Explore the vast range of titles available.

Roegneria yenchiana sp. nov. (Triticeae) is a new species collected from Shangri‐la of Yunnan Province in China based on morphological, cytological, and molecular data. It is morphologically characterized by one spikelet per node, rectangular glums, awns flanked by two short mucros in lemmas, distinguished from other species of Roegneria. The genomic in situ hybridization results indicate that R. yenchiana is an allotetraploid, and its genomic constitution is StY. Phylogenetic analyses based on multiple loci suggested that R. yenchiana is closely related to Pseudoroegneria and Roegneria, and the Pseudoroegneria served as the maternal donors during its polyploid speciation. Roegneria yenchiana sp. nov. (Triticeae) is described as a new species collected from the Hengduan Mountain Region. Roegneria yenchiana contains the StY genomic constitution. Pseudoroegneria served as the maternal donors during the polyploid speciation of Roegneria yenchiana.

Background The St -genome-sharing taxa are highly complex group of the species with the St nuclear genome and monophyletic origin in maternal lineages within the Triticeae, which contains more than half of polyploid species that distributed in a wide range of ecological habitats. While high level of genetic heterogeneity in plastome DNA due to a reticulate evolutionary event has been considered to link with the richness of the St -genome-sharing taxa, the relationship between the dynamics of diversification and molecular evolution is lack of understanding. Results Here, integrating 106 previously and 12 newly sequenced plastomes representing almost all previously recognized genomic types and genus of the Triticeae, this study applies phylogenetic reconstruction methods in combination with lineage diversification analyses, estimate of sequence evolution, and gene expression to investigate the dynamics of diversification in the tribe. Phylogenomic analysis confirmed previous phylogenetic relationships, with the St / E / V lineages ( Pseudoroegneria / Lophopyrum  +  Thinopyrum / Dasypyrum ) being suffered from a chloroplast capture event prior to polyploidization events. Analyses of diversification rates detected a significant acceleration approximately five million years ago in the St -genome-sharing taxa. Molecular tests of evolution and gene expression further indicated that radiation within the accelerated group has been accompanied by adaptive genetic changes in a few chloroplast-encoded genes directly or indirectly related to photosynthesis. Conclusions Our results support an important role for adaptive evolution in plastomes during accelerated diversification. In combination with plastome data, further investigations using other genomes, such as the nuclear genome, are urgently needed to enhance our understanding of the evolutionary history of the St -genome-sharing taxa, especially to determine whether adaptive changes in the nuclear genome are accelerated as well because plastome represents the maternal inheritation in angiosperms.

Phylogenetic origin of the Y haplome present in allopolyploid Triticeae species remains unknown. Here, we report the 10.47 Gb chromosome-scale genome of allohexaploid Elymus nutans (StStYYHH). Phylogenomic analyses reveal that the Y haplome is sister to the clade comprising V and Jv haplomes from Dasypyrum and Thinopyum . In addition, H haplome from the Hordeum -like ancestor, St haplome from the Pseudoroegneria -like ancestor and Y haplome are placed in the successively diverged clades. Resequencing data reveal the allopolyploid origins with St, Y, and H haplome combinations in Elymus . Population genomic analyses indicate that E. nutans has expanded from medium to high/low-altitude regions. Phenotype/environmental association analyses identify MAPKKK18 promoter mutations reducing its expression, aiding UV-B adaptation in high-altitude populations. These findings enhance understanding of allopolyploid evolution and aid in breeding forage and cereal crops through intergeneric hybridization within Triticeae. Phylogenetic origin of the Y haplome present in allopolyploid Triticeae species is unclear. Here, the authors report the genome assembly of allohexaploid Elymus nutans , reveal the all likely combinations of St, Y, and H haplomes during the allopolyploid origins, and identify gene responsible for UV-B radiation adaptation.

Background Elymus breviaristatus and Elymus sinosubmuticus are perennial herbs, not only morphologically similar but also sympatric distribution. The genome composition of E. sinosubmuticus has not been reported, and the relationship between E. sinosubmuticus and E. breviaristatus is still controversial. We performed artificial hybridization, genomic in situ hybridization, and phylogenetic analyses to clarify whether the two taxa were the same species. Results The high frequency bivalent (with an average of 20.62 bivalents per cell) at metaphase I of pollen mother cells of the artificial hybrids of E. breviaristatus ( StYH ) ×  E. sinosubmuticus was observed. It illustrated that E. sinosubmuticus was closely related to E. breviaristatus . Based on genomic in situ hybridization results, we confirmed that E. sinosubmuticus was an allohexaploid, and the genomic constitution was StYH . Phylogenetic analysis results also supported that this species contained St , Y , and H genomes. In their F 1 hybrids, pollen activity was 53.90%, and the seed setting rate was 22.46%. Those indicated that the relationship between E. sinosubmuticus and E. breviaristatus is intersubspecific rather than interspecific, and it is reasonable to treated E. sinosubmuticus as the subspecies of E. breviaristatus . Conclusions In all, the genomic constitutions of E. sinosubmuticus and E. breviaristatus were StYH , and they are species in the genus Campeiostachys. Because E. breviaristatus was treated as Campeistachys breviaristata , Elymus sinosubmuticus should be renamed Campeiostachys breviaristata (Keng) Y. H. Zhou, H. Q. Zhang et C. R. Yang subsp. sinosubmuticus (S. L. Chen) Y. H. Zhou, H. Q. Zhang et L. Tan.

