Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.486
Filtrar
1.
BMC Plant Biol ; 19(1): 332, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31357930

RESUMO

BACKGROUND: Good establishment is important for rapid leaf area development in wheat crops. Poor establishment results in fewer, later-emerging plants, reduced leaf area and tiller number. In addition, poorly established crops suffer from increased soil moisture loss through evaporation and greater competition from weeds while fewer spikes are produced which can reduce grain yield. By protecting the emerging first leaf, the coleoptile is critical for achieving good establishment, and its length and interaction with soil physical properties determine the ability of a cultivar to emerge from depth. RESULTS: Here we characterise a locus on chromosome 1AS, that increases coleoptile length in wheat, which we designate as Lcol-A1. We identified Lcol-A1 by bulked-segregant analysis and used a Halberd-derived population to fine map the gene to a 2 cM region, equivalent to 7 Mb on the IWGSC genome reference sequence of Chinese Spring (RefSeqv1.0). By sowing recently released cultivars and near-isogenic lines in the field at both conventional and deep sowing depths, we confirmed that Locl-A1 was associated with increased emergence from depth in the presence and absence of conventional dwarfing genes. Flanking markers IWB58229 and IWA710 were developed to assist breeders to select for long coleoptile wheats. CONCLUSIONS: Increased coleoptile length is sought in many global wheat production areas to improve crop emergence. The identification of the gene Lcol-A1, together with tools to allow wheat breeders to track the gene, will enable improvements to be made for this important trait.


Assuntos
Cotilédone/crescimento & desenvolvimento , Genes de Plantas/fisiologia , Triticum/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Genes de Plantas/genética , Estudos de Associação Genética , Loci Gênicos , Folhas de Planta/crescimento & desenvolvimento , Polimorfismo de Nucleotídeo Único/genética , Característica Quantitativa Herdável , Triticum/crescimento & desenvolvimento
2.
J Agric Food Chem ; 67(32): 8766-8772, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31313921

RESUMO

In decades of hybrid rice breeding, the combining ability has been successfully used to evaluate excellent parental lines and predict heterosis. However, previous studies for the combining ability mainly focused on cultivated rice and rarely involved wild rice. In this study, for the first time, we identified 20 new quantitative trait loci (QTLs) for the combining ability in wild rice using a North Carolina II mating design. Among them, qGCA1, one of the major QTLs that can significantly improve the general combining ability of the plant height, spikelet number, and yield per plant, was delimited to an interval of about 72 kb on chromosome 1. qSCA8, another major QTL, which can significantly improve the specific combining ability of the seed-setting rate and yield per plant, was located in an interval of about 90 kb on chromosome 8. These QTLs discovered from wild rice will provide new ideas to explain the genetic mechanism of the combining ability and establish the basis for breeding of high-combining-ability rice.


Assuntos
Cromossomos de Plantas/genética , Oryza/genética , Locos de Características Quantitativas , Mapeamento Cromossômico , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Fenótipo , Melhoramento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
3.
BMC Plant Biol ; 19(1): 242, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174465

RESUMO

BACKGROUND: Recurrent drought associated with climate change is a major constraint to wheat (Triticum aestivum L.) productivity. This study aimed to (i) quantify the effects of addition/substitution/translocation of chromosome segments from wild relatives of wheat on the root, physiological and yield traits of hexaploid wheat under drought, and (ii) understand the mechanism(s) associated with drought tolerance or susceptibility in wheat-alien chromosome lines. METHODS: A set of 48 wheat-alien chromosome lines (addition/substitution/translocation lines) with Chinese Spring background were used. Seedling root traits were studied on solid agar medium. To understand the influence of drought on the root system of adult plants, these 48 lines were grown in 150-cm columns for 65 d under full irrigation or withholding water for 58 d. To quantify the effect of drought on physiological and yield traits, the 48 lines were grown in pots under full irrigation until anthesis; after that, half of the plants were drought stressed by withholding water for 16 d before recording physiological and yield-associated traits. RESULTS: The alien chromosome lines exhibited altered root architecture and decreased photochemical efficiency and seed yield and its components under drought. The wheat-alien chromosome lines T5DS·5S#3L (TA5088) with a chromosome segment from Aegilops speltoides (5S) and T5DL.5 V#3S (TA5638) with a chromosome segment from Dasypyrum villosum (5 V) were identified as drought tolerant, and the drought tolerance mechanism was associated with a deep, thin and profuse root system. CONCLUSIONS: The two germplasm lines (TA5088 and TA5638) could be used in wheat breeding programs to improve drought tolerance in wheat and understand the underlying molecular genetic mechanisms of root architecture and drought tolerance.


