Grain yield in cereal crops is a complex trait controlled by multiple genes and influenced by developmental processes and environment. Here we report the effects of alleles Rht8 and Ppd-D1 a on plant height, time to h...Grain yield in cereal crops is a complex trait controlled by multiple genes and influenced by developmental processes and environment. Here we report the effects of alleles Rht8 and Ppd-D1 a on plant height, time to heading, and grain yield and its component traits. Association analysis and quantitative trait locus mapping using phenotypic data from 15 environments led to the following conclusions. First, both Rht8 and Ppd-D1 a reduce plant height. However, Ppd-D1 a but not Rht8 causes earlier heading.Second, both Rht8 and Ppd-D1 a promote grain yield and affect component traits. Their combined effects are substantially larger than those conferred by either allele alone.Third, promotion of grain yield by Rht8 and Ppd-D1 a is through increasing fertile spikelet number. We speculate that Rht8 and Ppd-D1 a act independently and additively in control of plant height, grain yield and yield component. Combination of the two alleles is desirable for adjusting plant height and enhancing grain yield and abiotic stress tolerance.展开更多
Thousand-kernel weight(TKW)is a measure of grain weight,a target of wheat breeding.The object of this study was to fine-map a stable quantitative trait loci(QTL)for TKW and identify its candidate gene in a recombinant...Thousand-kernel weight(TKW)is a measure of grain weight,a target of wheat breeding.The object of this study was to fine-map a stable quantitative trait loci(QTL)for TKW and identify its candidate gene in a recombinant inbred line(RIL)population derived from the cross of Kenong 9204(KN9204)and Jing411(J411).On a high-density genetic linkage map,24,26 and 25 QTL were associated with TKW,kernel length(KL),and kernel width(KW),respectively.A major and stable QTL,QTkw-2D,was mapped to an8.3 cM interval on chromosome arm 2DL.By saturation of polymorphic markers in its target region,QTkw-2D was confined to a 9.13 Mb physical interval using a secondary mapping population derived from a residually heterozygous line(F6:7).This interval was further narrowed to 2.52 Mb using QTkw-2D near-isogenic lines(NILs).NILs~(KN9204)had higher fresh and dry weights than NILsJ411at various grain-filling stages.The TKW and KW of NILs~(KN9204)were much higher than those of NILsJ411in field trials.By comparison of both DNA sequence and expression between KN9204 and J411,TraesCS2D02G460300.1(TraesKN2D01HG49350)was assigned as a candidate gene for QTkw-2D.This was confirmed by RNA sequencing(RNA-seq)of QTkw-2D NILs.These results provide the basis of map-based cloning of QTkw-2D,and DNA markers linked to the candidate gene may be used in marker-assisted selection.展开更多
Thinopyrum intermedium and barley are two close relatives of wheat and carry many genes that are potentially valuable for the improvement of various wheat traits. In this study we created wheat double substitution lin...Thinopyrum intermedium and barley are two close relatives of wheat and carry many genes that are potentially valuable for the improvement of various wheat traits. In this study we created wheat double substitution lines by hybridizing different wheat–Th. intermedium and wheat–barley disomic alien substitution lines, with the aim of using genes in Th. intermedium and barley for wheat breeding and investigating the genetic behavior of alien chromosomes and their wheat homoeologs. As expected, we obtained two types of wheat double substitution lines,2D2Ai#2(2B)2H( A) and 2A2 Ai#2(2B)2H(2D), in which different group 2 wheat chromosomes were replaced by barley chromosome 2 H and Th. intermedium chromosome 2Ai#2. The new materials were characterized using molecular markers, genomic in situ hybridization(GISH), and fluorescent in situ hybridization(FISH). GISH and FISH experiments revealed that the double substitution lines harbor 42 chromosomes including 38 wheat chromosomes, a pair of barley chromosomes, and a pair of Th. intermedium chromosomes. Analysis using specific DNA markers showed that two pairs of wheat homoeologous group 2 chromosomes in the new lines were substituted by a pair of 2H and a pair of 2Ai#2 chromosomes. Chromosome 2H showed a higher transmission rate than 2Ai#2, and both chromosomes were preferentially transmitted between generations via female gametes. Evaluation of botanic and agronomic traits demonstrated that,compared with their parents, the new lines showed similar growth habits and plant type but differences in plant height, flowering date, and self-fertility. Cytological observations using different probes suggested that the double substitution lines showed nearly normal genetic behavior before and during meiosis. The novel substitution lines can potentially be used in wheat meiosis research and breeding programs.展开更多
Some haplotypes of the sucrose synthase gene TaSus1 are associated with thousand-grain weight(TGW)in wheat(Triticum aestivum L.).However,no mutations have been identified within the gene to test this association.The e...Some haplotypes of the sucrose synthase gene TaSus1 are associated with thousand-grain weight(TGW)in wheat(Triticum aestivum L.).However,no mutations have been identified within the gene to test this association.The effects of TaSus1 on grain number per spike(GNS)also are largely unknown.Our previous genome-wide association study identified TaSus-A1 as a candidate gene controlling fertile spikelet number per spike(FSN).In the present study,we generated two independent mutants for the three TaSus1 homoeologs by CRISPR/Cas9-mediated genome editing.The triple mutants displayed lower FSN,GNS,grain number per spikelet(GNST),and TGW than wild-type plants.In 306 hexaploid wheat accessions,two single-nucleotide polymorphisms in TaSus-A1 contributed differently to GNS.Introgression of the two alleles into a wheat genetic background confirmed their effects.The alleles differed in geographical distribution among the accessions.展开更多
AtbHLH29 of Arabidopsis, encoding a bHLH protein, reveals a high similarity to the tomato FER which is proposed as a transcriptional regulator involved in controlling the iron deficiency responses and the iron uptake ...AtbHLH29 of Arabidopsis, encoding a bHLH protein, reveals a high similarity to the tomato FER which is proposed as a transcriptional regulator involved in controlling the iron deficiency responses and the iron uptake in tomato. For identification of its biological functions, AtbHLH29 was introduced into the genome of the tomato FER mutant T3238fer mediated by Agrobacterium tumefaciencs. Transgenic plants were regenerated and the stable integration of AtbHLH29 into their genomes was confirmed by Southern hybridization. Molecular analysis demonstrated that expression of the exogenous AtbHLH29 of Arabidopsis in roots of the FER mutant T3238fer enabled to complement the defect functions of FER. The transgenic plants regained the ability to activate the whole iron deficiency responses and showed normal growth as the wild type under iron-limiting stress. Our transformation data demonstrate that AtbHLH29 is a functional ortholog of the tomato FER and can completely replace FER in controlling the effective iron acquisition in tomato. Except of iron, FER protein was directly or indirectly involved in manganese homeostasis due to that loss functions of FER in T3238fer resulted in strong reduction of Mn content in leaves and the defect function on Mn accumulation in leaves was complemented by expression of AtbHLH29 in the transgenic plants. Identification of the similar biological functions of FER and AtbHLH29, which isolated from two systematically wide-diverged “strategy I” plants, suggests that FER might be a universal gene presented in all strategy I plants in controlling effective iron acquisition system in roots.展开更多
