: plant niacin acid and niacin acid and its derivatives produced from β-picoline fraction of coal-tar pitch (niacin acid nitrile, isocinchomeronic and benzoic acids) was carried out. It is shown that niacin acid influence causes in genotrophs specific band appearance in PCR-profiles obtained on the DNA of enzyme loci. All these before mentioned epimutagens induced in limits of each genotroph differently directed changes in number and intensity of bands of PCR-profiles.
文摘The study of PCR-profiles of isozyme loci Me1 and Adh1 in common wheat lines obtained by means of treatment of initial cultivar Alem with detergent Tri-ton X-100 was carried out by the modified ISSR-amplification method. It was demonstrated that exposure to Triton X-100 causes changes of PCR-profiles of enzyme loci. The obtained data are suggestive of the role of chromatin and nuclear mem-brane interaction in structural-functional genome organization.
基金funded by the National Key Research and Development Program of China(2022ZD0115703)the National Natural Science Foundation of China(32372196)+1 种基金the Beijing Joint Research Program for Germplasm Innovation and New Variety Breeding(G20220628002)National Natural Science Foundation of China(32250410307)。
文摘Non-destructive time-series assessment of chlorophyll content in flag-leaf(FLC)accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to improve yield stability under stressed environments.In this study,we employed both unmanned aerial vehicles(UAVs)equipped with red–green–blue(RGB)camera and ground-based SPAD-502 instrument to conduct temporal phenotyping of senescence.A total of 262 recombinant inbred lines derived from the cross of Zhongmai 578/Jimai 22 were evaluated for senescence-related traits across three environments,spanning from heading to 35 d post-anthesis.The manual senescence rate(MSR)was quantified using the FLC and the active accumulated temperature,and UAV derived vegetation index were utilized to assess the stay-green rate(USG)facilitating the identification of senescent and stay-green lines.Results indicated that higher senescence rates significantly impacted grain yield,primarily by influencing thousand-kernel weight,and plant height.Quantitative trait loci(QTL)mapping for FLC,USG,and MSR using the 50K SNP array identified 38 stable loci associated with RGB-based vegetation indices and senescence-related traits:among which 19 loci related to senescence traits from UAV and FLC were consistently detected across at least two growth stages,with nine loci likely representing novel QTL.This study highlights the potential of UAV-based high-throughput phenotyping and phenology in identifying critical loci associated with senescence rates in wheat,validating the relationship between senescence rates and yield-related traits in wheat,offering valuable opportunities for gene discovery and significant applications in breeding programs.
基金supported by the National Key Research and Development Program of China(2021YFD1200600)the National Natural Science Foundation of China(32272105).
文摘Powdery mildew is a serious disease caused by Blumeria graminis f.sp.tritici(Bgt)that critically threatens the yield and quality of wheat(Triticum aestivum L.).Using effective powdery mildew resistance genes is the optimal method for controlling this disease.Against the background of high genetic homogeneity among the modern commercial cultivars that are mainly derived from conventional interbreeding,the resistance genes from wheat relatives have especially prominent advantages.Octoploid triticale,produced from common wheat and rye(Secale cereale L.)through distant hybridization,is a new synthetic species and valuable gene donor for wheat improvement.In this study,we developed the wheat-rye line YT5 through the hybridization of octaploid triticale and two wheat lines.YT5 was confirmed to be a 6RL ditelosomic addition and 1R(1B)substitution line using genomic in situ hybridization(GISH),multicolor fluorescence in situ hybridization(mc-FISH),multicolor GISH(mc-GISH)and molecular marker analysis.Genetic analysis showed that the powdery mildew resistance in YT5 was derived from the rye chromosome arm 6RL.After inoculation with different Bgt isolates at the seedling stage,YT5 had compound reaction patterns with both obvious spores and hypersensitivity,and it gradually became highly resistant until the adult-plant stage,thus showing a resistance response significantly different from the reported Pm genes from rye chromosome 6RL.YT5 also showed promising agronomic performance,so it is expected to be an elite resistance donor for wheat improvement.To promote the transfer of the chromosome arm 6RL of YT5 in marker-assisted selection(MAS)breeding,we selected and verified two 6RL-specific kompetitive allelespecific PCR(KASP)markers that can be applied to efficiently detect this chromosome arm in different wheat backgrounds.