Assuntos
Cromossomos de Plantas/genética , Secas , Genes de Plantas/genética , Melhoramento Vegetal , Triticum/genética , Aegilops/genética , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Poaceae/genética , Triticum/anatomia & histologia , Triticum/crescimento & desenvolvimento
4.
BMC Plant Biol ; 19(1): 259, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208337

RESUMO

BACKGROUND: Cultivated rice (Oryza sativa L.) is one of the staple food for over half of the world's population. Thus, improvement of cultivated rice is important for the development of the world. It has been shown that abundant elite genes exist in rice landraces in previous studies. RESULTS: A genome-wide association study (GWAS) performed with EMMAX for 12 agronomic traits measured in both Guangzhou and Hangzhou was carried out using 150 accessions of Ting's core collection selected based on 48 phenotypic traits from 2262 accessions of Ting's collection, the GWAS included more than 3.8 million SNPs. Within Ting's core collection, which has a simple population structure, low relatedness, and rapid linkage disequilibrium (LD) decay, we found 32 peaks located closely to previously cloned genes such as Hd1, SD1, Ghd7, GW8, and GL7 or mapped QTL, and these loci might be natural variations in the cloned genes or QTL which influence potentially agronomic traits. Furthermore, we also detected 32 regions where new genes might be located, and some peaks of these new candidate genes such as the signal on chromosome 11 for heading days were even higher than that of Hd1. Detailed annotation of these significant loci were shown in this study. Moreover, according to the estimated LD decay distance of 100 to 350 kb on the 12 chromosomes in this study, we found 13 identical significant regions in the two locations. CONCLUSIONS: This research provided important information for further mining these elite genes within Ting's core collection and using them for rice breeding.


Assuntos
Oryza/genética , Característica Quantitativa Herdável , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Genes de Plantas/genética , Estudos de Associação Genética , Estudo de Associação Genômica Ampla , Desequilíbrio de Ligação/genética , Locos de Características Quantitativas/genética
5.
BMC Plant Biol ; 19(1): 226, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31146681

RESUMO

BACKGROUND: Repetitive DNA motifs - not coding genetic information and repeated millions to hundreds of times - make up the majority of many genomes. Here, we identify the nature, abundance and organization of all the repetitive DNA families in oats (Avena sativa, 2n = 6x = 42, AACCDD), a recognized health-food, and its wild relatives. RESULTS: Whole-genome sequencing followed by k-mer and RepeatExplorer graph-based clustering analyses enabled assessment of repetitive DNA composition in common oat and its wild relatives' genomes. Fluorescence in situ hybridization (FISH)-based karyotypes are developed to understand chromosome and repetitive sequence evolution of common oat. We show that some 200 repeated DNA motifs make up 70% of the Avena genome, with less than 20 families making up 20% of the total. Retroelements represent the major component, with Ty3/Gypsy elements representing more than 40% of all the DNA, nearly three times more abundant than Ty1/Copia elements. DNA transposons are about 5% of the total, while tandemly repeated, satellite DNA sequences fit into 55 families and represent about 2% of the genome. The Avena species are monophyletic, but both bioinformatic comparisons of repeats in the different genomes, and in situ hybridization to metaphase chromosomes from the hexaploid species, shows that some repeat families are specific to individual genomes, or the A and D genomes together. Notably, there are terminal regions of many chromosomes showing different repeat families from the rest of the chromosome, suggesting presence of translocations between the genomes. CONCLUSIONS: The relatively small number of repeat families shows there are evolutionary constraints on their nature and amplification, with mechanisms leading to homogenization, while repeat characterization is useful in providing genome markers and to assist with future assemblies of this large genome (c. 4100 Mb in the diploid). The frequency of inter-genomic translocations suggests optimum strategies to exploit genetic variation from diploid oats for improvement of the hexaploid may differ from those used widely in bread wheat.


Assuntos
Avena/genética , DNA de Plantas , Evolução Molecular , Sequências Repetitivas de Ácido Nucleico , Cromossomos de Plantas/genética , Diploide , Genoma de Planta/genética , Hibridização in Situ Fluorescente , Cariotipagem , Poliploidia , Sequenciamento Completo do Genoma
6.
Gene ; 710: 291-306, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31185283

