Accurate genomic information is essential for advancing genetic breeding research in specific rice varieties.This study presented a gapless genome assembly of the indica rice cultivar Zhonghui 8015(ZH8015)using Pac Bi...Accurate genomic information is essential for advancing genetic breeding research in specific rice varieties.This study presented a gapless genome assembly of the indica rice cultivar Zhonghui 8015(ZH8015)using Pac Bio HiFi,Hi-C,and ONT(Oxford Nanopore Technologies)ultra-long sequencing technologies,annotating 43037 gene structures.Subsequently,utilizing this genome along with transcriptomic and metabolomic techniques,we explored ZH8015's response to brown planthopper(BPH)infestation.Continuous transcriptomic sampling indicated significant changes in gene expression levels around 48 h after BPH feeding.Enrichment analysis revealed particularly significant alterations in genes related to reactive oxygen species scavenging and cell wall formation.Metabolomic results demonstrated marked increases in levels of several monosaccharides,which are components of the cell wall and dramatic changes in flavonoid contents.Omics association analysis identified differentially expressed genes associated with key metabolites,shedding light on ZH8015's response to BPH infestation.In summary,this study constructed a reliable genome sequence resource for ZH8015,and the preliminary multi-omics results will guide future insect-resistant breeding research.展开更多
Superior inbred lines are central to maize breeding as sources of natural variation.Although many elite lines have been sequenced,less sequencing attention has been paid to newly developed lines.We constructed a genom...Superior inbred lines are central to maize breeding as sources of natural variation.Although many elite lines have been sequenced,less sequencing attention has been paid to newly developed lines.We constructed a genome assembly of the elite inbred line KA105,which has recently been developed by an arti-ficial breeding population named Shaan A and has shown desirable characteristics for breeding.Its pedigree showed genetic divergence from B73 and other lines in its pedigree.Comparison with the B73 reference genome revealed extensive structural variation,58 presence/absence variation(PAV)genes,and 1023 expanded gene families,some of which may be associated with disease resistance.A network-based integrative analysis of stress-induced transcriptomes identified 13 KA105-specific PAV genes,of which eight were induced by at least one kind of stress,participating in gene modules responding to stress such as drought and southern leaf blight disease.More than 200,000 gene pairs were differentially correlated between KA105 and B73 during kernel development.The KA105 reference genome and transcriptome atlas are a resource for further germplasm improvement and surveys of maize genomic variation and gene function.展开更多
The current assembled maize genomes cannot represent the broad genetic diversity of maize germplasms.Acquiring more genome sequences is critical for constructing a pan-genome and elucidating the linkage between genoty...The current assembled maize genomes cannot represent the broad genetic diversity of maize germplasms.Acquiring more genome sequences is critical for constructing a pan-genome and elucidating the linkage between genotype and phenotype in maize.Here we describe the genome sequence and annotation of A188,a maize inbred line with high phenotypic variation relative to other lines,acquired by single-molecule sequencing and optical genome mapping.We assembled a 2210-Mb genome with a scaffold N50 size of 11.61 million bases(Mb),compared to 9.73 Mb for B73 and 10.2 Mb for Mo17.Based on the B73_Ref Gen_V4 genome,295 scaffolds(2084.35 Mb,94.30%of the final genome assembly)were anchored and oriented on ten chromosomes.Comparative analysis revealed that~30%of the predicted A188 genes showed large structural divergence from B73,Mo17,and W22 genomes,which causes high protein divergence and may lead to phenotypic variation among the four inbred lines.As a line with high embryonic callus(EC)induction capacity,A188 provides a convenient tool for elucidating the molecular mechanism underlying the formation of EC in maize.Combining our new A188 genome with previously reported QTL and RNA sequencing data revealed eight genes with large structural variation and two differentially expressed genes playing potential roles in maize EC induction.展开更多
Background:Arundo donax L.has great potential as an energy crop due to its high biomass yield and broad adaptability,while lack of a reference genome is a hindrance to genetic improvement efforts for this species.Meth...Background:Arundo donax L.has great potential as an energy crop due to its high biomass yield and broad adaptability,while lack of a reference genome is a hindrance to genetic improvement efforts for this species.Methods:Genome assembly of A.donax was conducted by utilizing PacBio SMRT sequencing and high-throughput chromosome conformation capture technology,with further analysis exploring the plant's ploidy,whole-genome duplication event,and evolutionary history through comparative genomics.Results:The genome assembly of A.donax consists of 1.30 Gb with a contig N50 size of 33.15 Mb.A total of 74403 gene models were identified,with over 90%of genes being functionally annotated.Karyotype and synteny analyses revealed that A.donax is an autoalloenneaploid(3n=9x=108)and has experienced significant gene family expansion and two whole-genome duplication events during its evolutionary history.Furthermore,utilizing the genome assembly,a variety of salinity stress-related genes were uncovered through the analysis of public RNA-seq data.Conclusions:This study presents the initial chromosome-scale genome assembly of A.donax,which will advance genetic comprehension and support the genetic enhancement of this important energy crop.展开更多
With the rapid development of sequencing technologies,especially the maturity of third-generation sequencing technologies,there has been a significant increase in the number and quality of published genome assemblies....With the rapid development of sequencing technologies,especially the maturity of third-generation sequencing technologies,there has been a significant increase in the number and quality of published genome assemblies.The emergence of these high-quality genomes has raised higher requirements for genome evaluation.Although numerous computational methods have been developed to evaluate assembly quality from various perspectives,the selective use of these evaluation methods can be arbitrary and inconvenient for fairly comparing the assembly quality.To address this issue,we have developed the Genome Assembly Evaluating Pipeline(GAEP),which provides a comprehensive assessment pipeline for evaluating genome quality from multiple perspectives,including continuity,completeness,and correctness.Additionally,GAEP includes new functions for detecting misassemblies and evaluating the assembly redundancy,which performs well in our testing.GAEP is publicly available at https://github.com/zyoptimistic/GAEP under the GPL3.0 License.With GAEP,users can quickly obtain accurate and reliable evaluation results,facilitating the comparison and selection of high-quality genome assemblies.展开更多
JUJUNCAO(Cenchrus fungigraminus;2n=4x=28)is a Cenchrus grass with the highest biomass production among cultivated plants,and it can be used for mushroom cultivation,animal feed,and biofuel production.Here,we report a ...JUJUNCAO(Cenchrus fungigraminus;2n=4x=28)is a Cenchrus grass with the highest biomass production among cultivated plants,and it can be used for mushroom cultivation,animal feed,and biofuel production.Here,we report a nearly complete genome assembly of JUJUNCAO and reveal that JUJUNCAO is an allopolyploid that originated2.7 million years ago(mya).Its genome consists of two subgenomes,and subgenome A shares high collinear synteny with pearl millet.We also investigated the genome evolution of JUJUNCAO and suggest that the ancestral karyotype of Cenchrus split into the A and B ancestral karyotypes of JUJUNCAO.Comparative transcriptome and DNA methylome analyses revealed functional divergence of homeologous gene pairs between the two subgenomes,which was a further indication of asymmetric DNA methylation.The three types of centromeric repeat in the JUJUNCAO genome(CEN137,CEN148,and CEN156)may have evolved independently within each subgenome,with some introgressions of CEN156 from the B to the A subgenome.We investigated the photosynthetic characteristics of JUJUNCAO,revealing its typical C4 Kranz anatomy and high photosynthetic efficiency.NADP-ME and PEPCK appear to cooperate in the major C4 decarboxylation reaction of JUJUNCAO,which is different from other C4 photosynthetic subtypes and may contribute to its high photosynthetic efficiency and biomass yield.Taken together,our results provide insights into the highly efficient photosynthetic mechanism of JUJUNCAO and provide a valuable reference genome for future genetic and evolutionary studies,as well as genetic improvement of Cenchrus grasses.展开更多