Common wheat is an important and widely cultivated food crop throughout the world.Much progress has been made in regard to wheat genome sequencing in the last decade.Starting from the sequencing of single chromosomes/...Common wheat is an important and widely cultivated food crop throughout the world.Much progress has been made in regard to wheat genome sequencing in the last decade.Starting from the sequencing of single chromosomes/chromosome arms whole genome sequences of common wheat and its diploid and tetraploid ancestors have been decoded along with the development of sequencing and assembling technologies. In this review, we give a brief summary on international progress in wheat genome sequencing, and mainly focus on reviewing the effort and contributions made by Chinese scientists.展开更多
Stripe rust(yellow rust), caused by Puccinia striiformis f. sp. tritici(PST),is one of the most devastating fungal diseases in common wheat(Triticum aestivum L.) in China and worldwide. Resistance breeding is the most...Stripe rust(yellow rust), caused by Puccinia striiformis f. sp. tritici(PST),is one of the most devastating fungal diseases in common wheat(Triticum aestivum L.) in China and worldwide. Resistance breeding is the most effective strategy to control diseases in crop plants. Chinese wheat lines Mengmai 58 and Huaiyang 1 are highly resistant to PST race CYR34(V26) at the adult plant stage. To genetically map the underlying resistance genes we developed segregating populations by crossing Mengmai 58 and Huaiyang 1 with the susceptible cultivar Nongda 399. The stripe rust resistances in Mengmai 58 and Huaiyang 1 were both controlled by single dominant genes, provisionally designated YrMM58 and YrHY1, respectively. Bulked segregant RNA-Seq(BSR-Seq) analysis showed that YrMM58 and YrHY1 were located in the same distal ~16 Mb region on chromosome 2 AS.Comparative genomics analysis with the physical map of Aegilops tauschii proved useful for developing additional markers to saturate the genetic linkage map. YrMM58 and YrHY1 were mapped to the distal end of chromosome arm 2 AS, with the closest marker WGGB148 being 7.7 cM and 3.8 cM from the resistance gene, which was considered to be Yr17. These markers can be used in marker-assisted selection.展开更多
Wheat is the most widely cultivated staple food crop, and multiple types of food derivatives are processed and consumed globally. Wheat grain quality(WGQ) is central to food processing and nutritional value, and is a ...Wheat is the most widely cultivated staple food crop, and multiple types of food derivatives are processed and consumed globally. Wheat grain quality(WGQ) is central to food processing and nutritional value, and is a decisive factor for consumer acceptance and commercial value of wheat cultivars. Hence, improvement in WGQ traits is top priority for both conventional and molecular wheat breeding. In this review we will focus on two important WGQ traits, grain milling and end-use, and will summarize recent progress in China. Chinese scientists have invested substantial effort in molecular genetic and genomic analysis of these traits and their effects on end-use properties. The insights and resources generated have contributed to the understanding and improvement of these traits. As high-quality genomics information and powerful genome engineering tools are becoming available for wheat, more fundamental breakthroughs in dissecting the molecular and genomic basis of WGQ are expected. China will strive to make further significant contributions to the study and improvement of WGQ in the genomics era.展开更多
Powdery mildew,caused by Blumeria graminis f.sp.tritici(Bgt),is one of the most damaging diseases to wheat in the world.The cultivation of resistant varieties of wheat is essential for controlling the powdery mildew e...Powdery mildew,caused by Blumeria graminis f.sp.tritici(Bgt),is one of the most damaging diseases to wheat in the world.The cultivation of resistant varieties of wheat is essential for controlling the powdery mildew epidemic.Wheat landraces are important resources of resistance to many diseases.Mapping powdery mildew resistance genes from wheat landraces will promote the development of new varieties with disease resistance.The Chinese wheat landrace Baiyouyantiao possesses characteristic of disease resistance to powdery mildew.To identify the resistance gene in this landrace,Baiyouyantiao was crossed with the susceptible cultivar Jingshuang 16 and seedlings of parents and F_1,BC_1,F_2,and F_(2:3) were tested with Bgt isolate E09.The genetic results showed that the resistance of Baiyouyantiao to E09 was controlled by a single recessive gene,tentatively designated Pm BYYT.An Illumina wheat 90K single-nucleotide polymorphism(SNP)array was applied to screen polymorphisms between F_2-resistant and F_2-susceptible DNA bulks for identifying the chromosomal location of Pm BYYT.A high percentage of polymorphic SNPs between the resistant and susceptible DNA bulks was found on chromosome 7B,indicating that Pm BYYT may be located on this chromosome.A genetic linkage map of Pm BYYT consisting of two simple sequence repeat markers and eight SNP markers was developed.The two flanking markers were SNP markers W7BL-8 and W7BL-15,with genetic distances of 3 and 2.9 c M,respectively.The results of this study demonstrated the rapid characterization of a wheat disease resistance gene and SNP marker development using the 90K SNP assay.The flanking markers of gene Pm BYYT will benefit marker-assisted selection(MAS)and map-based cloning in breeding wheat cultivars with powdery mildew resistance.展开更多
The TaGS3 homoeologous genes(homoeologs)located on chromosomes 7 A,4 A,and7 D in hexaploid wheat were cloned.Relative expression analysis of the three Ta GS3 homoeologs revealed that the expression levels of TaGS3-4 A...The TaGS3 homoeologous genes(homoeologs)located on chromosomes 7 A,4 A,and7 D in hexaploid wheat were cloned.Relative expression analysis of the three Ta GS3 homoeologs revealed that the expression levels of TaGS3-4 A and TaGS3-7 D in developing grains were higher than that of TaGS3-7 A.Genetic evidence showed that Ta GS3 was a negative regulator of grain weight and grain size.Fifteen polymorphic sites and five haplotypes were detected in TaGS3-4 A.Two molecular markers were developed to distinguish the five haplotypes.Association analysis using 260 accessions from Chinese wheat mini-core collection(MCC)indicated that TaGS3-4 A affected thousand grain weight(TGW)and grain length(GL).HAP-4 A-1 and HAP-4 A-2 were favorable haplotypes that increased TGW and GL and had undergone strong selection during domestication of wheat.In addition,interaction of the TaGS3-4 A and TaGS3-7 D homoeologs had significant additive effects on the grain traits.Hap-4 A-1/Hap-7 D-2 was the best haplotype combination in increasing TGW and GL.The frequencies and geographic distributions of favorable TaGS3 haplotypes among 1388 wheat accessions from worldwide sources provided clues for selection of yield-related traits.Our findings demonstrated that TaGS3-4 A had significant effects on TGW and GL.Marker-assisted selection of HAP-4 A-1/2 combined with HAP-7 D-2 has potential to increase wheat yields.展开更多