文摘Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD, 2n=14). An essential prerequisite for this evolutionary step is that the natural hybrids between tetraploid wheat and diploid Aegilops tauschii can produce relatively many filled seeds which germinated well. In this study, without special techniques, e.g. immature embryo culture, out of 22 Ae. tauschii accessions, the genotype AS60 produced relatively many filled seeds which germinated well. The seed germination percentages in the crosses of Ae. tauschii ×tetraploid wheat, tetraploid wheat× Ae. tauschii and Ae. tauschii ×common wheat were, respectively, 50.0%, 57.1% and 45.5%. It seems that Ae. tauschii accession AS60 has a unique genotype which facilitate hybrid seed development and viability, and which meets with the prerequisite for wheat evolutionary. Furthermore, the significance of this finding for common wheat improvement and evolution was discussed.
文摘An S-like RNase cDNA had been isolated from common wheat (Triticum aestivum L). The transcription of WRN1 mRNA was down-regulated by natural- and dark-induced senescence. But it was not senile-tissue-specific. As the two key histidine residues were replaced, WRN1 may not be active as RNase. Southern blotting analysis showed that WRN1 exists as one of a small gene family in common wheat genome.
基金Financial support provided by the National Key Research and Development Program of China (2017YFD0101000)the Agricultural Science and Technology Innovation Program is acknowledged
文摘Common wheat is the major cereal crop that underpins the food safety of China. Both winter wheat and spring wheat are grown on ~24 million ha. This review aims to summarize the current status of wheat production and breeding progress in the northern wheat production areas of the country, and to review recently advanced technologies being applied in wheat breeding, including the use of dwarf-male-sterile(DMS) wheat, speed breeding and specialized wheat breeding SNP chips. Crossing is the initial step in most breeding programs. DMS wheat is a convenient tool for large scale production of hybrid seed. Speed breeding or accelerated generation turnover attempts to reduce the time taken in cultivar development. Several different SNP chips are high-throughput, genome-wide genotyping platforms for breeding and research.
基金supported by the National Natural Science Foudation of China(30070471)the Natural Science Foundation of Hebei Province(301103).
文摘cDNA-AFLP(amplified fragment length polymorphism) is used to isolate genes differentiallyexpressed in salt-stressed and unstressed wheat lines RH8706-49 and H8706-34 derivedfrom a single seed, representing a salt-stress resistant (SR) and salt-stress sensitive(SS) line, respectively. About 88.1% cDNA fragment are expressed in all the four samples,11.9% are different between the samples. 68 cDNA fragments were cloned, of which 35 weresubject to sequence analysis. Database searches indicate that 11 cDNA fragment show highhomology to known genes, which mainly include proteins related to ion transport, signaltransduction and oxidative stress. The remaining 24 cDNA show no detectable homology toknown genes, suggesting that they probably represent novel genes.
基金supported by the Hebei Science Fund for Distinguished Young Scholars,China(No.D2018503005)the National Key Research and Development Program of China(No.2018YFD0800306)the CAS Preside nfs In ternational Fellowship In itiative Fund(No.2018PB0084).
文摘Understanding the genetic mechanisms for cadmium (Cd) uptake and translocation in common wheat (Triticum aestivum) is of significance in food Cd contamination control. In this study, a diverse panel of 132 wheat cultivars was collected from the North China Plain. The cultivars were evaluated in terms of their phenotypic variations in response to Cd stress and subjected to a genome-wide association study (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with the phenotypic variations at the seedling stage. Significant phenotypic variations with high heritability were observed among the wheat cultivars exposed to 40 μmol L-1 Cd for the studied traits, including root length (RL), shoot length (SL), root and shoot dry biomasses (RDW and SDW, respectively), root and shoot Cd concentrations (RCD and SCD, respectively), and Cd translocation factor (TF). Mean RCD, SCD, and TF ranged from 1.0 to 33.8, 0.125 to 2.022, and 0.009 to 0.321 mg g-1, respectively. Cluster analysis showed that wheat cultivars with higher RL, SL, RDW, and SDW under Cd stress were able to accumulate more Cd in root, leading to a lower Cd TF. Mixed linear model-based association analysis detected 17 novel significant marker-trait associations (MTAs), four of which were significant at a genome-wide scale. Most of the significant MTAs controlled Cd TF and explained 17.17%–26.47% of the phenotypic variations. Some of the SNP loci were physically close to a reported Cd-related quantitative trait locus or gene on wheat chromosomes. Results of this study provided a list of wheat cultivars with the potential of low Cd accumulation and enriched our knowledge on the genetic basis of Cd uptake and translocation in wheat. Pyramiding breeding of superior alleles detected in this study may additionally reduce Cd accumulation of improved wheat cultivars with excellent agronomic traits.
