Aegilops variabilis(S^(v)S^(v)U^(v)U^(v))is a source of resistance to wheat stripe rust.The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai(KL)can induce homoeologous wheat-alien chromosome pairing and r...Aegilops variabilis(S^(v)S^(v)U^(v)U^(v))is a source of resistance to wheat stripe rust.The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai(KL)can induce homoeologous wheat-alien chromosome pairing and recombination.In this study,we confirmed that the whole 2S^(v)chromosome introgressed into wheat from Ae.variabilis accession AS116 conferred all-stage stripe rust resistance.The underlying gene(s),named YrAev,was mapped to the long arm 2S^(v)L using an F_(2)population.Two 2S^(v)-2B recombinants,derived from a cross of the 2S^(v)(2B)chromosome substitution line and KL,were confirmed to harbor the resistance locus.The physical region containing YrAev,determined from RNA-seq data,was 844.6-852.1 Mb on the chromosome arm 2S^(l)of the Ae.longissima(S^(v)genome donor species of Ae.variabilis)accession TL05 assembly v1.0.Differential gene expression analysis of post-inoculation with the Pst race has indicated two disease-resistance-related genes(annotated as mixed lineage kinase domain-like protein and nucleotide-binding leucine-rich repeat like protein,respectively)as promising candidates for YrAev.This study demonstrates the utility of the phKL gene system in alien gene localization and transfer.The resistant translocation line harboring YrAev can be exploited by wheat breeders as a novel source of resistance to stripe rust.展开更多
The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characterist...The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characteristics of homoeologous pairing and recombination induced by phKL.In KL haploids,the level of homoeologous pairing was elevated relative to Ph1 Chinese Spring(CS)haploids.There was a clear preference for A–D pairing and less frequent for A–B and B–D,reflecting the higher levels of affinity between genomes A and D in wheat.The characteristics of pairing were affected by temperature and magnesium ion supplementation.The suitability of phKL for chromosome engineering was tested on three pairs of homoeologues:2Sv-2B,2Sv-2D,and 2RL-2BL.The recombination rates were 1.68%,0.17%,and 0%,respectively.The phKL locus in KL induced a moderate level of homoeologous chromosome pairing and recombination when the Ph1 locus of wheat was present,both in wheat haploids and hexaploids.The Ph1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree,permitting homoeologous crossing over but only between closely related chromosomes;there was no crossing over between more differentiated chromosomes.Therefore,the phKL system(QPh.sicau-3A)can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by the ph1b mutation.展开更多
Dear Editor,The 1RS-1BL translocation chromosome,carrying the stripe rust resistance gene Yr9,has shaped global wheat breeding for half a century.The 1RS-1BL translocation chromosome,derived from the exchange between ...Dear Editor,The 1RS-1BL translocation chromosome,carrying the stripe rust resistance gene Yr9,has shaped global wheat breeding for half a century.The 1RS-1BL translocation chromosome,derived from the exchange between rye and wheat chromosomes,not only introduced Yr9into wheat but also incorporated Sr31,Lr26,and Pm8,thereby forming a robust arsenal of disease-resistance genes(Mago et al.,2005).In China,the 1RS-1BL cultivars like "Aimengniu", "Lovrin 10".展开更多
Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat...Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat,remains elusive.Here,we systematically analyzed seven non-B-form DNA motif profiles(A-phased DNA repeat,direct repeat,G-quadruplex,inverted repeat,mirror repeat,short tandem repeat,and Z-DNA)in hexaploid wheat.We found that three of these non-B-form DNA motifs were enriched at centromeric regions,especially at the CENH3-binding sites,suggesting that non-B-form DNA may create a favorable loading environment for the CENH3 nucleosome.To investigate the dynamics of centromeric non-B form DNA during the alloploidization process,we analyzed DNA secondary structure using CENH3 ChIP-seq data from newly formed allotetraploid wheat and its two diploid ancestors.We found that newly formed allotetraploid wheat formed more non-B-form DNA in centromeric regions compared with their parents,suggesting that non-B-form DNA is related to the localization of the centromeric regions in newly formed wheat.Furthermore,non-B-form DNA enriched in the centromeric regions was found to preferentially form on young LTR retrotransposons,explaining CENH3's tendency to bind to younger LTR.Collectively,our study describes the landscape of non-B-form DNA in the wheat genome,and sheds light on its potential role in the evolution of polyploid centromeres.展开更多
基金supported by the National Natural Science Foundation of China(32172020,31971884)the National Key Research and Development Program of China(2024YFD1201202,2024YFD1200402)+4 种基金the Sichuan Science and Technology Program(2022ZDZX0014,2023YFN0085)the Qinghai Provincial Key Laboratory of Crop Molecular Breeding(2023-1-1)the State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China(SKLKF202409)the Alliance of National and International Science Organizations for the Belt and Road Regions(ANSO-CR-KP-202205)the International Partnership Program of Chinese Academy of Sciences(077GJHZ2023028GC)。
文摘Aegilops variabilis(S^(v)S^(v)U^(v)U^(v))is a source of resistance to wheat stripe rust.The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai(KL)can induce homoeologous wheat-alien chromosome pairing and recombination.In this study,we confirmed that the whole 2S^(v)chromosome introgressed into wheat from Ae.variabilis accession AS116 conferred all-stage stripe rust resistance.The underlying gene(s),named YrAev,was mapped to the long arm 2S^(v)L using an F_(2)population.Two 2S^(v)-2B recombinants,derived from a cross of the 2S^(v)(2B)chromosome substitution line and KL,were confirmed to harbor the resistance locus.The physical region containing YrAev,determined from RNA-seq data,was 844.6-852.1 Mb on the chromosome arm 2S^(l)of the Ae.longissima(S^(v)genome donor species of Ae.variabilis)accession TL05 assembly v1.0.Differential gene expression analysis of post-inoculation with the Pst race has indicated two disease-resistance-related genes(annotated as mixed lineage kinase domain-like protein and nucleotide-binding leucine-rich repeat like protein,respectively)as promising candidates for YrAev.This study demonstrates the utility of the phKL gene system in alien gene localization and transfer.The resistant translocation line harboring YrAev can be exploited by wheat breeders as a novel source of resistance to stripe rust.