Grain size is one of the most important agronomic components of grain yield. Grain length, width and thickness are controlled by multiple quantitative trait loci(QTLs). To understand genetic basis of large grain shape...Grain size is one of the most important agronomic components of grain yield. Grain length, width and thickness are controlled by multiple quantitative trait loci(QTLs). To understand genetic basis of large grain shape and explore the beneficial alleles for grain size improvement, we perform QTL analysis using an F2 population derived from a cross between the japonica variety Beilu 129(BL129, wide and thick grain) and the elite indica variety Huazhan(HZ, narrow and long grain). A total number of eight major QTLs are detected on three different chromosomes. QTLs for grain width(q GW), grain thickness(q GT), brown grain width(q BGW), and brown grain thickness(q BGT) explained 7 7.67, 36.24, 89.63, and 39.41% of total phenotypic variation, respectively. The large grain rice variety BL129 possesses the beneficial alleles of GW2 and q SW5/GW5, which have been known to control grain width and weight, indicating that the accumulation of the beneficial alleles causes large grain shape in BL129. Further results reveal that the rare gw2 allele from BL129 increases grain width, thickness and weight of the elite indica variety Huazhan, which is used as a parental line in hybrid rice breeding. Thus, our findings will help breeders to carry out molecular design breeding on rice grain size and shape.展开更多
Plants use a sophisticated immune system to perceive pathogen infection and activate immune responses in a tightly controlled manner.In barley,Hv WRKY2 acts as a repressor in barley disease resistance to the powdery m...Plants use a sophisticated immune system to perceive pathogen infection and activate immune responses in a tightly controlled manner.In barley,Hv WRKY2 acts as a repressor in barley disease resistance to the powdery mildew fungus,Blumeria graminis f.sp.hordei(Bgh).However,the molecular features of Hv WRKY2 in its DNA-binding and repressor functions,as well as its target genes,are uncharacterized.We show that the W-box binding of Hv WRKY2 requires an intact WRKY domain and an upstream sequence of~75 amino acids,and the Hv WRKY2 W-box binding activity is linked to its repressor function in disease resistance.Chromatin immunoprecipitation(ChIP)-seq analysis identified HvCEBiP,a putative chitin receptor gene,as a target gene of Hv WRKY2 in overexpressing transgenic barley plants.ChIP-qPCR and Electrophoretic Mobility Shift Assay(EMSA)verified the direct binding of Hv WRKY2 to a W-boxcontaining sequence in the HvCEBiP promoter.Hv CEBiP positively regulates resistance against Bgh in barley.Our findings suggest that Hv WRKY2 represses barley basal immunity by directly targeting pathogen-associated molecular pattern(PAMP)recognition receptor genes,suggesting that Hv CEBiP and likely chitin signaling function in barley PAMP-triggered immune responses to Bgh infection.展开更多
Reduced plant height is one of the most important traits related to lodging resistance and crop yield. The use of reduced height genes has been one of the main features in breeding modern high-yielding wheat varieties...Reduced plant height is one of the most important traits related to lodging resistance and crop yield. The use of reduced height genes has been one of the main features in breeding modern high-yielding wheat varieties with less lodging. A spontaneous dwarf mutant DD399 was identified in a high yielding, gibberellic acid(GA)-insensitive, lodging-resistant variety Nongda 399(ND399). Significant differences in upper internode lengths between mutant DD399 and wild type ND399 were caused by reduced cell elongation. The plant height of ND399 × DD399 F_(1) hybrids was intermediate between the parents, indicating incomplete dominance or a dose–response effect of a reduced height gene. Plant height showed continuous distribution in the F_(2) population, and segregation distortion was observed among the 2292 F_(2:3) progenies. The reduced height mutation was characterized by Illumina 90 K iSelect SNP genotyping and bulked segregant RNA-Seq(BSR-Seq) analysis of the segregating population. A concentrated cluster of polymorphic SNPs associated with the reduced height phenotype was detected in the distal region of chromosome arm 2 BL. Co-segregation of reduced height phenotype with the clustered markers revealed a 36 Mb terminal deletion of chromosome 2 BL in mutant DD399.展开更多
Awns play an important role in seed dispersal and photosynthesis of spikes.Three major awn inhibitors(Hd,B1,and B2)are reported in wheat.However,the molecular mechanism underlying awnlessness remained unknown until re...Awns play an important role in seed dispersal and photosynthesis of spikes.Three major awn inhibitors(Hd,B1,and B2)are reported in wheat.However,the molecular mechanism underlying awnlessness remained unknown until recently.In this study,we identified two F8 recombinant inbred lines(RILs)that were segregating for awn length.In order to identify the causal gene for awn length in the heterozygous inbred families(HIFs),SNPs were called from RNA sequencing(RNA-Seq)data for HIF-derived progenies with long and short awns.SNPs between long and short awn plants were evenly distributed on chromosomes(chr)other than chromosome 5 A.SNPs on chr 5 A were clustered in a region distal 688 Mb on the long arm,where inhibitor B1 was located.This suggested that B1 was the causal segregating locus.We precisely mapped B1 to^1 Mb region using two HIF-derived families.Considering that the lines segregated for long,intermediate and short awn phenotypes we speculated that B1 should have a dosage effect on awn length.Two differentially expressed genes(DEGs)located in the candidate region were regarded as candidate genes for B1,because the molecular expression pattern was consistent with the phenotype.HIFs with long and short awns showed no difference on grain yield and other agronomic traits.展开更多