RESUMO

The WD40 transcription factor family is a superfamily found in all eukaryotes that plays important roles in regulating growth and development. To our knowledge, to date, WD40 superfamily genes have been identified and characterized in several plant species, but little information is available on the WD40 superfamily genes in peach. In this study, we identified 220 members of the WD40 superfamily in the peach genome, and these members were further classified into five subfamilies based on phylogenetic comparison with those in Arabidopsis. The members within each subfamily had conserved motifs and gene structures. The WD40 genes were unevenly distributed on chromosomes 1 to 8 of the peach genome. Additionally, 58 pairs of paralog WD40 members were found on eight chromosomes in peach, and 242 pairs of orthologous WD40 genes in peach and Arabidopsis were matched. The 54 selected putative WD40 genes in peach had diverse expression patterns in red-fleshed and white-fleshed peach fruits at five developmental stages. Prupe.6G211800.1 was located only on the cytomembrane, while Prupe.1G428200.1 and Prupe.I003200.1 were located on both the cytomembrane and in the nucleus; Prupe.1G558700.1 was densely localized around the nuclear rim but relatively faintly localized in the nucleoplasm; Prupe.5G116300.1 was located in the nucleus and cytomembrane with strong signals but showed weak signals in the cytoplasm; and Prupe.8G212400.1 and Prupe.1G053600.1 were located mainly in the nuclear envelope and cytomembrane but relatively faintly in the nucleoplasm. This study provides a foundation for the further functional verification of WD40 genes in peach.


Assuntos
Mapeamento Cromossômico/métodos , Família Multigênica , Proteínas de Plantas/genética , Prunus persica/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cromossomos de Plantas/genética , Sequência Conservada , Citoplasma/genética , Citoplasma/metabolismo , Regulação da Expressão Gênica de Plantas , Filogenia , Proteínas de Plantas/metabolismo , Prunus persica/metabolismo , Repetições WD40
7.
BMC Plant Biol ; 19(1): 183, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31060503

RESUMO

BACKGROUND: Triticum timopheevii (2n = 4x = 28; AtAtGG), is an important source for new genetic variation for wheat improvement with genes for potential disease resistance and salt tolerance. By generating a range of interspecific hybrid lines, T. timopheevii can contribute to wheat's narrow gene-pool and be practically utilised in wheat breeding programmes. Previous studies that have generated such introgression lines between wheat and its wild relatives have been unable to use high-throughput methods to detect the presence of wild relative segments in such lines. RESULTS: A whole genome introgression approach, exploiting homoeologous recombination in the absence of the Ph1 locus, has resulted in the transfer of different chromosome segments from both the At and G genomes of T. timopheevii into wheat. These introgressions have been detected and characterised using single nucleotide polymorphism (SNP) markers present on a high-throughput Axiom® Genotyping Array. The analysis of these interspecific hybrid lines has resulted in the detection of 276 putative unique introgressions from T. timopheevii, thereby allowing the generation of a genetic map of T. timopheevii containing 1582 SNP markers, spread across 14 linkage groups representing each of the seven chromosomes of the At and G genomes of T. timopheevii. The genotyping of the hybrid lines was validated through fluorescence in situ hybridisation (FISH). Comparative analysis of the genetic map of T. timopheevii and the physical map of the hexaploid wheat genome showed that synteny between the two species is highly conserved at the macro-level and confirmed the presence of inter- and intra-genomic translocations within the At and G genomes of T. timopheevii that have been previously only detected through cytological techniques. CONCLUSIONS: In this work, we report a set of SNP markers present on a high-throughput genotyping array, able to detect the presence of T. timopheevii in a hexaploid wheat background making it a potentially valuable tool for marker assisted selection (MAS) in wheat pre-breeding programs. These valuable resources of high-density molecular markers and wheat-T. timopheevii hybrid lines will greatly enhance the work being undertaken for wheat improvement through wild relative introgressions.


Assuntos
Genoma de Planta , Hibridização Genética , Poliploidia , Triticum/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Cruzamentos Genéticos , Ecótipo , Ligação Genética , Loci Gênicos , Marcadores Genéticos , Genótipo , Polimorfismo de Nucleotídeo Único/genética , Recombinação Genética/genética , Sementes/genética , Especificidade da Espécie
8.
BMC Plant Biol ; 19(1): 191, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31072335

RESUMO

BACKGROUND: BRASSINAZOLE-RESISTANT (BZR) family genes encode plant-specific transcription factors (TFs) that participate in brassinosteroid signal transduction. BZR TFs have vital roles in plant growth, including cell elongation. However, little is known about BZR genes in sugar beet (Beta vulgaris L.). RESULTS: Therefore, we performed a genome-wide investigation of BvBZR genes in sugar beet. Through an analysis of the BES1_N conserved domain, six BvBZR gene family members were identified in the sugar beet genome, which clustered into three subgroups according to a phylogenetic analysis. Each clade was well defined by the conserved motifs, implying that close genetic relationships could be identified among the members of each subfamily. According to chromosomal distribution mapping, 2, 1, 1, 1, and 1 genes were located on chromosomes 1, 4, 5, 6, and 8, respectively. The cis-acting elements related to taproot growth were randomly distributed in the promoter sequences of the BvBZR genes. Tissue-specific expression analyses indicated that all BvBZR genes were expressed in all three major tissue types (roots, stems, and leaves), with significantly higher expression in leaves. Subcellular localization analysis revealed that Bv1_fxre and Bv6_nyuw are localized in the nuclei, consistent with the prediction of Wolf PSORT. CONCLUSION: These findings offer a basis to predict the functions of BZR genes in sugar beet, and lay a foundation for further research of the biological functions of BZR genes in sugar beet.