基金supported by the National Natural Science Foundation of China(31971884,31601300,32172020)USDANIFA(#CA-R-BPS-5411-H)to AJL+1 种基金Natural Science Foundation of Sichuan Province(2022NSFSC1696,2019YJ0415)the National Key Research and Development Program of China(2016YFD0102000)。
文摘The Chinese wheat landrace Kaixianluohanmai(KL)expresses the ph-like phenotype.A major QTL,QPh.sicau-3A(syn.phKL),responsible for this effect has been mapped to chromosome arm 3AL.This study presents some characteristics of homoeologous pairing and recombination induced by phKL.In KL haploids,the level of homoeologous pairing was elevated relative to Ph1 Chinese Spring(CS)haploids.There was a clear preference for A–D pairing and less frequent for A–B and B–D,reflecting the higher levels of affinity between genomes A and D in wheat.The characteristics of pairing were affected by temperature and magnesium ion supplementation.The suitability of phKL for chromosome engineering was tested on three pairs of homoeologues:2Sv-2B,2Sv-2D,and 2RL-2BL.The recombination rates were 1.68%,0.17%,and 0%,respectively.The phKL locus in KL induced a moderate level of homoeologous chromosome pairing and recombination when the Ph1 locus of wheat was present,both in wheat haploids and hexaploids.The Ph1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree,permitting homoeologous crossing over but only between closely related chromosomes;there was no crossing over between more differentiated chromosomes.Therefore,the phKL system(QPh.sicau-3A)can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by the ph1b mutation.
基金supported by the National Natural Science Foundation of China (NSFC31991212)the National Key Research and Development Program of China (2022YFF1003303)。
文摘Dear Editor,The 1RS-1BL translocation chromosome,carrying the stripe rust resistance gene Yr9,has shaped global wheat breeding for half a century.The 1RS-1BL translocation chromosome,derived from the exchange between rye and wheat chromosomes,not only introduced Yr9into wheat but also incorporated Sr31,Lr26,and Pm8,thereby forming a robust arsenal of disease-resistance genes(Mago et al.,2005).In China,the 1RS-1BL cultivars like "Aimengniu", "Lovrin 10".
基金supported by the National Natural Science Foundation of China(31991212)the National Key Research and Development Program of China(2022YFF1003303)。
文摘Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat,remains elusive.Here,we systematically analyzed seven non-B-form DNA motif profiles(A-phased DNA repeat,direct repeat,G-quadruplex,inverted repeat,mirror repeat,short tandem repeat,and Z-DNA)in hexaploid wheat.We found that three of these non-B-form DNA motifs were enriched at centromeric regions,especially at the CENH3-binding sites,suggesting that non-B-form DNA may create a favorable loading environment for the CENH3 nucleosome.To investigate the dynamics of centromeric non-B form DNA during the alloploidization process,we analyzed DNA secondary structure using CENH3 ChIP-seq data from newly formed allotetraploid wheat and its two diploid ancestors.We found that newly formed allotetraploid wheat formed more non-B-form DNA in centromeric regions compared with their parents,suggesting that non-B-form DNA is related to the localization of the centromeric regions in newly formed wheat.Furthermore,non-B-form DNA enriched in the centromeric regions was found to preferentially form on young LTR retrotransposons,explaining CENH3's tendency to bind to younger LTR.Collectively,our study describes the landscape of non-B-form DNA in the wheat genome,and sheds light on its potential role in the evolution of polyploid centromeres.