To investigate the pattern of chloroplast genome variation in Triticeae, we comprehensively analyzed the indels in protein-coding genes and intergenic sequence, gene loss/pseudonization, intron variation, expansion/contraction in inverted repeat regions, and the relationship between sequence characteristics and chloroplast genome size in 34 monogenomic Triticeae plants. Ancestral genome reconstruction suggests that major length variations occurred in four-stem branches of monogenomic Triticeae followed by independent changes in each genus. It was shown that the chloroplast genome sizes of monogenomic Triticeae were highly variable. The chloroplast genome of Pseudoroegneria , Dasypyrum , Lophopyrum , Thinopyrum , Eremopyrum , Agropyron , Australopyrum , and Henradia in Triticeae had evolved toward size reduction largely because of pseudogenes elimination events and length deletion fragments in intergenic. The Aegilops / Triticum complex, Taeniatherum , Secale , Crithopsis , Herteranthelium , and Hordeum in Triticeae had a larger chloroplast genome size. The large size variation in major lineages and their subclades are most likely consequences of adaptive processes since these variations were significantly correlated with divergence time and historical climatic changes. We also found that several intergenic regions, such as pet N– trn C and psb E– pet L containing unique genetic information, which can be used as important tools to identify the maternal relationship among Triticeae species. Our results contribute to the novel knowledge of plastid genome evolution in Triticeae.

Objective. This study aimed to explore the early diagnosis of abnormal left ventricular systolic function of rare pathogenic titin (TTN) mutation gene carriers in familial hypertrophic cardiomyopathy (FHCM) by three-dimensional speckle tracking echocardiography (3D-STE) combined with gene detection. Methods. Eighteen members of a Hui nationality family in Ningxia province of China were enrolled in this study in July 2019. The proband was tested with high-throughput sequencing of gene detection technology to detect the whole exome, and the mutation locus of pathogenic TTN gene was analyzed. According to the result, 16 subjects were divided into two groups: carrier group (n = 4) and noncarrier group (n = 12). Related indicators from 2DE were obtained, and myocardial strain indicators from 3D-STE were analyzed by postprocessing software of Tomtec. Strain indicators included global longitudinal strain (GLS), global circumference strain (GCS), global radial strain (GRS), regional longitudinal strain (RLS), regional circumference strain (RCS), and regional radial strain (RRS). All those indicators were compared between the two groups, and a receiver operating characteristic (ROC) curve was used for further analysis. Results. There were 4 subjects diagnosed as asymptomatic TTN gene carriers with the mutation locus of Val135643Ile. Compared with the noncarrier group, GLS and partial RLS were significantly reduced in the carrier group. The ROC curve shows that GLS has the largest AUC, and its sensitivity was better than LVPWD and specificity was better than IVSD and LVMI obtained from 2DE in the carrier group. Conclusions. There were 4 subjects diagnosed as asymptomatic TTN gene carriers with the mutation locus of Val135643Ile, and their GLS and partial RLS were significantly reduced; GLS had the better sensitivity and specificity than LVPWD, IVSD, and LVMI.

Disentangling the phylogenetic relationship of polyploid species is essential for understanding how such polyploid species evolved following their origin. To investigate the speciation and evolutionary history of Eremopyrum, we analyzed 36 transcriptomes from 9 polyploid accessions of Eremopyrum and 27 diploid taxa representing 12 basic genomes in Triticeae. Phylogenetic reconstruction, divergence time, and introgression event demonstrated that (1) Eremopyrum and Agropyron shared a common ancestor; (2) Eremopyrum has undergone ongoing evolutionary diversification since its origin in Late Miocene; (3) the diploid E. triticeum and E. distans were the genome donors of the tetraploid species of Eremopyrum; (4) both Eremopyrum and Agropyron contribute to the nonmonophyletic origin of tetraploid E. orientale via introgression events. Our results shed new light on our understanding of the diversity and ecological adaptation of the species in Eremopyrum. Disentangling the phylogenetic relationship of polyploid species is essential for understanding how such polyploid species evolved following their origin. To investigate the speciation and evolutionary history of Eremopyrum, we analyzed 36 transcriptomes from 9 polyploid accessions of Eremopyrum and 27 diploid taxa representing 12 basic genomes in Triticeae. Our results shed new light on our understanding of diversity and ecological adaptation of the species in Eremopyrum.