Assuntos
Beta vulgaris/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Fatores de Transcrição/genética , Motivos de Aminoácidos , Beta vulgaris/efeitos dos fármacos , Cromossomos de Plantas/genética , Sequência Conservada/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Proteínas de Fluorescência Verde/metabolismo , Motivos de Nucleotídeos/genética , Filogenia , Reguladores de Crescimento de Planta/farmacologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo
9.
Nat Genet ; 51(5): 877-884, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31043755

RESUMO

Like many other crops, the cultivated peanut (Arachis hypogaea L.) is of hybrid origin and has a polyploid genome that contains essentially complete sets of chromosomes from two ancestral species. Here we report the genome sequence of peanut and show that after its polyploid origin, the genome has evolved through mobile-element activity, deletions and by the flow of genetic information between corresponding ancestral chromosomes (that is, homeologous recombination). Uniformity of patterns of homeologous recombination at the ends of chromosomes favors a single origin for cultivated peanut and its wild counterpart A. monticola. However, through much of the genome, homeologous recombination has created diversity. Using new polyploid hybrids made from the ancestral species, we show how this can generate phenotypic changes such as spontaneous changes in the color of the flowers. We suggest that diversity generated by these genetic mechanisms helped to favor the domestication of the polyploid A. hypogaea over other diploid Arachis species cultivated by humans.


Assuntos
Arachis/genética , Arachis/classificação , Argentina , Cromossomos de Plantas/genética , Produtos Agrícolas/genética , Metilação de DNA , DNA de Plantas/genética , Domesticação , Evolução Molecular , Regulação da Expressão Gênica de Plantas , Variação Genética , Genoma de Planta , Hibridização Genética , Fenótipo , Poliploidia , Recombinação Genética , Especificidade da Espécie , Tetraploidia
10.
Nat Genet ; 51(5): 865-876, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31043757

RESUMO

High oil and protein content make tetraploid peanut a leading oil and food legume. Here we report a high-quality peanut genome sequence, comprising 2.54 Gb with 20 pseudomolecules and 83,709 protein-coding gene models. We characterize gene functional groups implicated in seed size evolution, seed oil content, disease resistance and symbiotic nitrogen fixation. The peanut B subgenome has more genes and general expression dominance, temporally associated with long-terminal-repeat expansion in the A subgenome that also raises questions about the A-genome progenitor. The polyploid genome provided insights into the evolution of Arachis hypogaea and other legume chromosomes. Resequencing of 52 accessions suggests that independent domestications formed peanut ecotypes. Whereas 0.42-0.47 million years ago (Ma) polyploidy constrained genetic variation, the peanut genome sequence aids mapping and candidate-gene discovery for traits such as seed size and color, foliar disease resistance and others, also providing a cornerstone for functional genomics and peanut improvement.


Assuntos
Arachis/genética , Arachis/embriologia , Arachis/fisiologia , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Resistência à Doença/genética , Domesticação , Secas , Ecótipo , Evolução Molecular , Genoma de Planta , Cariótipo , Óleo de Amendoim/metabolismo , Melhoramento Vegetal , Doenças das Plantas/prevenção & controle , Proteínas de Vegetais Comestíveis/metabolismo , Poliploidia , Sementes/anatomia & histologia , Sementes/genética
11.
Planta ; 250(2): 487-494, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31069521

RESUMO

MAIN CONCLUSION: Contrasting patterns of histone modifications between the X and Y chromosome in Silene latifolia show euchromatic histone mark depletion on the Y chromosome and indicate hyperactivation of one X chromosome in females. Silene latifolia (white campion) is a dioecious plant with heteromorphic sex chromosomes (24, XX in females and 24, XY in males), and a genetically degenerated Y chromosome that is 1.4 times larger than the X chromosome. Although the two sex chromosomes differ in their DNA content, information about epigenetic histone marks and evidence of their function are scarce. We performed immunolabeling experiments using antibodies specific for active and suppressive histone modifications as well as pericentromere-specific histone modifications. We show that the Y chromosome is partially depleted of histone modifications important for transcriptionally active chromatin, and carries these marks only in the pseudo-autosomal region, but that it is not enriched for suppressive and pericentromere histone marks. We also show that two of the active marks are specifically enriched in one of the X chromosomes in females and in the X chromosome in males. Our data support recent findings that genetic imprinting mediates dosage compensation of sex chromosomes in S. latifolia.