The foundation parents play key roles in the genetic improvement of both yield potential and end-use quality in wheat.Characterizing the genetic basis that underlies certain beneficial traits in the foundation parents...The foundation parents play key roles in the genetic improvement of both yield potential and end-use quality in wheat.Characterizing the genetic basis that underlies certain beneficial traits in the foundation parents will provide theoretical reference for molecular breeding by a design approach.‘Kenong 9204’(KN9204)is a candidate foundation parent characterized by ideotype,high yield potential,and particularly high nitrogen fertilizer utilization.To better understand the genetic basis of its high yield potential,high throughput whole-genome re-sequencing(10×)was performed on KN9204,its parental lines and its derivatives.A high-resolution genetic composition map of KN9204 was constructed,which showed the parental origin of the favorable genomic segments based on the identification of excellent yield-related quantitative trait loci(QTL)from a bi-parental mapping population.Xiaoyan 693(XY693),a wheat–Thinopyrum ponticum partial amphidiploid,contributed a great deal to the high yield potential of KN9204,and three major stable QTLs from XY693 were fine mapped.The transmissibility of key genomic segments from KN9204 to its derivatives were delineated,indicating that haplotype blocks containing beneficial gene combinations were conserved along with directional selection by breeders.Evidence for selection sweeps in the breeding programs was identified.This study provides a theoretical reference for the breeding of high-yield wheat varieties by a molecular design approach.展开更多
The spike architecture of wheat plays a crucial role in determining grain number,making it a key trait for optimization in wheat breeding programs.In this study,we used a multi-omic approach to analyze the transcripto...The spike architecture of wheat plays a crucial role in determining grain number,making it a key trait for optimization in wheat breeding programs.In this study,we used a multi-omic approach to analyze the transcriptome and epigenome profiles of the young spike at eight developmental stages,revealing co-ordinated changes in chromatin accessibility and H3K27me3 abundance during the flowering transition.We constructed a core transcriptional regulatory network(TRN)that drives wheat spike formation and experimentally validated a multi-layer regulatorymodule involving TaSPL15,TaAGLG1,and TaFUL2.By integrating the TRN with genome-wide association studies,we identified 227 transcription factors,including 42 with known functions and 185 with unknown functions.Further investigation of 61 novel transcription factors using multiple homozygous mutant lines revealed 36 transcription factors that regulate spike architecture or flowering time,such as TaMYC2-A1,TaMYB30-A1,and TaWRKY37-A1.Of particular interest,TaMYB30-A1,downstream of and repressed by WFzP,was found to regulate fertile spikelet number.Notably,the excellent haplotype of TaMYB30-A1,which contains a C allele at the WFzP binding site,was enriched during wheat breeding improvement in China,leading to improved agronomic traits.Finally,we constructed a free and open access Wheat Spike Multi-Omic Database(http://39.98.48.156:8800/#/).Our study identifies novel and high-confidence regulators and offers an effective strategy for dissecting the genetic basis of wheat spike development,with practical value forwheat breeding.展开更多
Ever since the concept of"plant cell totipotency"was first proposed in the early twentieth century,plant regeneration has been a major focus of study.Regeneration-mediated organogenesis and genetic transform...Ever since the concept of"plant cell totipotency"was first proposed in the early twentieth century,plant regeneration has been a major focus of study.Regeneration-mediated organogenesis and genetic transformation are important topics in both basic research and modern agriculture.Recent studies in the model plant Arabidopsis thaliana and other species have expanded our understanding of the molecular regulation of plant regeneration.The hierarchy of transcriptional regulation driven by phytohormone signaling during regeneration is associated with changes in chromatin dynamics and DNA methylation.Here,we summarize how various aspects of epigenetic regulation,including histone modifications and variants,chromatin accessibility dynamics,DNA methylation,and microRNAs,modulate plant regeneration.As the mechanisms of epigenetic regulation are conserved in many plants,research in this field has potential applications in boosting crop breeding,especially if coupled with emerging single-cell omics technologies.展开更多
Anatomical and chemical characteristics of stems affect lodging in wheat(Triticum aestivum L.) cultivars. Traits associated with lodging resistance, such as plant height, stem strength, culm wall thickness, pith diame...Anatomical and chemical characteristics of stems affect lodging in wheat(Triticum aestivum L.) cultivars. Traits associated with lodging resistance, such as plant height, stem strength, culm wall thickness, pith diameter, and stem diameter, were extensively investigated in earlier studies. However, the solid stem trait was rarely considered. In this study, we measured a range of anatomical and chemical characteristics on solid and hollow stemmed wheat cultivars. Significant correlations were detected between resistance to lodging and several anatomical features, including width of mechanical tissue, weight of low internodes, and width of stem walls. Morphological features that gave the best indication of improved lodging resistance were increased stem width, width of mechanical tissue layer, and stem density. Multiple linear regression analysis showed that 99% of the variation in lodging resistance could be explained by the width of the mechanical tissue layer, suggesting that solid stemmed wheat has several anatomical features for increasing resistance to lodging. In addition, microsatellite markers GWM247 and GWM340 were linked to a single solid stem QTL on chromosome 3BL in a population derived from the cross Xinongshixin(solid stem)/Line 3159(hollow stem). These markers should be valuable in breeding wheat for solid stem.展开更多
基金supported by the Ministry of Science and Technology of China (2017YFD0101000)Science and Technology Service Network Program (STS Program) of Chinese Academy of Sciences (KFJ-STS-ZDTP-024)National Natural Science Foundation of China (31371611)
文摘Grain yield in cereal crops is a complex trait controlled by multiple genes and influenced by developmental processes and environment. Here we report the effects of alleles Rht8 and Ppd-D1 a on plant height, time to heading, and grain yield and its component traits. Association analysis and quantitative trait locus mapping using phenotypic data from 15 environments led to the following conclusions. First, both Rht8 and Ppd-D1 a reduce plant height. However, Ppd-D1 a but not Rht8 causes earlier heading.Second, both Rht8 and Ppd-D1 a promote grain yield and affect component traits. Their combined effects are substantially larger than those conferred by either allele alone.Third, promotion of grain yield by Rht8 and Ppd-D1 a is through increasing fertile spikelet number. We speculate that Rht8 and Ppd-D1 a act independently and additively in control of plant height, grain yield and yield component. Combination of the two alleles is desirable for adjusting plant height and enhancing grain yield and abiotic stress tolerance.