Background and aims – Campeiostachys is an allohexaploid perennial genus of the Triticeae tribe (Poaceae). The allopolyploids of Triticeae are produced by interspecific hybridization of different genera. In this study, we investigate the genome origin of Campeiostachys and the relationships of some species based on phylogenetic analyses. Material and methods – Two nuclear ( Acc1 and DMC1 ) and two chloroplast ( matK and rps16 ) DNA regions of the species of Campeiostachys and its related genera were used for phylogenetic analyses. Key results – The Acc1 and DMC1 sequences revealed that the genome composition of all Campeiostachys species in our study is StYH , suggesting that Campeiostachys may have originated by the natural hybridization between species with StY and H genomes, as no species with Y or HY genomes have been found in the wild. The results from the chloroplast regions indicated that the maternal donor of the Campeiostachys species contains the St subgenome. In addition, phylogenetic analysis of the nuclear sequences showed that C. purpuraristata always groups with the species of the C. dahurica complex in the St , Y , or H clade, distinct from other species in the genus. Also, C. calcicola , C. kamoji , and C. tsukushiensis var. transiens are distinct yet closely related species. Conclusion – Campeiostachys species originated from the natural hybridization of the tetraploid species of Roegneria ( StY ) with the diploid species of Hordeum ( H ), with Roegneria ( StY ) acting as the maternal donor. Campeiostachys purpuraristata should be classified into the C. dahurica complex and treated as C. dahurica var. purpuraristata.

Background Elymus atratus (Nevski) Hand.-Mazz. is perennial hexaploid wheatgrass. It was assigned to the genus Elymus L. sensu stricto based on morphological characters. Its genome constitution has not been disentangled yet. Objective To identify the genome constitution and origin of E. atratus . Methods In this study, genomic in situ hybridization and fluorescence in situ hybridization, and phylogenetic analysis based on the Acc1, DMC1 and matK sequences were performed. Results Genomic in situ hybridization and fluorescence in situ hybridization results reveal that E. atratus 2n = 6x = 42 is composed of 14 St genome chromosomes, 14 H genome chromosomes, and 14 Y genome chromosomes including two H - Y type translocation chromosomes, suggesting that the genome formula of E. atratus is StStYYHH . The phylogenetic analysis based on Acc1 and DMC1 sequences not only shows that the Y genome originated in a separate diploid, but also suggests that Pseudoroegneria ( St ), Hordeum ( H ), and a diploid species with Y genome were the potential donors of E. atratus . Data from chloroplast DNA showed that the maternal donor of E. atratus contains the St genome. Conclusion Elymus atratus is an allohexaploid species with StYH genome, which may have originated through the hybridization between an allotetraploid Roegneria ( StY ) species as the maternal donor and a diploid Hordeum ( H ) species as the paternal donor.

Background Hybridization and polyploidization can be major mechanisms for plant evolution and speciation. Thus, the process of polyploidization and evolutionary history of polyploids is of widespread interest. The species in Elymus L. sensu lato are allopolyploids that share a common St genome from Pseudoroegneria in different combinations with H, Y, P, and W genomes. But how the St genome evolved in the Elymus s. l. during the hybridization and polyploidization events remains unclear. We used nuclear and chloroplast DNA-based phylogenetic analyses to shed some light on this process. Results The Maximum likelihood (ML) tree based on nuclear ribosomal internal transcribed spacer region (nrITS) data showed that the Pseudoroegneria , Hordeum and Agropyron species served as the St, H and P genome diploid ancestors, respectively, for the Elymus s. l. polyploids. The ML tree for the chloroplast genes ( mat K and the intergenic region of trn H- psb A) suggests that the Pseudoroegneria served as the maternal donor of the St genome for Elymus s. l. Furthermore, it suggested that Pseudoroegneria species from Central Asia and Europe were more ancient than those from North America. The molecular evolution in the St genome appeared to be non-random following the polyploidy event with a departure from the equilibrium neutral model due to a genetic bottleneck caused by recent polyploidization. Conclusion Our results suggest the ancient common maternal ancestral genome in Elymus s. l. is the St genome from Pseudoroegneria . The evolutionary differentiation of the St genome in Elymus s. l. after rise of this group may have multiple causes, including hybridization and polyploidization. They also suggest that E. tangutorum should be treated as C. dahurica var. tangutorum , and E. breviaristatus should be transferred into Campeiostachys . We hypothesized that the Elymus s. l. species origined in Central Asia and Europe, then spread to North America. Further study of intraspecific variation may help us evaluate our phylogenetic results in greater detail and with more certainty.