Assuntos
Cromossomos de Plantas/genética , Epigênese Genética , Código das Histonas/genética , Silene/genética
12.
BMC Plant Biol ; 19(1): 194, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31077147

RESUMO

BACKGROUND: Our study is the first to provide RNA-Seq data analysis related to transcriptomic responses towards drought across different crops. The aim was to identify and map which genes play a key role in drought response on leaves across different crops. Forty-two RNA-seq samples were analyzed from 9 published studies in 7 plant species (Arabidopsis thaliana, Solanum lycopersicum, Zea mays, Vitis vinifera, Malus X domestica, Solanum tuberosum, Triticum aestivum). RESULTS: Twenty-seven (16 up-regulated and 11 down-regulated) drought-regulated genes were commonly present in at least 7 of 9 studies, while 351 (147 up-regulated and 204 down-regulated) were commonly drought-regulated in 6 of 9 studies. Across all kind of leaves, the drought repressed gene-ontologies were related to the cell wall and membrane re-structuring such as wax biosynthesis, cell wall organization, fatty acid biosynthesis. On the other hand, drought-up-regulated biological processes were related to responses to osmotic stress, abscisic acid, water deprivation, abscisic-activated signalling pathway, salt stress, hydrogen peroxide treatment. A common metabolic feature linked to drought response in leaves is the repression of terpenoid pathways. There was an induction of AL1 (alfin-like), UGKYAH (trihelix), WRKY20, homeobox genes and members of the SET domain family in 6 of 9 studies. Several genes involved in detoxifying and antioxidant reactions, signalling pathways and cell protection were commonly modulated by drought across the 7 species. The chromosome (Chr) mapping of these key abiotic stress genes highlighted that Chr 4 in Arabidopsis thaliana, Chr 1 in Zea mays, Chr 2 and Chr 5 in Triticum aestivum contained a higher presence of drought-related genes compared to the other remaining chromosomes. In seedling studies, it is worth notice the up-regulation of ERF4 and ESE3 (ethylene), HVA22 (abscisic acid), TIR1 (auxin) and some transcription factors (MYB3, MYB94, MYB1, WRKY53 and WRKY20). In mature leaves, ERF1 and Alfin-like 1 were induced by drought while other transcription factors (YABBY5, ARR2, TRFL2) and genes involved phospholipid biosynthesis were repressed. CONCLUSIONS: The identified and mapped genes might be potential targets of molecular breeding activities to develop cultivars with enhanced drought resistance and tolerance across different crops.


Assuntos
Cromossomos de Plantas/genética , Produtos Agrícolas/genética , Genes de Plantas/genética , Folhas de Planta/metabolismo , RNA de Plantas/genética , Arabidopsis/genética , Arabidopsis/fisiologia , Mapeamento Cromossômico , Cromossomos de Plantas/fisiologia , Desidratação , Genes de Plantas/fisiologia , Lycopersicon esculentum/genética , Lycopersicon esculentum/fisiologia , Malus/genética , Malus/fisiologia , Folhas de Planta/anatomia & histologia , RNA de Plantas/fisiologia , Solanum tuberosum/genética , Solanum tuberosum/fisiologia , Triticum/genética , Triticum/fisiologia , Vitis/genética , Vitis/fisiologia , Zea mays/genética , Zea mays/fisiologia
13.
J Plant Res ; 132(4): 461-471, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31115709

RESUMO

Reproductive isolation, including prezygotic and postzygotic barriers, is a mechanism that separates species. Many species in the Nicotiana section Suaveolentes exhibit reproductive isolation in crosses with Nicotiana tabacum. In this study, we investigated whether the chromosome numbers and ploidy levels of eight Nicotiana suaveolens accessions are related to the reproductive isolation after crosses with N. tabacum by flow cytometry and chromosome analyses. Additionally, the internal transcribed spacer (ITS) regions of the eight N. suaveolens accessions were sequenced and compared with the previously reported sequences of 22 Suaveolentes species to elucidate the phylogenetic relationships in the section Suaveolentes. We revealed that four N. suaveolens accessions comprised 64 chromosomes, while the other four accessions carried 32 chromosomes. Depending on the ploidy levels of N. suaveolens, several types of reproductive isolation were observed after crosses with N. tabacum, including decreases in the number of capsules and the germination rates of hybrid seeds, as well as hybrid lethality and abscission of enlarged ovaries at 12-17 days after pollination. A phylogenetic analysis involving ITS sequences divided the eight N. suaveolens accessions into three distinct clades. Based on the results, we confirmed that N. suaveolens accessions vary regarding ploidy levels and reproductive isolation mechanisms in crosses with N. tabacum. These accessions will be very useful for revealing and characterizing the reproductive isolation mechanisms in interspecific crosses and their relationships with ploidy levels.