基金jointly supported by the National Natural Science Foundation of China(32272056,U22A6009,31671673,and 31871612)Hebei Natural Science Foundation(C2021205013,C2022204202)+1 种基金Talents Program of Hebei Agricultural University in China(YJ2021016)China Agriculture Research System of MOF and MARA(CARS-03)。
文摘Thousand-kernel weight(TKW)is a measure of grain weight,a target of wheat breeding.The object of this study was to fine-map a stable quantitative trait loci(QTL)for TKW and identify its candidate gene in a recombinant inbred line(RIL)population derived from the cross of Kenong 9204(KN9204)and Jing411(J411).On a high-density genetic linkage map,24,26 and 25 QTL were associated with TKW,kernel length(KL),and kernel width(KW),respectively.A major and stable QTL,QTkw-2D,was mapped to an8.3 cM interval on chromosome arm 2DL.By saturation of polymorphic markers in its target region,QTkw-2D was confined to a 9.13 Mb physical interval using a secondary mapping population derived from a residually heterozygous line(F6:7).This interval was further narrowed to 2.52 Mb using QTkw-2D near-isogenic lines(NILs).NILs~(KN9204)had higher fresh and dry weights than NILsJ411at various grain-filling stages.The TKW and KW of NILs~(KN9204)were much higher than those of NILsJ411in field trials.By comparison of both DNA sequence and expression between KN9204 and J411,TraesCS2D02G460300.1(TraesKN2D01HG49350)was assigned as a candidate gene for QTkw-2D.This was confirmed by RNA sequencing(RNA-seq)of QTkw-2D NILs.These results provide the basis of map-based cloning of QTkw-2D,and DNA markers linked to the candidate gene may be used in marker-assisted selection.
基金financially supported by the National Key Research and Development Program of China(2016YFD0102001 and 2016YFD0102002)the National Natural Science Foundation of China(31771788)the Agricultural Science and Technology Innovation Program(ASTIP)of the Chinese Academy of Agricultural Sciences
文摘Thinopyrum intermedium and barley are two close relatives of wheat and carry many genes that are potentially valuable for the improvement of various wheat traits. In this study we created wheat double substitution lines by hybridizing different wheat–Th. intermedium and wheat–barley disomic alien substitution lines, with the aim of using genes in Th. intermedium and barley for wheat breeding and investigating the genetic behavior of alien chromosomes and their wheat homoeologs. As expected, we obtained two types of wheat double substitution lines,2D2Ai#2(2B)2H( A) and 2A2 Ai#2(2B)2H(2D), in which different group 2 wheat chromosomes were replaced by barley chromosome 2 H and Th. intermedium chromosome 2Ai#2. The new materials were characterized using molecular markers, genomic in situ hybridization(GISH), and fluorescent in situ hybridization(FISH). GISH and FISH experiments revealed that the double substitution lines harbor 42 chromosomes including 38 wheat chromosomes, a pair of barley chromosomes, and a pair of Th. intermedium chromosomes. Analysis using specific DNA markers showed that two pairs of wheat homoeologous group 2 chromosomes in the new lines were substituted by a pair of 2H and a pair of 2Ai#2 chromosomes. Chromosome 2H showed a higher transmission rate than 2Ai#2, and both chromosomes were preferentially transmitted between generations via female gametes. Evaluation of botanic and agronomic traits demonstrated that,compared with their parents, the new lines showed similar growth habits and plant type but differences in plant height, flowering date, and self-fertility. Cytological observations using different probes suggested that the double substitution lines showed nearly normal genetic behavior before and during meiosis. The novel substitution lines can potentially be used in wheat meiosis research and breeding programs.
基金This work was supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA24010104-2).
文摘Some haplotypes of the sucrose synthase gene TaSus1 are associated with thousand-grain weight(TGW)in wheat(Triticum aestivum L.).However,no mutations have been identified within the gene to test this association.The effects of TaSus1 on grain number per spike(GNS)also are largely unknown.Our previous genome-wide association study identified TaSus-A1 as a candidate gene controlling fertile spikelet number per spike(FSN).In the present study,we generated two independent mutants for the three TaSus1 homoeologs by CRISPR/Cas9-mediated genome editing.The triple mutants displayed lower FSN,GNS,grain number per spikelet(GNST),and TGW than wild-type plants.In 306 hexaploid wheat accessions,two single-nucleotide polymorphisms in TaSus-A1 contributed differently to GNS.Introgression of the two alleles into a wheat genetic background confirmed their effects.The alleles differed in geographical distribution among the accessions.
基金supported by grants from the Ministry of Science and Technology of China(Grant No.2004AA222110)the National Natural Science Foundation of China(Grant No.30225029).
文摘AtbHLH29 of Arabidopsis, encoding a bHLH protein, reveals a high similarity to the tomato FER which is proposed as a transcriptional regulator involved in controlling the iron deficiency responses and the iron uptake in tomato. For identification of its biological functions, AtbHLH29 was introduced into the genome of the tomato FER mutant T3238fer mediated by Agrobacterium tumefaciencs. Transgenic plants were regenerated and the stable integration of AtbHLH29 into their genomes was confirmed by Southern hybridization. Molecular analysis demonstrated that expression of the exogenous AtbHLH29 of Arabidopsis in roots of the FER mutant T3238fer enabled to complement the defect functions of FER. The transgenic plants regained the ability to activate the whole iron deficiency responses and showed normal growth as the wild type under iron-limiting stress. Our transformation data demonstrate that AtbHLH29 is a functional ortholog of the tomato FER and can completely replace FER in controlling the effective iron acquisition in tomato. Except of iron, FER protein was directly or indirectly involved in manganese homeostasis due to that loss functions of FER in T3238fer resulted in strong reduction of Mn content in leaves and the defect function on Mn accumulation in leaves was complemented by expression of AtbHLH29 in the transgenic plants. Identification of the similar biological functions of FER and AtbHLH29, which isolated from two systematically wide-diverged “strategy I” plants, suggests that FER might be a universal gene presented in all strategy I plants in controlling effective iron acquisition system in roots.