Plants of the Caprifoliaceae family are widely cultivated worldwide as ornamental plants owing to their numerous,sweet-smelling,beautiful flowers and fruits.Heptacodium miconioides Rehd.,a member of the family,is ende...Plants of the Caprifoliaceae family are widely cultivated worldwide as ornamental plants owing to their numerous,sweet-smelling,beautiful flowers and fruits.Heptacodium miconioides Rehd.,a member of the family,is endemic to eastern China and is cultivated as a popular ornamental plant in North America and European countries.It has a rather novel and beautiful trait of high horticultural value,that is,its sepals persist and enlarge,turning purplish red.Here,we report the chromosome-level genome assembly of H.miconioides to understand its evolution and floral characteristics.The 622.28 Mb assembled genome harbored a shared whole-genome duplication with a related species,Lonicera japonica.Comparative genomic analysis suggested that chromosome fission events following genome duplication underlie the unusual chromosome number of these two species,as well as chromosome fission of another five chromosomes in H.miconioides,giving rise to a haploid chromosome number of 14(versus 9 in L.japonica).In addition,based on transcriptome and chloroplast genome analysis of 17 representative species in the Caprifoliaceae,we assumed that large structural variations in the chromosomes of H.miconioides were not caused by hybridization.Changes in the candidate genes of the MADS-box family were detected in the H.miconioides genome,including AP1-,AP3-,and SEPexpanded,which might underlie the sepal elongation and development in this species.The current findings provided a critical resource for genome evolution studies in Caprifoliaceae and it was an example of how multi-omics data can elucidate the regulation of important ornamental traits.展开更多
High-quality rice reference genomes have accelerated the comprehensive identification of genome-wide variations and research on functional genomics and breeding.Tian-you-hua-zhan has been a leading hybrid in China ove...High-quality rice reference genomes have accelerated the comprehensive identification of genome-wide variations and research on functional genomics and breeding.Tian-you-hua-zhan has been a leading hybrid in China over the past decade.Here,de novo genome assembly strategy optimization for the rice indica lines Huazhan(HZ)and Tianfeng(TF),including sequencing platforms,assembly pipelines and sequence depth,was carried out.The PacBio and Nanopore platforms for long-read se-quencing were utilized,with the Canu,wtdbg2,SMARTdenovo,Flye,Canu-wtdbg2,Canu-SMARTdenovo and Canu-Flye assemblers.The combination of PacBio and Canu was optimal,considering the contig N50 length,contig number,assembled genome size and polishing process.The assembled contigs were scaffolded with Hi-C data,resulting in two“golden quality”rice reference genomes,and evaluated using the scaffold N50,BUSCO,and LTR assembly index.Furthermore,42,625 and 41,815 non-transposable element genes were annotated for HZ and TF,respectively.Based on our assembly of HZ and TF,as well as Zhenshan97,Minghui63,Shuhui498 and 9311,comprehensive variations were identified using Nipponbare as a reference.The de novo assembly strategy for rice we optimized and the“golden quality”rice genomes we produced for HZ and TF will benefit rice genomics and breeding research,especially with respect to uncovering the genomic basis of the elite traits of HZ and TF.展开更多
Alfalfa(Medicago sativa L.)is the most important legume forage crop worldwide with high nutritional value and yield.For a long time,the breeding of alfalfa was hampered by lacking reliable information on the autotetra...Alfalfa(Medicago sativa L.)is the most important legume forage crop worldwide with high nutritional value and yield.For a long time,the breeding of alfalfa was hampered by lacking reliable information on the autotetraploid genome and molecular markers linked to important agronomic traits.We herein reported the de novo assembly of the allele-aware chromosome-level genome of Zhongmu-4,a cultivar widely cultivated in China,and a comprehensive database of genomic variations based on resequencing of 220 germplasms.Approximate 2.74 Gb contigs(N50 of 2.06 Mb),accounting for 88.39%of the estimated genome,were assembled,and 2.56 Gb contigs were anchored to 32 pseudo-chromosomes.A total of 34,922 allelic genes were identified from the allele-aware genome.We observed the expansion of gene families,especially those related to the nitrogen metabolism,and the increase of repetitive elements including transposable elements,which probably resulted in the increase of Zhongmu-4 genome compared with Medicago truncatula.Population structure analysis revealed that the accessions from Asia and South America had relatively lower genetic diversity than those from Europe,suggesting that geography may influence alfalfa genetic divergence during local adaption.Genome-wide association studies identified 101 single nucleotide polymorphisms(SNPs)associated with 27 agronomic traits.Two candidate genes were predicted to be correlated with fall dormancy and salt response.We believe that the alleleaware chromosome-level genome sequence of Zhongmu-4 combined with the resequencing data of the diverse alfalfa germplasms will facilitate genetic research and genomics-assisted breeding in variety improvement of alfalfa.展开更多
Wild castor grows in the high-altitude tropical desert of the African Plateau,a region known for high ultraviolet radiation,strong light,and extremely dry condition.To investigate the potential genetic basis of adapta...Wild castor grows in the high-altitude tropical desert of the African Plateau,a region known for high ultraviolet radiation,strong light,and extremely dry condition.To investigate the potential genetic basis of adaptation to both highland and tropical deserts,we generated a chromosome-level genome sequence assembly of the wild castor accession WT05,with a genome size of 316 Mb,a scaffold N50 of 31.93 Mb,and a contig N50 of 8.96 Mb,respectively.Compared with cultivated castor and other Euphorbiaceae species,the wild castor exhibits positive selection and gene family expansion for genes involved in DNA repair,photosynthesis,and abiotic stress responses.Genetic variations associated with positive selection were identified in several key genes,such as LIG1,DDB2,and RECG1,involved in nucleotide excision repair.Moreover,a study of genomic diversity among wild and cultivated accessions revealed genomic regions containing selection signatures associated with the adaptation to extreme environments.The identification of the genes and alleles with selection signatures provides insights into the genetic mechanisms underlying the adaptation of wild castor to the high-altitude tropical desert and would facilitate direct improvement of modern castor varieties.展开更多