Assuntos
Ploidias , Isolamento Reprodutivo , Tabaco/genética , Cromossomos de Plantas/genética , Cruzamentos Genéticos , DNA Intergênico/genética , Citometria de Fluxo , Flores/anatomia & histologia , Germinação/genética , Filogenia , Folhas de Planta/anatomia & histologia , Análise de Sequência de DNA , Tabaco/anatomia & histologia , Tabaco/fisiologia
14.
Biomed Res Int ; 2019: 2965035, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31073524

RESUMO

The type 2C protein which belongs to the major group of protein phosphatases (PP2C) plays a vital role in abscisic acid (ABA) signaling and signal transductions processes. In the present study, 131 PP2C genes were identified in total in Brassica rapa and categorized into thirteen subgroups based on their phylogenetic relationships. These B. rapa PP2C are structurally conserved based on amino acid sequence alignment, phylogenetic analysis, and conserved domains. Moreover, we utilized previously reported RNA-sequence data on various tissues (root, stem, leaf, flower, and silique), which suggests overlapping expression pattern in 29 paralogous gene pairs. The qRT-PCR validation of 15 paralogous gene pairs depicts distinct expression patterns in response to various abiotic stresses, such as heat, cold, ABA, and drought. Interestingly, stress-responsive BraPP2C candidate genes were also identified, suggesting their significance in stress-tolerance mechanism in B. rapa. The evolutionary analysis for 15 paralogous gene pairs suggested that only three pairs have the positive selection and remaining were purifying in nature. The presented results of this study hasten our understanding of the molecular evolution of the PP2C gene family in B. rapa. Thus, it will be ultimately helping in future research for facilitating the functional characterization of BraPP2C genes in developing the abiotic stress tolerant plants.


Assuntos
Brassica rapa/genética , Evolução Molecular , Filogenia , Proteína Fosfatase 2C/genética , Sequência de Aminoácidos/genética , Cromossomos de Plantas/genética , Flores/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta/genética , Família Multigênica/genética , Proteína Fosfatase 2C/classificação
15.
BMC Genomics ; 20(1): 367, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088367

RESUMO

BACKGROUND: Species of the Festuca and Lolium genera, as well as intergeneric Festuca × Lolium (Festulolium) hybrids, are valuable fodder and turf grasses for agricultural and amenity purposes worldwide. Festulolium hybrids can merge in their genomes agronomically important characteristics. However, in polyploid plants, especially in allopolyploids, the hybridization of divergent genomes could contribute to various abnormalities, such as variability in chromosome number, structural rearrangements, and/or disorders in inheritance patterns. Here we studied these issues in allotetraploid Festuca pratensis × Lolium perenne hybrids. RESULTS: Cytogenetic procedures, including fluorescent in situ hybridization, genomic in situ hybridization, and molecular markers - inter-simple sequence repeats (ISSR) were exploited. This cytogenetic approach indicated the dynamics in the number and distribution of ribosomal RNA genes and structural rearrangements for both parental genomes (Festuca and Lolium) in hybrid karyotypes. The separate analysis of F. pratensis and L. perenne chromosomes in hybrid plants (F2-F3 generations of F. pratensis × L. perenne) revealed the asymmetrical level of rearrangements. Recognized structural changes were mainly located in the distal part of chromosome arms, and in chromosomes bearing ribosomal DNA, they were more frequently mapped in arms without this sequence. Based on the ISSR markers distribution, we found that the tetrasomic type of inheritance was characteristic for the majority of ISSR loci, but the disomic type was also observed. Nonetheless, no preference in the transmission of either Festuca or Lolium alleles to the following generations of allotetraploid F. pratensis × L. perenne hybrid was observed. CONCLUSION: Our study reports cytogenetic and molecular genotyping of the F. pratensis × L. perenne hybrid and its following F2-F3 progenies. The analysis of 137 allotetraploid F. pratensis × L. perenne hybrids revealed the higher level of recombination in chromosomes derived from F. pratensis genome. The results of ISSR markers indicated a mixed model of inheritance, which may be characteristic for these hybrids.