基金supported by the Chinese Academy of Sciences (QYZDJ-SSW-SMC001)the National Key Research and Development Program of China (2016YFD0101004)
文摘Common wheat is an important and widely cultivated food crop throughout the world.Much progress has been made in regard to wheat genome sequencing in the last decade.Starting from the sequencing of single chromosomes/chromosome arms whole genome sequences of common wheat and its diploid and tetraploid ancestors have been decoded along with the development of sequencing and assembling technologies. In this review, we give a brief summary on international progress in wheat genome sequencing, and mainly focus on reviewing the effort and contributions made by Chinese scientists.
基金financially supported by the National Key Research and Development Program of China (2016YFD0101802)
文摘Stripe rust(yellow rust), caused by Puccinia striiformis f. sp. tritici(PST),is one of the most devastating fungal diseases in common wheat(Triticum aestivum L.) in China and worldwide. Resistance breeding is the most effective strategy to control diseases in crop plants. Chinese wheat lines Mengmai 58 and Huaiyang 1 are highly resistant to PST race CYR34(V26) at the adult plant stage. To genetically map the underlying resistance genes we developed segregating populations by crossing Mengmai 58 and Huaiyang 1 with the susceptible cultivar Nongda 399. The stripe rust resistances in Mengmai 58 and Huaiyang 1 were both controlled by single dominant genes, provisionally designated YrMM58 and YrHY1, respectively. Bulked segregant RNA-Seq(BSR-Seq) analysis showed that YrMM58 and YrHY1 were located in the same distal ~16 Mb region on chromosome 2 AS.Comparative genomics analysis with the physical map of Aegilops tauschii proved useful for developing additional markers to saturate the genetic linkage map. YrMM58 and YrHY1 were mapped to the distal end of chromosome arm 2 AS, with the closest marker WGGB148 being 7.7 cM and 3.8 cM from the resistance gene, which was considered to be Yr17. These markers can be used in marker-assisted selection.
基金the Ministry of Science and Technology of China (2016YFD0100500)Chinese Academy of Sciences (XDA08020302, 2017PB0044)
文摘Wheat is the most widely cultivated staple food crop, and multiple types of food derivatives are processed and consumed globally. Wheat grain quality(WGQ) is central to food processing and nutritional value, and is a decisive factor for consumer acceptance and commercial value of wheat cultivars. Hence, improvement in WGQ traits is top priority for both conventional and molecular wheat breeding. In this review we will focus on two important WGQ traits, grain milling and end-use, and will summarize recent progress in China. Chinese scientists have invested substantial effort in molecular genetic and genomic analysis of these traits and their effects on end-use properties. The insights and resources generated have contributed to the understanding and improvement of these traits. As high-quality genomics information and powerful genome engineering tools are becoming available for wheat, more fundamental breakthroughs in dissecting the molecular and genomic basis of WGQ are expected. China will strive to make further significant contributions to the study and improvement of WGQ in the genomics era.
基金funded by the National Key Research and Development Program of China (2017YFD0201701)the Special Fund for Agro-scientific Research in the Public Interest,China (201303016)the Science and Technology Project for Xingjiang Uygur Autonomous Region,China (2013911092)
文摘Powdery mildew,caused by Blumeria graminis f.sp.tritici(Bgt),is one of the most damaging diseases to wheat in the world.The cultivation of resistant varieties of wheat is essential for controlling the powdery mildew epidemic.Wheat landraces are important resources of resistance to many diseases.Mapping powdery mildew resistance genes from wheat landraces will promote the development of new varieties with disease resistance.The Chinese wheat landrace Baiyouyantiao possesses characteristic of disease resistance to powdery mildew.To identify the resistance gene in this landrace,Baiyouyantiao was crossed with the susceptible cultivar Jingshuang 16 and seedlings of parents and F_1,BC_1,F_2,and F_(2:3) were tested with Bgt isolate E09.The genetic results showed that the resistance of Baiyouyantiao to E09 was controlled by a single recessive gene,tentatively designated Pm BYYT.An Illumina wheat 90K single-nucleotide polymorphism(SNP)array was applied to screen polymorphisms between F_2-resistant and F_2-susceptible DNA bulks for identifying the chromosomal location of Pm BYYT.A high percentage of polymorphic SNPs between the resistant and susceptible DNA bulks was found on chromosome 7B,indicating that Pm BYYT may be located on this chromosome.A genetic linkage map of Pm BYYT consisting of two simple sequence repeat markers and eight SNP markers was developed.The two flanking markers were SNP markers W7BL-8 and W7BL-15,with genetic distances of 3 and 2.9 c M,respectively.The results of this study demonstrated the rapid characterization of a wheat disease resistance gene and SNP marker development using the 90K SNP assay.The flanking markers of gene Pm BYYT will benefit marker-assisted selection(MAS)and map-based cloning in breeding wheat cultivars with powdery mildew resistance.
基金jointly supported by Natural Science Foundation of Hebei Province(C2018207020)National Natural Science Foundation of China(31771784)+1 种基金Hebei Provincial Science and Technology Research and Development Project(16226320D)China Agriculture Research System(CARS-03-01B)。
文摘The TaGS3 homoeologous genes(homoeologs)located on chromosomes 7 A,4 A,and7 D in hexaploid wheat were cloned.Relative expression analysis of the three Ta GS3 homoeologs revealed that the expression levels of TaGS3-4 A and TaGS3-7 D in developing grains were higher than that of TaGS3-7 A.Genetic evidence showed that Ta GS3 was a negative regulator of grain weight and grain size.Fifteen polymorphic sites and five haplotypes were detected in TaGS3-4 A.Two molecular markers were developed to distinguish the five haplotypes.Association analysis using 260 accessions from Chinese wheat mini-core collection(MCC)indicated that TaGS3-4 A affected thousand grain weight(TGW)and grain length(GL).HAP-4 A-1 and HAP-4 A-2 were favorable haplotypes that increased TGW and GL and had undergone strong selection during domestication of wheat.In addition,interaction of the TaGS3-4 A and TaGS3-7 D homoeologs had significant additive effects on the grain traits.Hap-4 A-1/Hap-7 D-2 was the best haplotype combination in increasing TGW and GL.The frequencies and geographic distributions of favorable TaGS3 haplotypes among 1388 wheat accessions from worldwide sources provided clues for selection of yield-related traits.Our findings demonstrated that TaGS3-4 A had significant effects on TGW and GL.Marker-assisted selection of HAP-4 A-1/2 combined with HAP-7 D-2 has potential to increase wheat yields.
基金supported by grants from the National Basic Research Program of China(2013CBA01401)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA08020108)the Platform Construction Programs of Key Laboratory and Engineering Technology Research Center,Department of Science and Technology of Hainan Province,China(ZDZX2013023)
文摘Grain size is one of the most important agronomic components of grain yield. Grain length, width and thickness are controlled by multiple quantitative trait loci(QTLs). To understand genetic basis of large grain shape and explore the beneficial alleles for grain size improvement, we perform QTL analysis using an F2 population derived from a cross between the japonica variety Beilu 129(BL129, wide and thick grain) and the elite indica variety Huazhan(HZ, narrow and long grain). A total number of eight major QTLs are detected on three different chromosomes. QTLs for grain width(q GW), grain thickness(q GT), brown grain width(q BGW), and brown grain thickness(q BGT) explained 7 7.67, 36.24, 89.63, and 39.41% of total phenotypic variation, respectively. The large grain rice variety BL129 possesses the beneficial alleles of GW2 and q SW5/GW5, which have been known to control grain width and weight, indicating that the accumulation of the beneficial alleles causes large grain shape in BL129. Further results reveal that the rare gw2 allele from BL129 increases grain width, thickness and weight of the elite indica variety Huazhan, which is used as a parental line in hybrid rice breeding. Thus, our findings will help breeders to carry out molecular design breeding on rice grain size and shape.
基金supported by National Key Research and Development Program of China(2018YFD1000703,2018YFD1000700)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB11020400)+3 种基金National Program on Research and Development of Transgenic Plants(2016ZX08009-003-001)Startup Fund for Advanced Talents of Lushan Botanical GardenChinese Academy of Science(2020ZWZX03 and 2020ZWZX05)the“Double Hundred and Double Thousand”Talent Project of Jiujiang City(jjsbsq2020026)。
文摘Plants use a sophisticated immune system to perceive pathogen infection and activate immune responses in a tightly controlled manner.In barley,Hv WRKY2 acts as a repressor in barley disease resistance to the powdery mildew fungus,Blumeria graminis f.sp.hordei(Bgh).However,the molecular features of Hv WRKY2 in its DNA-binding and repressor functions,as well as its target genes,are uncharacterized.We show that the W-box binding of Hv WRKY2 requires an intact WRKY domain and an upstream sequence of~75 amino acids,and the Hv WRKY2 W-box binding activity is linked to its repressor function in disease resistance.Chromatin immunoprecipitation(ChIP)-seq analysis identified HvCEBiP,a putative chitin receptor gene,as a target gene of Hv WRKY2 in overexpressing transgenic barley plants.ChIP-qPCR and Electrophoretic Mobility Shift Assay(EMSA)verified the direct binding of Hv WRKY2 to a W-boxcontaining sequence in the HvCEBiP promoter.Hv CEBiP positively regulates resistance against Bgh in barley.Our findings suggest that Hv WRKY2 represses barley basal immunity by directly targeting pathogen-associated molecular pattern(PAMP)recognition receptor genes,suggesting that Hv CEBiP and likely chitin signaling function in barley PAMP-triggered immune responses to Bgh infection.
基金supported by the National Key Research and Development Program of China(2016YFD0100302)the Science and Technology Service Network Initiative of Chinese Academy of Sciences(KFJ-STS-ZDTP-024)。
文摘Reduced plant height is one of the most important traits related to lodging resistance and crop yield. The use of reduced height genes has been one of the main features in breeding modern high-yielding wheat varieties with less lodging. A spontaneous dwarf mutant DD399 was identified in a high yielding, gibberellic acid(GA)-insensitive, lodging-resistant variety Nongda 399(ND399). Significant differences in upper internode lengths between mutant DD399 and wild type ND399 were caused by reduced cell elongation. The plant height of ND399 × DD399 F_(1) hybrids was intermediate between the parents, indicating incomplete dominance or a dose–response effect of a reduced height gene. Plant height showed continuous distribution in the F_(2) population, and segregation distortion was observed among the 2292 F_(2:3) progenies. The reduced height mutation was characterized by Illumina 90 K iSelect SNP genotyping and bulked segregant RNA-Seq(BSR-Seq) analysis of the segregating population. A concentrated cluster of polymorphic SNPs associated with the reduced height phenotype was detected in the distal region of chromosome arm 2 BL. Co-segregation of reduced height phenotype with the clustered markers revealed a 36 Mb terminal deletion of chromosome 2 BL in mutant DD399.
基金supported by the National Key Research and Development Program of China(2016YFD0101802)Exploring Candidate Genes of heat root length by integrative genomics(PCCE-KF-2018-02)。
文摘Awns play an important role in seed dispersal and photosynthesis of spikes.Three major awn inhibitors(Hd,B1,and B2)are reported in wheat.However,the molecular mechanism underlying awnlessness remained unknown until recently.In this study,we identified two F8 recombinant inbred lines(RILs)that were segregating for awn length.In order to identify the causal gene for awn length in the heterozygous inbred families(HIFs),SNPs were called from RNA sequencing(RNA-Seq)data for HIF-derived progenies with long and short awns.SNPs between long and short awn plants were evenly distributed on chromosomes(chr)other than chromosome 5 A.SNPs on chr 5 A were clustered in a region distal 688 Mb on the long arm,where inhibitor B1 was located.This suggested that B1 was the causal segregating locus.We precisely mapped B1 to^1 Mb region using two HIF-derived families.Considering that the lines segregated for long,intermediate and short awn phenotypes we speculated that B1 should have a dosage effect on awn length.Two differentially expressed genes(DEGs)located in the candidate region were regarded as candidate genes for B1,because the molecular expression pattern was consistent with the phenotype.HIFs with long and short awns showed no difference on grain yield and other agronomic traits.
基金supported by the grants from the Shandong Major Basic Research Project of Natural Science Foundation,China(ZR2019ZD16)the Shandong Provincial Key Research and Development Program,China(2019GNC106126 and 2021LZGC009)+3 种基金the Natural Science Foundation of Hebei Province,China(C2021205013)the Hebei Scientific and Technological Innovation Team of Modern Wheat Seed Industry,China(21326318D)the National Natural Science Foundation of China(31871612,31901535,and 32101726)the China Agriculture Research System of MOF and MARA(CARS-03).
文摘The foundation parents play key roles in the genetic improvement of both yield potential and end-use quality in wheat.Characterizing the genetic basis that underlies certain beneficial traits in the foundation parents will provide theoretical reference for molecular breeding by a design approach.‘Kenong 9204’(KN9204)is a candidate foundation parent characterized by ideotype,high yield potential,and particularly high nitrogen fertilizer utilization.To better understand the genetic basis of its high yield potential,high throughput whole-genome re-sequencing(10×)was performed on KN9204,its parental lines and its derivatives.A high-resolution genetic composition map of KN9204 was constructed,which showed the parental origin of the favorable genomic segments based on the identification of excellent yield-related quantitative trait loci(QTL)from a bi-parental mapping population.Xiaoyan 693(XY693),a wheat–Thinopyrum ponticum partial amphidiploid,contributed a great deal to the high yield potential of KN9204,and three major stable QTLs from XY693 were fine mapped.The transmissibility of key genomic segments from KN9204 to its derivatives were delineated,indicating that haplotype blocks containing beneficial gene combinations were conserved along with directional selection by breeders.Evidence for selection sweeps in the breeding programs was identified.This study provides a theoretical reference for the breeding of high-yield wheat varieties by a molecular design approach.
基金supported by the National Natural Science Foundation of China(31921005)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24010204)+1 种基金the National Key Research and Development Program of China(2021YFD1201500)the Major Basic Research Program of Shandong Natural Science Foundation of China(ZR2019ZD15).
文摘The spike architecture of wheat plays a crucial role in determining grain number,making it a key trait for optimization in wheat breeding programs.In this study,we used a multi-omic approach to analyze the transcriptome and epigenome profiles of the young spike at eight developmental stages,revealing co-ordinated changes in chromatin accessibility and H3K27me3 abundance during the flowering transition.We constructed a core transcriptional regulatory network(TRN)that drives wheat spike formation and experimentally validated a multi-layer regulatorymodule involving TaSPL15,TaAGLG1,and TaFUL2.By integrating the TRN with genome-wide association studies,we identified 227 transcription factors,including 42 with known functions and 185 with unknown functions.Further investigation of 61 novel transcription factors using multiple homozygous mutant lines revealed 36 transcription factors that regulate spike architecture or flowering time,such as TaMYC2-A1,TaMYB30-A1,and TaWRKY37-A1.Of particular interest,TaMYB30-A1,downstream of and repressed by WFzP,was found to regulate fertile spikelet number.Notably,the excellent haplotype of TaMYB30-A1,which contains a C allele at the WFzP binding site,was enriched during wheat breeding improvement in China,leading to improved agronomic traits.Finally,we constructed a free and open access Wheat Spike Multi-Omic Database(http://39.98.48.156:8800/#/).Our study identifies novel and high-confidence regulators and offers an effective strategy for dissecting the genetic basis of wheat spike development,with practical value forwheat breeding.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA24010204)the National Key Research and Development to Program of China(2021YFD1201500)the National Natural Sciences Foundation of China(31970529)to J.X.
文摘Ever since the concept of"plant cell totipotency"was first proposed in the early twentieth century,plant regeneration has been a major focus of study.Regeneration-mediated organogenesis and genetic transformation are important topics in both basic research and modern agriculture.Recent studies in the model plant Arabidopsis thaliana and other species have expanded our understanding of the molecular regulation of plant regeneration.The hierarchy of transcriptional regulation driven by phytohormone signaling during regeneration is associated with changes in chromatin dynamics and DNA methylation.Here,we summarize how various aspects of epigenetic regulation,including histone modifications and variants,chromatin accessibility dynamics,DNA methylation,and microRNAs,modulate plant regeneration.As the mechanisms of epigenetic regulation are conserved in many plants,research in this field has potential applications in boosting crop breeding,especially if coupled with emerging single-cell omics technologies.
基金supported by the National Basic Research Program of China (2011CB100302)the Knowledge Innovation Program of CAS (KSCX2-EW-N-02)
文摘Anatomical and chemical characteristics of stems affect lodging in wheat(Triticum aestivum L.) cultivars. Traits associated with lodging resistance, such as plant height, stem strength, culm wall thickness, pith diameter, and stem diameter, were extensively investigated in earlier studies. However, the solid stem trait was rarely considered. In this study, we measured a range of anatomical and chemical characteristics on solid and hollow stemmed wheat cultivars. Significant correlations were detected between resistance to lodging and several anatomical features, including width of mechanical tissue, weight of low internodes, and width of stem walls. Morphological features that gave the best indication of improved lodging resistance were increased stem width, width of mechanical tissue layer, and stem density. Multiple linear regression analysis showed that 99% of the variation in lodging resistance could be explained by the width of the mechanical tissue layer, suggesting that solid stemmed wheat has several anatomical features for increasing resistance to lodging. In addition, microsatellite markers GWM247 and GWM340 were linked to a single solid stem QTL on chromosome 3BL in a population derived from the cross Xinongshixin(solid stem)/Line 3159(hollow stem). These markers should be valuable in breeding wheat for solid stem.
基金The authors thank ProfMary Lou Guerinot (Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire) for providing IRT1 peptide antibody and for the critical reading of the manuscript. We are also grateful to Drs Zhentao Lin and Yongfu Fu (Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing) for providing the BiFC assay system and technical supporting. This work was supported by the National Natural Science Foundation of China (Grant nos, 30530460 and 30521001) and the Ministry of Science and Technology of China (Grant nos, 2005cb20904 and 2006AA 10A 105) and Chinese Academy of Sciences (Grant no. KSCX2-YW-N- 001) as well as by the Harvest Plus-China Program.