The advantages of both the length and accuracy of high-fidelity(HiFi)reads enable chromosome-scale haplotype-resolved genome assembly.In this study,we sequenced a cell line named HJ,established from a Chinese Han male...The advantages of both the length and accuracy of high-fidelity(HiFi)reads enable chromosome-scale haplotype-resolved genome assembly.In this study,we sequenced a cell line named HJ,established from a Chinese Han male individual by using HiFi and Hi-C.We assembled two high-quality haplotypes of the HJ genome(haplotype 1(H1):3.1 Gb,haplotype 2(H2):2.9 Gb).The continuity(H1:contig N50=28.2 Mb,H2:contig N50=25.9 Mb)and completeness(BUSCO:H1=94.9%,H2=93.5%)are substantially better than those of other Chinese genomes,for example,HX1,NH1.0,and YH2.0.By comparing HJ genome with GRCh38,we reported the mutation landscape of HJ and found that 176 and 213 N-gaps were filled in H1 and H2,respectively.In addition,we detected 12.9 Mb and 13.4 Mb novel sequences containing 246 and 135 protein-coding genes in H1 and H2,respectively.Our results demonstrate the advantages of HiFi reads in haplotype-resolved genome assembly and provide two high-quality haplotypes of a potential Chinese genome as a reference for the Chinese Han population.展开更多
Microtus fortis is the only mammalian host that exhibits intrinsic resistance against Schistosoma japonicum infection.However,the underlying molecular mechanisms of this resistance are not yet known.Here,we perform th...Microtus fortis is the only mammalian host that exhibits intrinsic resistance against Schistosoma japonicum infection.However,the underlying molecular mechanisms of this resistance are not yet known.Here,we perform the first de novo genome assembly of M.fortis,comprehensive gene annotation analysis,and evolution analysis.Furthermore,we compare the recovery rate of schistosomes,pathological changes,and liver transcriptomes between M.fortis and mice at different time points after infection.We observe that the time and type of immune response in M.fortis are different from those in mice.M.fortis activates immune and inflammatory responses on the 10th day post infection,such as leukocyte extravasation,antibody activation,Fc-gamma receptor-mediated phagocytosis,and the interferon signaling cascade,which play important roles in preventing the development of schistosomes.In contrast,an intense immune response occurrs in mice at the late stages of infection and could not eliminate schistosomes.Infected mice suffer severe pathological injury and continuous decreases in cell cycle,lipid metabolism,and other functions.Our findings offer new insights into the intrinsic resistance mechanism of M.fortis against schistosome infection.The genome sequence also provides the basis for future studies of other important traits in M.fortis.展开更多
The rapid development of high-throughput sequencing technologies has led to a dramatic decrease in the money and time required for de novo genome sequencing or genome resequencing projects, with new genome sequences c...The rapid development of high-throughput sequencing technologies has led to a dramatic decrease in the money and time required for de novo genome sequencing or genome resequencing projects, with new genome sequences constantly released every week. Among such projects, the plethora of updated genome assemblies induces the requirement of versiondependent annotation files and other compatible public dataset for downstream analysis. To handlethese tasks in an efficient manner, we developed the reference-based genome assembly and annotation tool(RGAAT), a flexible toolkit for resequencing-based consensus building and annotation update. RGAAT can detect sequence variants with comparable precision, specificity, and sensitivity to GATK and with higher precision and specificity than Freebayes and SAMtools on four DNAseq datasets tested in this study. RGAAT can also identify sequence variants based on cross-cultivar or cross-version genomic alignments. Unlike GATK and SAMtools/BCFtools, RGAAT builds the consensus sequence by taking into account the true allele frequency. Finally, RGAAT generates a coordinate conversion file between the reference and query genomes using sequence variants and supports annotation file transfer. Compared to the rapid annotation transfer tool(RATT),RGAAT displays better performance characteristics for annotation transfer between different genome assemblies, strains, and species. In addition, RGAAT can be used for genome modification,genome comparison, and coordinate conversion. RGAAT is available at https://sourceforge.net/projects/rgaat/and https://github.com/wushyer/RGAAT;2 at no cost.展开更多
Background:De novo genome assembly relies on two kinds of graphs:de Bruijn graphs and overlap graphs.Overlap graphs are the basis for the Celera assembler,while de Bruijn graphs have become the dominant technical devi...Background:De novo genome assembly relies on two kinds of graphs:de Bruijn graphs and overlap graphs.Overlap graphs are the basis for the Celera assembler,while de Bruijn graphs have become the dominant technical device in the last decade.Those two kinds of graphs are collectively called assembly graphs.Results:In this review,we discuss the most recent advances in the problem of constructing,representing and navigating assembly graphs,focusing on very large datasets.We will also explore some computational techniques,such as the Bloom filter,to compactly store graphs while keeping all functionalities intact.Conclusions:We complete our analysis with a discussion on the algorithmic issues of assembling from long reads(eg.,PacBio and Oxford Nanopore).Finally,we present some of the most relevant open problems in this field.展开更多
The Chinese sucker,Myxocyprinus asiaticus(M.asiaticus,Catostomidae,Cypriniformes),is the only living species of Catostomidae in Asia.There are more than 75 species of this family in North America.The fossil record of ...The Chinese sucker,Myxocyprinus asiaticus(M.asiaticus,Catostomidae,Cypriniformes),is the only living species of Catostomidae in Asia.There are more than 75 species of this family in North America.The fossil record of this group dates back to the early Eocene.As the Chinese sucker is located at the base of the Cyprinoidei phylogeny,this species is also important in clarifying the evolutionary relationships within Cyprinoidei.Here,we assembled a high-quality genome of the Chinese sucker,contig N50(40.26 Mb),which is nearly ten times longer than the previous version(4.19 Mb).Phylogenetic analysis identified that Chinese sucker together with Cyprinidae groups are paraphyletic with respect to Cobitoidea.The specific whole genome duplication event of the Chinese sucker was estimated to have occurred~25.9 million years ago.Analysis of population historical changes indicated a trend of reduction for the Chinese sucker and T.tibetana.Since Dlx genes play a key role in Cypriniformes pharyngeal teeth development,we conducted a genome-wide identification of Dlx genes,and found that these genes were doubled in whole genome duplication events,followed by the loss of specific copies.Transcriptome results showed that the expression levels of these paralogous genes were similar.This genomic resource provides useful information for the protection of Chinese sucker and functional study of Dlx genes.展开更多
Rubus corchorifolius(Shanmei or mountain berry,2n=14)is widely distributed in China,and its fruits possess high nutritional and medicinal values.Here,we reported a highquality chromosome-scale genome assembly of Shanm...Rubus corchorifolius(Shanmei or mountain berry,2n=14)is widely distributed in China,and its fruits possess high nutritional and medicinal values.Here,we reported a highquality chromosome-scale genome assembly of Shanmei,with contig size of 215.69 Mb and 26,696 genes.Genome comparison among Rosaceae species showed that Shanmei and Fupenzi(Rubus chingii Hu)were most closely related,followed by blackberry(Rubus occidentalis),and that environmental adaptation-related genes were expanded in the Shanmei genome.Further resequencing of 101 samples of Shanmei collected from four regions in the provinces of Yunnan,Hunan,Jiangxi,and Sichuan in China revealed that among these samples,the Hunan population of Shanmei possessed the highest diversity and represented the more ancestral population.Moreover,the Yunnan population underwent strong selection based on the nucleotide diversity,linkage disequilibrium,and historical effective population size analyses.Furthermore,genes from candidate genomic regions that showed strong divergence were significantly enriched in the flavonoid biosynthesis and plant hormone signal transduction pathways,indicating the genetic basis of adaptation of Shanmei to the local environment.The high-quality assembled genome and the variome dataset of Shanmei provide valuable resources for breeding applications and for elucidating the genome evolution and ecological adaptation of Rubus species.展开更多
Introduction:Genome sequence plays an important role in both basic and applied studies.Gossypium raimondii,the putative contributor of the D subgenome of upland cotton(G.hirsutum,highlights the need to improve the gen...Introduction:Genome sequence plays an important role in both basic and applied studies.Gossypium raimondii,the putative contributor of the D subgenome of upland cotton(G.hirsutum,highlights the need to improve the genome quality rapidly and efficiently.Methods:We performed Hi-C sequencing of G.raimondii and reassembled its genome based on a set of new Hi-C data and previously published scaffolds.We also compared the reassembled genome sequenee with the previously published G raimondii genomes for gene and genome sequence collinearity.Result:A total of 9842%of scaffold sequences were clustered successfully,among which 99.72%of the clustered sequences were ordered and 99.92%of the ordered sequences were oriented with high-quality.Further evaluation of results by heat-map and collinearity analysis revealed that the current reassembled genome is significantly improved than the previous one(Nat Genet 44:98-1103,2012).Conclusion:This improvement in G raimondii genome not only provides a better reference to increase study efficiency but also offers a new way to assemble cotton genomes.Furthermore,Hi-C data of G.raimondii may be used for 3D structure research or regulating analysis.展开更多
The ancient crop broomcorn millet(Panicum miliaceum L.)is an indispensable orphan crop in semi-arid regions due to its short life cycle and excellent abiotic stress tolerance.These advantages make it an important alte...The ancient crop broomcorn millet(Panicum miliaceum L.)is an indispensable orphan crop in semi-arid regions due to its short life cycle and excellent abiotic stress tolerance.These advantages make it an important alternative crop to increase food security and achieve the goal of zero hunger,particularly in light of the uncertainty of global climate change.However,functional genomic and biotechnological research in broomcorn millet has been hampered due to a lack of genetic tools such as transformation and genome-editing techniques.Here,we successfully performed genome editing of broomcorn millet.We identified an elite variety,Hongmi,that produces embryogenic callus and has high shoot regeneration ability in in vitro culture.We established an Agrobacterium tumefaciens-mediated genetic transformation protocol and a clustered regularly interspaced short palindromic repeats(CRISPR)/Cas9-mediated genome-editing system for Hongmi.Using these techniques,we produced herbicide-resistant transgenic plants and edited phytoene desaturase(Pm PDS),which is involved in chlorophyll biosynthesis.To facilitate the rapid adoption of Hongmi as a model line for broomcorn millet research,we assembled a near-complete genome sequence of Hongmi and comprehensively annotated its genome.Together,our results open the door to improving broomcorn millet using biotechnology.展开更多
Houttuynia cordata,also known as Yuxingcao in Chinese,is a perennial herb in the Saururaceae family.It is highly regarded for its medicinal properties,particularly in treating respiratory infections and inflammatory c...Houttuynia cordata,also known as Yuxingcao in Chinese,is a perennial herb in the Saururaceae family.It is highly regarded for its medicinal properties,particularly in treating respiratory infections and inflammatory conditions,as well as boosting the human immune system.However,a lack of genomic information has hindered research on the functional genomics and potential improvements of H.cordata.In this study,we present a near-complete assembly of H.cordata genome and investigate the biosynthetic pathway of flavonoids,specifically quercetin,using genomics,transcriptomics,and metabolomics analyses.The genome of H.cordata diverged from that of Saururus chinensis around 33.4 million years ago;it consists of 2.24 Gb with 76 chromosomes(4n=76)and has undergone three whole-genome duplication(WGD)events.These WGDs played a crucial role in shaping the H.cordata genome and influencing the gene families associated with its medicinal properties.Through metabolomics and transcriptomics analyses,we identified key genes involved in the b-oxidation process for biosynthesis of houttuynin,one of the volatile oils responsible for the plant’s fishy smell.In addition,using the reference genome,we identified genes involved in flavonoid biosynthesis,particularly quercetin metabolism,in H.cordata.This discovery has important implications for understanding the regulatory mechanisms that underlie production of active pharmaceutical ingredients in traditional Chinese medicine.Overall,the high-quality genome assembly of H.cordata serves as a valuable resource for future functional genomics research and provides a solid foundation for genetic improvement of H.cordata for the benefit of human health.展开更多
Populus alba × P.glandulosa clone 84 K,derived from South Korea,is widely cultivated in China and used as a model in the molecular research of woody plants because of hi gh gene transformation efficiency.Here,we ...Populus alba × P.glandulosa clone 84 K,derived from South Korea,is widely cultivated in China and used as a model in the molecular research of woody plants because of hi gh gene transformation efficiency.Here,we combined63-fold coverage Illumina short reads and 126-fold coverage PacBio long reads to assemble the genome.Due to the hi gh heterozygosity level at 2.1% estimated by k-mer analysis,we exploited TrioCanu for genome assembly.The PacBio clean subreads of P.alba × P.glandulosa were separated into two parts according to the similarities,compared with the parental genomes of P.alba and P.glandulosa.The two parts of the subreads were assembled to two sets of subgenomes comprising subgenome A(405.31 Mb,from P.alba)and subgenome G(376.05 Mb,from P.glandulosa) with the contig N50 size of 5.43 Mb and 2.15 Mb,respectively.A high-quality P.alba × P.glandulosa genome assembly was obtained.The genome size was 781.36 Mb with the contig N50 size of 3.66 Mb and the longest contig was 19.47 Mb.In addition,a total of 176.95 Mb(43.7%),152.37 Mb(40.5%)of repetitive elements were identified and a total of 38,701 and 38,449 protein-coding genes were predicted in subgenomes A and G,respectively.For functional annotation,96.98% of subgenome A and 96.96% of subgenome G genes were annotated with public databases.This de novo assembled genome will facilitate systematic and comprehensive study,such as multi-omics analysis,in the model tree P.alba X P.glandulosa.展开更多
基金supported by the Chinese Academy of Agricultural Sciences Innovation Project(Grant No.CAASASTIP-2013CNRRI)Fundamental Research Funds for Central Public Welfare Research Institutes of Chinese Rice Research Institute(Grant No.CPSIBRF-CNRRI-202102)。
文摘Accurate genomic information is essential for advancing genetic breeding research in specific rice varieties.This study presented a gapless genome assembly of the indica rice cultivar Zhonghui 8015(ZH8015)using Pac Bio HiFi,Hi-C,and ONT(Oxford Nanopore Technologies)ultra-long sequencing technologies,annotating 43037 gene structures.Subsequently,utilizing this genome along with transcriptomic and metabolomic techniques,we explored ZH8015's response to brown planthopper(BPH)infestation.Continuous transcriptomic sampling indicated significant changes in gene expression levels around 48 h after BPH feeding.Enrichment analysis revealed particularly significant alterations in genes related to reactive oxygen species scavenging and cell wall formation.Metabolomic results demonstrated marked increases in levels of several monosaccharides,which are components of the cell wall and dramatic changes in flavonoid contents.Omics association analysis identified differentially expressed genes associated with key metabolites,shedding light on ZH8015's response to BPH infestation.In summary,this study constructed a reliable genome sequence resource for ZH8015,and the preliminary multi-omics results will guide future insect-resistant breeding research.
基金the China Agriculture Research System(CARS-02-77)the Shaanxi Province Research and Development Project(2021LLRH-07)the Yangling Seed Industry Innovation Center Project(YLZY-YM-01).
文摘Superior inbred lines are central to maize breeding as sources of natural variation.Although many elite lines have been sequenced,less sequencing attention has been paid to newly developed lines.We constructed a genome assembly of the elite inbred line KA105,which has recently been developed by an arti-ficial breeding population named Shaan A and has shown desirable characteristics for breeding.Its pedigree showed genetic divergence from B73 and other lines in its pedigree.Comparison with the B73 reference genome revealed extensive structural variation,58 presence/absence variation(PAV)genes,and 1023 expanded gene families,some of which may be associated with disease resistance.A network-based integrative analysis of stress-induced transcriptomes identified 13 KA105-specific PAV genes,of which eight were induced by at least one kind of stress,participating in gene modules responding to stress such as drought and southern leaf blight disease.More than 200,000 gene pairs were differentially correlated between KA105 and B73 during kernel development.The KA105 reference genome and transcriptome atlas are a resource for further germplasm improvement and surveys of maize genomic variation and gene function.
基金supported by the National Natural Science Foundation of China(31871637,32072073,and 32001500)the Project of Transgenic New Variety Cultivation(2016ZX08003003)。
文摘The current assembled maize genomes cannot represent the broad genetic diversity of maize germplasms.Acquiring more genome sequences is critical for constructing a pan-genome and elucidating the linkage between genotype and phenotype in maize.Here we describe the genome sequence and annotation of A188,a maize inbred line with high phenotypic variation relative to other lines,acquired by single-molecule sequencing and optical genome mapping.We assembled a 2210-Mb genome with a scaffold N50 size of 11.61 million bases(Mb),compared to 9.73 Mb for B73 and 10.2 Mb for Mo17.Based on the B73_Ref Gen_V4 genome,295 scaffolds(2084.35 Mb,94.30%of the final genome assembly)were anchored and oriented on ten chromosomes.Comparative analysis revealed that~30%of the predicted A188 genes showed large structural divergence from B73,Mo17,and W22 genomes,which causes high protein divergence and may lead to phenotypic variation among the four inbred lines.As a line with high embryonic callus(EC)induction capacity,A188 provides a convenient tool for elucidating the molecular mechanism underlying the formation of EC in maize.Combining our new A188 genome with previously reported QTL and RNA sequencing data revealed eight genes with large structural variation and two differentially expressed genes playing potential roles in maize EC induction.
基金Jianghan University,Grant/Award Number:2023XKZ024National Forestry and Grassland Administration,Grant/Award Number:KJZXXP202314。
文摘Background:Arundo donax L.has great potential as an energy crop due to its high biomass yield and broad adaptability,while lack of a reference genome is a hindrance to genetic improvement efforts for this species.Methods:Genome assembly of A.donax was conducted by utilizing PacBio SMRT sequencing and high-throughput chromosome conformation capture technology,with further analysis exploring the plant's ploidy,whole-genome duplication event,and evolutionary history through comparative genomics.Results:The genome assembly of A.donax consists of 1.30 Gb with a contig N50 size of 33.15 Mb.A total of 74403 gene models were identified,with over 90%of genes being functionally annotated.Karyotype and synteny analyses revealed that A.donax is an autoalloenneaploid(3n=9x=108)and has experienced significant gene family expansion and two whole-genome duplication events during its evolutionary history.Furthermore,utilizing the genome assembly,a variety of salinity stress-related genes were uncovered through the analysis of public RNA-seq data.Conclusions:This study presents the initial chromosome-scale genome assembly of A.donax,which will advance genetic comprehension and support the genetic enhancement of this important energy crop.
基金supported by the National Key Research and Development Project Program of China(2022YFC3400300,2019YFE0109600)the China Postdoctoral Science Foundation(2021M701584).
文摘With the rapid development of sequencing technologies,especially the maturity of third-generation sequencing technologies,there has been a significant increase in the number and quality of published genome assemblies.The emergence of these high-quality genomes has raised higher requirements for genome evaluation.Although numerous computational methods have been developed to evaluate assembly quality from various perspectives,the selective use of these evaluation methods can be arbitrary and inconvenient for fairly comparing the assembly quality.To address this issue,we have developed the Genome Assembly Evaluating Pipeline(GAEP),which provides a comprehensive assessment pipeline for evaluating genome quality from multiple perspectives,including continuity,completeness,and correctness.Additionally,GAEP includes new functions for detecting misassemblies and evaluating the assembly redundancy,which performs well in our testing.GAEP is publicly available at https://github.com/zyoptimistic/GAEP under the GPL3.0 License.With GAEP,users can quickly obtain accurate and reliable evaluation results,facilitating the comparison and selection of high-quality genome assemblies.
基金supported by grants from the Major Special Project of Fujian Province(2021NZ029009)the Natural Science foundation of Fujian Province(2019J01665).
文摘JUJUNCAO(Cenchrus fungigraminus;2n=4x=28)is a Cenchrus grass with the highest biomass production among cultivated plants,and it can be used for mushroom cultivation,animal feed,and biofuel production.Here,we report a nearly complete genome assembly of JUJUNCAO and reveal that JUJUNCAO is an allopolyploid that originated2.7 million years ago(mya).Its genome consists of two subgenomes,and subgenome A shares high collinear synteny with pearl millet.We also investigated the genome evolution of JUJUNCAO and suggest that the ancestral karyotype of Cenchrus split into the A and B ancestral karyotypes of JUJUNCAO.Comparative transcriptome and DNA methylome analyses revealed functional divergence of homeologous gene pairs between the two subgenomes,which was a further indication of asymmetric DNA methylation.The three types of centromeric repeat in the JUJUNCAO genome(CEN137,CEN148,and CEN156)may have evolved independently within each subgenome,with some introgressions of CEN156 from the B to the A subgenome.We investigated the photosynthetic characteristics of JUJUNCAO,revealing its typical C4 Kranz anatomy and high photosynthetic efficiency.NADP-ME and PEPCK appear to cooperate in the major C4 decarboxylation reaction of JUJUNCAO,which is different from other C4 photosynthetic subtypes and may contribute to its high photosynthetic efficiency and biomass yield.Taken together,our results provide insights into the highly efficient photosynthetic mechanism of JUJUNCAO and provide a valuable reference genome for future genetic and evolutionary studies,as well as genetic improvement of Cenchrus grasses.
基金supported by grants from the Zhejiang Provincial Natural Science Foundation of China(Grant No.LTY22C030002)the National Natural Science Foundation of China(Grant No.32001113)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ19C030001)。
文摘Plants of the Caprifoliaceae family are widely cultivated worldwide as ornamental plants owing to their numerous,sweet-smelling,beautiful flowers and fruits.Heptacodium miconioides Rehd.,a member of the family,is endemic to eastern China and is cultivated as a popular ornamental plant in North America and European countries.It has a rather novel and beautiful trait of high horticultural value,that is,its sepals persist and enlarge,turning purplish red.Here,we report the chromosome-level genome assembly of H.miconioides to understand its evolution and floral characteristics.The 622.28 Mb assembled genome harbored a shared whole-genome duplication with a related species,Lonicera japonica.Comparative genomic analysis suggested that chromosome fission events following genome duplication underlie the unusual chromosome number of these two species,as well as chromosome fission of another five chromosomes in H.miconioides,giving rise to a haploid chromosome number of 14(versus 9 in L.japonica).In addition,based on transcriptome and chloroplast genome analysis of 17 representative species in the Caprifoliaceae,we assumed that large structural variations in the chromosomes of H.miconioides were not caused by hybridization.Changes in the candidate genes of the MADS-box family were detected in the H.miconioides genome,including AP1-,AP3-,and SEPexpanded,which might underlie the sepal elongation and development in this species.The current findings provided a critical resource for genome evolution studies in Caprifoliaceae and it was an example of how multi-omics data can elucidate the regulation of important ornamental traits.
基金the Agricultural Science and Technology Innovation Program,the Elite Young Scientists Program of CAAS,the Science Technology and Innovation Committee of Shenzhen Municipality(KQJSCX20180323140312935,AGIS-ZDKY202004)the Dapeng New District Special Fund for Industrial Development(KY20150113)。
文摘High-quality rice reference genomes have accelerated the comprehensive identification of genome-wide variations and research on functional genomics and breeding.Tian-you-hua-zhan has been a leading hybrid in China over the past decade.Here,de novo genome assembly strategy optimization for the rice indica lines Huazhan(HZ)and Tianfeng(TF),including sequencing platforms,assembly pipelines and sequence depth,was carried out.The PacBio and Nanopore platforms for long-read se-quencing were utilized,with the Canu,wtdbg2,SMARTdenovo,Flye,Canu-wtdbg2,Canu-SMARTdenovo and Canu-Flye assemblers.The combination of PacBio and Canu was optimal,considering the contig N50 length,contig number,assembled genome size and polishing process.The assembled contigs were scaffolded with Hi-C data,resulting in two“golden quality”rice reference genomes,and evaluated using the scaffold N50,BUSCO,and LTR assembly index.Furthermore,42,625 and 41,815 non-transposable element genes were annotated for HZ and TF,respectively.Based on our assembly of HZ and TF,as well as Zhenshan97,Minghui63,Shuhui498 and 9311,comprehensive variations were identified using Nipponbare as a reference.The de novo assembly strategy for rice we optimized and the“golden quality”rice genomes we produced for HZ and TF will benefit rice genomics and breeding research,especially with respect to uncovering the genomic basis of the elite traits of HZ and TF.
基金supported by the National Natural Science Foundation of China(Grant Nos.31971758 to QY and 32071865 to RL)the Collaborative Research Key Project between China and EU(Grant No.2017YFE0111000)+2 种基金the China Agriculture Research System of MOF and MARA(Grant No.CARS-34)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(Grant No.ASTIP-IAS14)the Key Projects in Science and Technology of Inner Mongolia,China(Grant No.2021ZD0031)。
文摘Alfalfa(Medicago sativa L.)is the most important legume forage crop worldwide with high nutritional value and yield.For a long time,the breeding of alfalfa was hampered by lacking reliable information on the autotetraploid genome and molecular markers linked to important agronomic traits.We herein reported the de novo assembly of the allele-aware chromosome-level genome of Zhongmu-4,a cultivar widely cultivated in China,and a comprehensive database of genomic variations based on resequencing of 220 germplasms.Approximate 2.74 Gb contigs(N50 of 2.06 Mb),accounting for 88.39%of the estimated genome,were assembled,and 2.56 Gb contigs were anchored to 32 pseudo-chromosomes.A total of 34,922 allelic genes were identified from the allele-aware genome.We observed the expansion of gene families,especially those related to the nitrogen metabolism,and the increase of repetitive elements including transposable elements,which probably resulted in the increase of Zhongmu-4 genome compared with Medicago truncatula.Population structure analysis revealed that the accessions from Asia and South America had relatively lower genetic diversity than those from Europe,suggesting that geography may influence alfalfa genetic divergence during local adaption.Genome-wide association studies identified 101 single nucleotide polymorphisms(SNPs)associated with 27 agronomic traits.Two candidate genes were predicted to be correlated with fall dormancy and salt response.We believe that the alleleaware chromosome-level genome sequence of Zhongmu-4 combined with the resequencing data of the diverse alfalfa germplasms will facilitate genetic research and genomics-assisted breeding in variety improvement of alfalfa.
基金supported by the National Key R&D Program of China(Grant No.2018YFA0901800)the National Natural Science Foundation of China(Grant No.32072101)+1 种基金the Guangdong Basic and Applied Basic Research Foundation,China(Grant No.2019A1515111150)the Shenzhen Science and Technology Program,China(Grant No.KQTD20180411143628272)。
文摘Wild castor grows in the high-altitude tropical desert of the African Plateau,a region known for high ultraviolet radiation,strong light,and extremely dry condition.To investigate the potential genetic basis of adaptation to both highland and tropical deserts,we generated a chromosome-level genome sequence assembly of the wild castor accession WT05,with a genome size of 316 Mb,a scaffold N50 of 31.93 Mb,and a contig N50 of 8.96 Mb,respectively.Compared with cultivated castor and other Euphorbiaceae species,the wild castor exhibits positive selection and gene family expansion for genes involved in DNA repair,photosynthesis,and abiotic stress responses.Genetic variations associated with positive selection were identified in several key genes,such as LIG1,DDB2,and RECG1,involved in nucleotide excision repair.Moreover,a study of genomic diversity among wild and cultivated accessions revealed genomic regions containing selection signatures associated with the adaptation to extreme environments.The identification of the genes and alleles with selection signatures provides insights into the genetic mechanisms underlying the adaptation of wild castor to the high-altitude tropical desert and would facilitate direct improvement of modern castor varieties.
基金the National Key R&D Program of China(2022YFC3400300)the National Natural Science Foundation of China(32125009,62172325,32070663)+1 种基金the National Key R&D Program of China(2017YFC0906501)the Key Construction Program of the National‘985’Project,and the Fundamental Research Funds for the Central Universities.
文摘The advantages of both the length and accuracy of high-fidelity(HiFi)reads enable chromosome-scale haplotype-resolved genome assembly.In this study,we sequenced a cell line named HJ,established from a Chinese Han male individual by using HiFi and Hi-C.We assembled two high-quality haplotypes of the HJ genome(haplotype 1(H1):3.1 Gb,haplotype 2(H2):2.9 Gb).The continuity(H1:contig N50=28.2 Mb,H2:contig N50=25.9 Mb)and completeness(BUSCO:H1=94.9%,H2=93.5%)are substantially better than those of other Chinese genomes,for example,HX1,NH1.0,and YH2.0.By comparing HJ genome with GRCh38,we reported the mutation landscape of HJ and found that 176 and 213 N-gaps were filled in H1 and H2,respectively.In addition,we detected 12.9 Mb and 13.4 Mb novel sequences containing 246 and 135 protein-coding genes in H1 and H2,respectively.Our results demonstrate the advantages of HiFi reads in haplotype-resolved genome assembly and provide two high-quality haplotypes of a potential Chinese genome as a reference for the Chinese Han population.
基金This work was supported by the Key Project in the National Science&Technology Pillar Program from the Ministry of Science and Technology(2015BAI09B04)the National Natural Science Foundation of China(31872256,31472188)+2 种基金the National Key Research and Development Program of China(2017YFD0501306)the Science and Technology Service Network Initiative of Chinese Academy of Sciences(KFJ-STS-QYZD-126,ZDBS-SSW-DQC-02)CAS Youth Innovation Promotion Association,and SA-SIBS Scholarship Program.
文摘Microtus fortis is the only mammalian host that exhibits intrinsic resistance against Schistosoma japonicum infection.However,the underlying molecular mechanisms of this resistance are not yet known.Here,we perform the first de novo genome assembly of M.fortis,comprehensive gene annotation analysis,and evolution analysis.Furthermore,we compare the recovery rate of schistosomes,pathological changes,and liver transcriptomes between M.fortis and mice at different time points after infection.We observe that the time and type of immune response in M.fortis are different from those in mice.M.fortis activates immune and inflammatory responses on the 10th day post infection,such as leukocyte extravasation,antibody activation,Fc-gamma receptor-mediated phagocytosis,and the interferon signaling cascade,which play important roles in preventing the development of schistosomes.In contrast,an intense immune response occurrs in mice at the late stages of infection and could not eliminate schistosomes.Infected mice suffer severe pathological injury and continuous decreases in cell cycle,lipid metabolism,and other functions.Our findings offer new insights into the intrinsic resistance mechanism of M.fortis against schistosome infection.The genome sequence also provides the basis for future studies of other important traits in M.fortis.
基金supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA08020102)National Natural Science Foundation of China (Grant Nos. 81701071, 31501042, 31271385, and 31200957)+2 种基金Shenzhen Science and Technology Program (Grant No. JCYJ20170306171013613),ChinaKing Abdulaziz City for Science and Technology (KACSTGrant No. 1035-35),Kingdom of Saudi Arabia
文摘The rapid development of high-throughput sequencing technologies has led to a dramatic decrease in the money and time required for de novo genome sequencing or genome resequencing projects, with new genome sequences constantly released every week. Among such projects, the plethora of updated genome assemblies induces the requirement of versiondependent annotation files and other compatible public dataset for downstream analysis. To handlethese tasks in an efficient manner, we developed the reference-based genome assembly and annotation tool(RGAAT), a flexible toolkit for resequencing-based consensus building and annotation update. RGAAT can detect sequence variants with comparable precision, specificity, and sensitivity to GATK and with higher precision and specificity than Freebayes and SAMtools on four DNAseq datasets tested in this study. RGAAT can also identify sequence variants based on cross-cultivar or cross-version genomic alignments. Unlike GATK and SAMtools/BCFtools, RGAAT builds the consensus sequence by taking into account the true allele frequency. Finally, RGAAT generates a coordinate conversion file between the reference and query genomes using sequence variants and supports annotation file transfer. Compared to the rapid annotation transfer tool(RATT),RGAAT displays better performance characteristics for annotation transfer between different genome assemblies, strains, and species. In addition, RGAAT can be used for genome modification,genome comparison, and coordinate conversion. RGAAT is available at https://sourceforge.net/projects/rgaat/and https://github.com/wushyer/RGAAT;2 at no cost.
文摘Background:De novo genome assembly relies on two kinds of graphs:de Bruijn graphs and overlap graphs.Overlap graphs are the basis for the Celera assembler,while de Bruijn graphs have become the dominant technical device in the last decade.Those two kinds of graphs are collectively called assembly graphs.Results:In this review,we discuss the most recent advances in the problem of constructing,representing and navigating assembly graphs,focusing on very large datasets.We will also explore some computational techniques,such as the Bloom filter,to compactly store graphs while keeping all functionalities intact.Conclusions:We complete our analysis with a discussion on the algorithmic issues of assembling from long reads(eg.,PacBio and Oxford Nanopore).Finally,we present some of the most relevant open problems in this field.
基金supported by grants from the National Natural Science Foundation of China(32170438)to C.FThe research was supported by the Wuhan Branch,Supercomputing Center,Chinese Academy of Sciences,China.We thank Dr Dengqiang Wang from Yangtze River Fisheries Research Institute,Chinese Academy of Fishery Sciences for help with sampling.
文摘The Chinese sucker,Myxocyprinus asiaticus(M.asiaticus,Catostomidae,Cypriniformes),is the only living species of Catostomidae in Asia.There are more than 75 species of this family in North America.The fossil record of this group dates back to the early Eocene.As the Chinese sucker is located at the base of the Cyprinoidei phylogeny,this species is also important in clarifying the evolutionary relationships within Cyprinoidei.Here,we assembled a high-quality genome of the Chinese sucker,contig N50(40.26 Mb),which is nearly ten times longer than the previous version(4.19 Mb).Phylogenetic analysis identified that Chinese sucker together with Cyprinidae groups are paraphyletic with respect to Cobitoidea.The specific whole genome duplication event of the Chinese sucker was estimated to have occurred~25.9 million years ago.Analysis of population historical changes indicated a trend of reduction for the Chinese sucker and T.tibetana.Since Dlx genes play a key role in Cypriniformes pharyngeal teeth development,we conducted a genome-wide identification of Dlx genes,and found that these genes were doubled in whole genome duplication events,followed by the loss of specific copies.Transcriptome results showed that the expression levels of these paralogous genes were similar.This genomic resource provides useful information for the protection of Chinese sucker and functional study of Dlx genes.
基金supported by the grants from the Biodiversity Survey and Assessment Project of the Ministry of Ecology and Environment, China (Grant No. 2019HJ2096001006)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciencesthe Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs, China
文摘Rubus corchorifolius(Shanmei or mountain berry,2n=14)is widely distributed in China,and its fruits possess high nutritional and medicinal values.Here,we reported a highquality chromosome-scale genome assembly of Shanmei,with contig size of 215.69 Mb and 26,696 genes.Genome comparison among Rosaceae species showed that Shanmei and Fupenzi(Rubus chingii Hu)were most closely related,followed by blackberry(Rubus occidentalis),and that environmental adaptation-related genes were expanded in the Shanmei genome.Further resequencing of 101 samples of Shanmei collected from four regions in the provinces of Yunnan,Hunan,Jiangxi,and Sichuan in China revealed that among these samples,the Hunan population of Shanmei possessed the highest diversity and represented the more ancestral population.Moreover,the Yunnan population underwent strong selection based on the nucleotide diversity,linkage disequilibrium,and historical effective population size analyses.Furthermore,genes from candidate genomic regions that showed strong divergence were significantly enriched in the flavonoid biosynthesis and plant hormone signal transduction pathways,indicating the genetic basis of adaptation of Shanmei to the local environment.The high-quality assembled genome and the variome dataset of Shanmei provide valuable resources for breeding applications and for elucidating the genome evolution and ecological adaptation of Rubus species.
文摘Introduction:Genome sequence plays an important role in both basic and applied studies.Gossypium raimondii,the putative contributor of the D subgenome of upland cotton(G.hirsutum,highlights the need to improve the genome quality rapidly and efficiently.Methods:We performed Hi-C sequencing of G.raimondii and reassembled its genome based on a set of new Hi-C data and previously published scaffolds.We also compared the reassembled genome sequenee with the previously published G raimondii genomes for gene and genome sequence collinearity.Result:A total of 9842%of scaffold sequences were clustered successfully,among which 99.72%of the clustered sequences were ordered and 99.92%of the ordered sequences were oriented with high-quality.Further evaluation of results by heat-map and collinearity analysis revealed that the current reassembled genome is significantly improved than the previous one(Nat Genet 44:98-1103,2012).Conclusion:This improvement in G raimondii genome not only provides a better reference to increase study efficiency but also offers a new way to assemble cotton genomes.Furthermore,Hi-C data of G.raimondii may be used for 3D structure research or regulating analysis.
基金funded by grants from the National Key Research and Development Program of China(2022YFD1400800,2021YFF1000101-4)the Innovation Program of the Chinese Academy of Agricultural Sciences+2 种基金the National Natural Science Foundation of China(32172093)the China Postdoctoral Science Foundation funded project(2023M743843)Initiative Scientific Research Program,Institute of Zoology,Chinese Academy of Sciences(2023IOZ0203)。
文摘The ancient crop broomcorn millet(Panicum miliaceum L.)is an indispensable orphan crop in semi-arid regions due to its short life cycle and excellent abiotic stress tolerance.These advantages make it an important alternative crop to increase food security and achieve the goal of zero hunger,particularly in light of the uncertainty of global climate change.However,functional genomic and biotechnological research in broomcorn millet has been hampered due to a lack of genetic tools such as transformation and genome-editing techniques.Here,we successfully performed genome editing of broomcorn millet.We identified an elite variety,Hongmi,that produces embryogenic callus and has high shoot regeneration ability in in vitro culture.We established an Agrobacterium tumefaciens-mediated genetic transformation protocol and a clustered regularly interspaced short palindromic repeats(CRISPR)/Cas9-mediated genome-editing system for Hongmi.Using these techniques,we produced herbicide-resistant transgenic plants and edited phytoene desaturase(Pm PDS),which is involved in chlorophyll biosynthesis.To facilitate the rapid adoption of Hongmi as a model line for broomcorn millet research,we assembled a near-complete genome sequence of Hongmi and comprehensively annotated its genome.Together,our results open the door to improving broomcorn millet using biotechnology.
基金funded by the National Natural Science Foundation of China,China(grant number 32360074)the Guizhou Provincial Natural Science Foundation of Department of Education,China([2022]077)+1 种基金The Karst Mountain Ecological Security Engineering Research Center,China(KY[2021]007)the Joint Fund of the National Natural Science Foundation of China and the Karst Science Research Center of Guizhou Province,China(U1812401).
文摘Houttuynia cordata,also known as Yuxingcao in Chinese,is a perennial herb in the Saururaceae family.It is highly regarded for its medicinal properties,particularly in treating respiratory infections and inflammatory conditions,as well as boosting the human immune system.However,a lack of genomic information has hindered research on the functional genomics and potential improvements of H.cordata.In this study,we present a near-complete assembly of H.cordata genome and investigate the biosynthetic pathway of flavonoids,specifically quercetin,using genomics,transcriptomics,and metabolomics analyses.The genome of H.cordata diverged from that of Saururus chinensis around 33.4 million years ago;it consists of 2.24 Gb with 76 chromosomes(4n=76)and has undergone three whole-genome duplication(WGD)events.These WGDs played a crucial role in shaping the H.cordata genome and influencing the gene families associated with its medicinal properties.Through metabolomics and transcriptomics analyses,we identified key genes involved in the b-oxidation process for biosynthesis of houttuynin,one of the volatile oils responsible for the plant’s fishy smell.In addition,using the reference genome,we identified genes involved in flavonoid biosynthesis,particularly quercetin metabolism,in H.cordata.This discovery has important implications for understanding the regulatory mechanisms that underlie production of active pharmaceutical ingredients in traditional Chinese medicine.Overall,the high-quality genome assembly of H.cordata serves as a valuable resource for future functional genomics research and provides a solid foundation for genetic improvement of H.cordata for the benefit of human health.
基金supported by grants CAFYBB2017ZY001 and TGB2016001 from Fundamental Research Funds of the Chinese Academy of Forestry。
文摘Populus alba × P.glandulosa clone 84 K,derived from South Korea,is widely cultivated in China and used as a model in the molecular research of woody plants because of hi gh gene transformation efficiency.Here,we combined63-fold coverage Illumina short reads and 126-fold coverage PacBio long reads to assemble the genome.Due to the hi gh heterozygosity level at 2.1% estimated by k-mer analysis,we exploited TrioCanu for genome assembly.The PacBio clean subreads of P.alba × P.glandulosa were separated into two parts according to the similarities,compared with the parental genomes of P.alba and P.glandulosa.The two parts of the subreads were assembled to two sets of subgenomes comprising subgenome A(405.31 Mb,from P.alba)and subgenome G(376.05 Mb,from P.glandulosa) with the contig N50 size of 5.43 Mb and 2.15 Mb,respectively.A high-quality P.alba × P.glandulosa genome assembly was obtained.The genome size was 781.36 Mb with the contig N50 size of 3.66 Mb and the longest contig was 19.47 Mb.In addition,a total of 176.95 Mb(43.7%),152.37 Mb(40.5%)of repetitive elements were identified and a total of 38,701 and 38,449 protein-coding genes were predicted in subgenomes A and G,respectively.For functional annotation,96.98% of subgenome A and 96.96% of subgenome G genes were annotated with public databases.This de novo assembled genome will facilitate systematic and comprehensive study,such as multi-omics analysis,in the model tree P.alba X P.glandulosa.