Assuntos
Quimera/genética , Festuca/genética , Técnicas de Genotipagem/métodos , Lolium/genética , Cromossomos de Plantas/genética , Análise Citogenética , DNA Ribossômico/genética , Variação Genética , Hibridização Genética , Hibridização in Situ Fluorescente , Cariótipo , Repetições de Microssatélites , Tetraploidia
16.
Plant Sci ; 283: 135-146, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128683

RESUMO

The genetic basis of domestication and improvement remains largely unknown in sorghum as a typical multiple-origins species. In this study, the F2 and F3 populations derived from a cross between Sorghum virgatum and domesticated sorghum were used to study the genetic architecture of domestication- and improvement-related traits. We found that human selection had greatly reshaped sorghum through the Quantitative Trait Loci (QTLs) with large genetic effects in the traits of harvest, plant architecture and grain taste including the reduction of shattering, few branches, short plant stature and the removal of polyphenols from seed. The expansion of seed width was selected to improve the yield through accumulating small-effect QTLs. Two major QTLs of plant height (QTI-ph1 and dw1) were narrowed down into 24.5-kilobase (kb) and 13.9-kb, respectively. DNA diversity analysis and association mapping of dw1 gene suggested the functional variant (A1361 T) might originate from the same event not long time ago. Our results supported that parallel phenotypic changes across different species during domestication and improvement might share the same genetic basis, QTL × QTL interactions might not play an important role in the reshaping of traits during sorghum domestication and improvement, and offered new views on transgressive segregation and segregation distortion. Our study greatly deepens our understandings of the genetic basis of sorghum domestication and improvement.


Assuntos
Domesticação , Característica Quantitativa Herdável , Sorghum/genética , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Genes de Plantas/genética , Genoma de Planta/genética , Melhoramento Vegetal/métodos , Locos de Características Quantitativas/genética , Sementes , Sorghum/anatomia & histologia
17.
Plant Sci ; 283: 83-94, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128718

RESUMO

The continuing growth of the human population creates an inevitable necessity for higher crop yields, which are mandatory for the supply with adequate amounts of food. However, increasing grain yield may lead to a reduction of grain quality, such as a decline in protein and mineral nutrient concentrations causing the so-called hidden hunger. To assess the interdependence between quantity and quality and to evaluate the biofortification potential of wild barley, we conducted field studies, examining the interplay between plant development, yield, and nutrient concentrations, using HEB-YIELD, a subset of the wild barley nested association mapping population HEB-25. A huge variation of nutrient concentration in grains was obtained, since we identified lines with a more than 50% higher grain protein, iron, and zinc concentration in comparison to the recurrent parent 'Barke'. We observed a negative relationship between grain yield and nutritional value in barley, indicated by predominantly negative correlations between yield and nutrient concentrations. Analyzing the genetic control of nutrient concentration in mature grains indicated that numerous genomic regions determine the final nutritional value of grains and wild alleles were frequently associated with higher nutrient concentrations. The targeted introgression of wild barley alleles may enable biofortification in future barley breeding.


Assuntos
Biofortificação , Grão Comestível/metabolismo , Hordeum/metabolismo , Biofortificação/métodos , Cromossomos de Plantas/genética , Estudos de Associação Genética , Marcadores Genéticos , Hordeum/genética , Valor Nutritivo , Locos de Características Quantitativas
18.
BMC Plant Biol ; 19(1): 147, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30991940

RESUMO

BACKGROUND: Stripe rust (also called yellow rust) is a common and serious fungal disease of wheat (Triticum aestivum L.) caused by Puccinia striiformis f. sp. tritici. The narrow genetic basis of modern wheat cultivars and rapid evolution of the rust pathogen have been responsible for periodic and devastating epidemics of wheat rust diseases. In this study, we conducted a genome-wide association study with 44,059 single nucleotide polymorphism markers to identify loci associated with resistance to stripe rust in 244 Sichuan wheat accessions, including 79 landraces and 165 cultivars, in six environments. RESULTS: In all the field assessments, 24 accessions displayed stable high resistance to stripe rust. Significant correlations among environments were observed for both infection (IT) and disease severity (DS), and high heritability levels were found for both IT and DS. Using mixed linear models, 12 quantitative trait loci (QTLs) significantly associated with IT and/or DS were identified. Two QTLs were mapped on chromosomes 5AS and 5AL and were distant from previously identified stripe rust resistance genes or QTL regions, indicating that they may be novel resistance loci. CONCLUSIONS: Our results revealed that resistance alleles to stripe rust were accumulated in Sichuan wheat germplasm, implying direct or indirect selection for improved stripe rust resistance in elite wheat breeding programs. The identified stable QTLs or favorable alleles could be important chromosome regions in Sichuan wheat that controlled the resistance to stripe rust. These markers can be used molecular marker-assisted breeding of Sichuan wheat cultivars, and will be useful in the ongoing effort to develop new wheat cultivars with strong resistance to stripe rust.