基金supported by the National Basic Research Program of China (2013CB127700)National Natural ScienceFoundation of China (31371882, 31401693)the 111 Project of the Ministry of Education of China (B07049)
文摘Obligate biotrophic fungi cause serious and widespread diseases of crop plants, but are challenging to investigate because they cannot be cultured in vitro. The two economically important groups of biotrophic fungi parasitizing wheat are the rust and powdery mildew pathogens, but their obligate biotrophic lifestyles and pathogenicity mechanisms are not well understood at the molecular level. With the advent of next generation sequencing technology, increasing numbers of pathogen genomes are becoming available. Research in plant pathology has entered a new genomics era. This review summarizes recent progress in understanding the biology and pathogenesis of biotrophic fungal pathogens attacking wheat based on pathogen genomics. We particularly focus on the three wheat rust and the powdery mildew fungi in regard to genome sequencing, avirulence gene cloning, effector discovery, and pathogenomics. We predict that coordinated study of both wheat and its pathogens should reveal new insights in biotrophic adaptation, pathogenicity mechanisms,and population dynamics of these fungi that will assist in development of new strategies for breeding wheat varieties with durable resistance.
基金This study was funded by the Natural Science Foundation of China(31771789)the National Key Project for Research on Transgenic Biology,China(2016ZX08002-001-004)+1 种基金Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2018QNRC001)The authors are very grateful to Prof.Jia Jizeng(ICS,CAAS)for providing the RIL population and Prof.Yu Jinfeng(Shandong Agricultural University,Shandong)for providing R.cerealis strain WK207.
文摘Receptor-like cytoplasmic kinases(RLCKs)represent a large family of proteins in plants.In Arabidopsis and rice,several RLCKs in subfamily VII(RLCKs-VII)have been implicated in pathogen-associated molecular pattern-triggered immunity and basal resistance against bacterial and fungal pathogens.However,little is known about roles of RLCKs-VII of the important crop common wheat(Triticum aestivum)in immune responses.Here,we isolated a RLCK-VII-encoding gene from wheat,designated as TaRLCK1B,and investigated its role in host immune response to infection of a necrotrophic fungus Rhizoctonia cerealis that is a major pathogen of sharp eyespot,a destructive disease of wheat.RNA-sequencing and RT-qPCR analyses showed that transcriptional level of TaRLCK1B was significantly higher in sharp eyespot-resistant wheat cultivars than in susceptible wheat cultivars.The gene transcription was rapidly and markedly elevated in the resistant wheat cultivars by R.cerealis infection.The TaRLCK1B protein was closely related to OsRLCK176,a rice resistance-related RLCKs-VII,with 84.03%identity.Virus-induced gene silencing plus wheat response to R.cerealis assay results indicated that silencing of TaRLCK1 impaired resistance to R.cerealis.Meantime,silencing of TaRLCK1 significantly elevated both the content of H2 O2(a major kind of reactive oxygen species,ROS)and the transcriptional level of the ROS-generating enzyme-encoding gene RBOH,but repressed the expression of the ROS-scavenging enzyme-encoding gene CAT1 at 18 hours after inoculation(hai)with R.cerealis.Taken together,these data suggested that TaRLCK1B was required for the early immune response of wheat to R.cerealis through modulating ROS signaling in wheat.