Assuntos
Basidiomycota/fisiologia , Resistência à Doença/genética , Genoma de Planta , Estudo de Associação Genômica Ampla , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Triticum/genética , Triticum/microbiologia , Alelos , Basidiomycota/patogenicidade , Cromossomos de Plantas/genética , Ecótipo , Loci Gênicos , Variação Genética , Desequilíbrio de Ligação/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Triticum/imunologia , Virulência/genética
19.
BMC Plant Biol ; 19(1): 153, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31014249

RESUMO

BACKGROUND: Fusarium crown rot (FCR) is a severe and chronic disease in common wheat and is able to cause serious yield loss and health problems to human and livestock. RESULTS: Here, 234 Chinese wheat cultivars were evaluated in four greenhouse experiments for FCR resistance and genome-wide association studies (GWAS) were performed using the wheat 660 K genotyping assay. The results indicated that most cultivars evaluated showed FCR disease index (DI) of 40-60, while some cultivars showed stably good FCR resistance (DI < 30). GWAS identified 286 SNPs to be significantly associated with FCR resistance, of which 266, 6 and 8 were distributed on chromosomes 6A, 6B and 6D, respectively. The significant SNPs on 6A were located in a 7.0-Mb region containing 51 annotated genes. On the other hand, QTL mapping using a bi-parental population derived from UC1110 and PI610750 detected three QTLs on chromosomes 6A (explaining 7.77-10.17% of phenotypic variation), 2D (7.15-9.29%) and 2A (5.24-6.92%). The 6A QTL in the UC1110/PI610750 population falls into the same chromosomal region as those detected from GWAS, demonstrating its importance in Chinese materials for FCR resistance. CONCLUSION: This study could provide useful information for utilization of FCR-resistant wheat germplasm and further understanding of molecular and genetics basis of FCR resistance in common wheat.


Assuntos
Resistência à Doença/genética , Fusarium/fisiologia , Genoma de Planta , Estudo de Associação Genômica Ampla , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Triticum/genética , Triticum/microbiologia , Alelos , Cromossomos de Plantas/genética , Haplótipos/genética , Endogamia , Escore Lod , Fenótipo , Doenças das Plantas/imunologia , Polimorfismo de Nucleotídeo Único/genética , Análise de Componente Principal , Locos de Características Quantitativas/genética , Triticum/imunologia
20.
BMC Plant Biol ; 19(1): 157, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31023214

RESUMO

BACKGROUND: Pedicel orientation can affect the female flower orientation and seed yield in cucumber. A spontaneous mutant possessing upward growth of pedicels was identified in the wild type inbred strain 9930 and named upward-pedicel (up). The morphological and genetic analyses of up were performed in this study. In order to clone the up gene, 933 F2 individuals and 524 BC1 individuals derived from C-8-6 (WT) and up were used for map-based cloning. RESULTS: up was mapped to a 35.2 kb physical interval on chromosome 1, which contains three predicted genes. Sequencing analysis revealed that a 5-bp deletion was found in the second exon of Csa1G535800, and it led to a frameshift mutation resulting in a premature stop codon. The candidate gene of CsUp (Csa1G535800) was further confirmed via genomic and cDNA sequencing in biparental and natural cucumber populations. Sequencing data showed that a 4-bp deletion was found in the sixth exon of Csa1G535800 in CGN19839, another inbred line, and there was also a mutation of an amino acid in Csa1G535800 that could contribute to the upward growth of pedicels in CGN19839. Moreover, it was found that Csa1G535800 exhibited strong expression in the pedicel of WT, suggesting its important role in development of pedicel orientation. Thus, Csa1G535800 was considered to be the candidate gene of CsUp. CONCLUSIONS: CsUp encodes an Auxilin-like protein and controls pedicel orientation in cucumber. The identification of CsUp may help us to understand the mechanism of pedicel orientation development and allow for investigation of novel functions of Auxilin-like proteins in cucumber.


Assuntos
Auxilinas/genética , Mapeamento Cromossômico , Cucumis sativus/genética , Genes de Plantas , Estudos de Associação Genética , Mutação/genética , Sequência de Aminoácidos , Sequência de Bases , Segregação de Cromossomos , Cromossomos de Plantas/genética , Cruzamentos Genéticos , Regulação da Expressão Gênica de Plantas , Genes Recessivos , Loci Gênicos , Fenótipo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Característica Quantitativa Herdável , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA