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1.
BMC Genomics ; 23(1): 154, 2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35193500

RESUMO

BACKGROUND: Plant miRNAs are a class of small non-coding RNAs that can repress gene expression at the post-transcriptional level by targeting RNA degradation or promoting translational repression. There is increasing evidence that some miRNAs can derive from a group of non-autonomous class II transposable elements called Miniature Inverted-repeat Transposable Elements (MITEs). RESULTS: We used public small RNA and degradome libraries from Triticum aestivum to screen for microRNAs production and predict their cleavage target sites. In parallel, we also created a comprehensive wheat MITE database by identifying novel elements and compiling known ones. When comparing both data sets, we found high homology between MITEs and 14% of all the miRNAs production sites detected. Furthermore, we show that MITE-derived miRNAs have preference for targeting degradation sites with MITE insertions in the 3' UTR regions of the transcripts. CONCLUSIONS: Our results revealed that MITE-derived miRNAs can underlay the origin of some miRNAs and potentially shape a regulatory gene network. Since MITEs are found in millions of insertions in the wheat genome and are closely linked to genic regions, this kind of regulatory network could have a significant impact on the post-transcriptional control of gene expression.


Assuntos
Elementos de DNA Transponíveis , MicroRNAs , Triticum , Elementos de DNA Transponíveis/genética , Genoma de Planta , Sequências Repetidas Invertidas , MicroRNAs/genética , Triticum/genética
2.
BMC Plant Biol ; 19(1): 553, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31842779

RESUMO

BACKGROUND: Increasing wheat (Triticum aestivum L.) production is required to feed a growing human population. In order to accomplish this task a deeper understanding of the genetic structure of cultivated wheats and the detection of genomic regions significantly associated with the regulation of important agronomic traits are necessary steps. To better understand the genetic basis and relationships of adaptation and yield related traits, we used a collection of 102 Argentinean hexaploid wheat cultivars genotyped with the 35k SNPs array, grown from two to six years in three different locations. Based on SNPs data and gene-related molecular markers, we performed a haplotype block characterization of the germplasm and a genome-wide association study (GWAS). RESULTS: The genetic structure of the collection revealed four subpopulations, reflecting the origin of the germplasm used by the main breeding programs in Argentina. The haplotype block characterization showed 1268 blocks of different sizes spread along the genome, including highly conserved regions like the 1BS chromosome arm where the 1BL/1RS wheat/rye translocation is located. Based on GWAS we identified ninety-seven chromosome regions associated with heading date, plant height, thousand grain weight, grain number per spike and fruiting efficiency at harvest (FEh). In particular FEh stands out as a promising trait to raise yield potential in Argentinean wheats; we detected fifteen haplotypes/markers associated with increased FEh values, eleven of which showed significant effects in all three evaluated locations. In the case of adaptation, the Ppd-D1 gene is consolidated as the main determinant of the life cycle of Argentinean wheat cultivars. CONCLUSION: This work reveals the genetic structure of the Argentinean hexaploid wheat germplasm using a wide set of molecular markers anchored to the Ref Seq v1.0. Additionally GWAS detects chromosomal regions (haplotypes) associated with important yield and adaptation components that will allow improvement of these traits through marker-assisted selection.


Assuntos
Haplótipos , Poliploidia , Triticum/genética , Adaptação Biológica , Argentina , Estudo de Associação Genômica Ampla
3.
BMC Bioinformatics ; 19(1): 348, 2018 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-30285604

RESUMO

BACKGROUND: Miniature inverted-repeat transposable elements (MITEs) are short, non-autonomous class II transposable elements present in a high number of conserved copies in eukaryote genomes. An accurate identification of these elements can help to shed light on the mechanisms controlling genome evolution and gene regulation. The structure and distribution of these elements are well-defined and therefore computational approaches can be used to identify MITEs sequences. RESULTS: Here we describe MITE Tracker, a novel, open source software program that finds and classifies MITEs using an efficient alignment strategy to retrieve nearby inverted-repeat sequences from large genomes. This program groups them into high sequence homology families using a fast clustering algorithm and finally filters only those elements that were likely transposed from different genomic locations because of their low scoring flanking sequence alignment. CONCLUSIONS: Many programs have been proposed to find MITEs hidden in genomes. However, none of them are able to process large-scale genomes such as that of bread wheat. Furthermore, in many cases the existing methods perform high false-positive rates (or miss rates). The rice genome was used as reference to compare MITE Tracker against known tools. Our method turned out to be the most reliable in our tests. Indeed, it revealed more known elements, presented the lowest false-positive number and was the only program able to run with the bread wheat genome as input. In wheat, MITE Tracker discovered 6013 MITE families and allowed the first structural exploration of MITEs in the complete bread wheat genome.


Assuntos
Elementos de DNA Transponíveis/genética , Genômica/métodos , Sequências Repetidas Invertidas/genética , Oryza/genética , Software
4.
Theor Appl Genet ; 131(10): 2021-2035, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29959472

RESUMO

KEY MESSAGE: This study identified Rht25, a new plant height locus on wheat chromosome arm 6AS, and characterized its pleiotropic effects on important agronomic traits. Understanding genes regulating wheat plant height is important to optimize harvest index and maximize grain yield. In modern wheat varieties grown under high-input conditions, the gibberellin-insensitive semi-dwarfing alleles Rht-B1b and Rht-D1b have been used extensively to confer lodging tolerance and improve harvest index. However, negative pleiotropic effects of these alleles (e.g., poor seedling emergence and reduced biomass) can cause yield losses in hot and dry environments. As part of current efforts to diversify the dwarfing alleles used in wheat breeding, we identified a quantitative trait locus (QHt.ucw-6AS) affecting plant height in the proximal region of chromosome arm 6AS (< 0.4 cM from the centromere). Using a large segregating population (~ 2800 gametes) and extensive progeny tests (70-93 plants per recombinant family), we mapped QHt.ucw-6AS as a Mendelian locus to a 0.2 cM interval (144.0-148.3 Mb, IWGSC Ref Seq v1.0) and show that it is different from Rht18. QHt.ucw-6AS is officially designated as Rht25, with Rht25a representing the height-increasing allele and Rht25b the dwarfing allele. The average dwarfing effect of Rht25b was found to be approximately half of the effect observed for Rht-B1b and Rht-D1b, and the effect is greater in the presence of the height-increasing Rht-B1a and Rht-D1a alleles than in the presence of the dwarfing alleles. Rht25b is gibberellin-sensitive and shows significant pleiotropic effects on coleoptile length, heading date, spike length, spikelet number, spikelet density, and grain weight. Rht25 represents a new alternative dwarfing locus that should be evaluated for its potential to improve wheat yield in different environments.


Assuntos
Genes de Plantas , Locos de Características Quantitativas , Triticum/crescimento & desenvolvimento , Triticum/genética , Alelos , Mapeamento Cromossômico , Cromossomos de Plantas , Cruzamentos Genéticos , Pleiotropia Genética , Genótipo , Giberelinas/farmacologia , Fenótipo , Melhoramento Vegetal
5.
BMC Genomics ; 16: 375, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25962417

RESUMO

BACKGROUND: The number and complexity of repetitive elements varies between species, being in general most represented in those with larger genomes. Combining the flow-sorted chromosome arms approach to genome analysis with second generation DNA sequencing technologies provides a unique opportunity to study the repetitive portion of each chromosome, enabling comparisons among them. Additionally, different sequencing approaches may produce different depth of insight to repeatome content and structure. In this work we analyze and characterize the repetitive sequences of Triticum aestivum cv. Chinese Spring homeologous group 4 chromosome arms, obtained through Roche 454 and Illumina sequencing technologies, hereinafter marked by subscripts 454 and I, respectively. Repetitive sequences were identified with the RepeatMasker software using the interspersed repeat database mips-REdat_v9.0p. The input sequences consisted of our 4DS454 and 4DL454 scaffolds and 4ASI, 4ALI, 4BSI, 4BLI, 4DSI and 4DLI contigs, downloaded from the International Wheat Genome Sequencing Consortium (IWGSC). RESULTS: Repetitive sequences content varied from 55% to 63% for all chromosome arm assemblies except for 4DLI, in which the repeat content was 38%. Transposable elements, small RNA, satellites, simple repeats and low complexity sequences were analyzed. SSR frequency was found one per 24 to 27 kb for all chromosome assemblies except 4DLI, where it was three times higher. Dinucleotides and trinucleotides were the most abundant SSR repeat units. (GA)n/(TC)n was the most abundant SSR except for 4DLI where the most frequently identified SSR was (CCG/CGG)n. Retrotransposons followed by DNA transposons were the most highly represented sequence repeats, mainly composed of CACTA/En-Spm and Gypsy superfamilies, respectively. This whole chromosome sequence analysis allowed identification of three new LTR retrotransposon families belonging to the Copia superfamily, one belonging to the Gypsy superfamily and two TRIM retrotransposon families. Their physical distribution in wheat genome was analyzed by fluorescent in situ hybridization (FISH) and one of them, the Carmen retrotransposon, was found specific for centromeric regions of all wheat chromosomes. CONCLUSION: The presented work is the first deep report of wheat repetitive sequences analyzed at the chromosome arm level, revealing the first insight into the repeatome of T. aestivum chromosomes of homeologous group 4.


Assuntos
DNA de Plantas/análise , Sequências Repetitivas de Ácido Nucleico , Triticum/genética , Cromossomos de Plantas/genética , Mapeamento Físico do Cromossomo , Análise de Sequência de DNA/métodos
6.
Heliyon ; 10(11): e32383, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38933970

RESUMO

Lactococcus garviae (L. garviae) is a gram-positive coccus belonging to the Streptococcaceae family. While primarily a pathogen in fish farms causing hemorrhagic sepsis, it can act as a rare opportunistic pathogen in humans. A 2021 case report by Bravo et al. documented less than 30 cases of infective endocarditis caused by L. garviae worldwide at that time [1]. This case report describes the 27th documented case globally and 7th documented case in the USA of L. garviae causing infective endocarditis of a prosthetic valve [1]. L. garviae is found in unpasteurized dairy products, raw fish, and meat (pork, beef, and poultry), but the route of human transmission remains unclear [3]. It seems to have a predilection for individuals with prosthetic valves, immunocompromised states, prior gastrointestinal surgery, gastrointestinal disorders (colon polyps and diverticulosis), and the use of acid-reducing medications [1-3]. Infective endocarditis is the most common systemic disease caused by L. garviae [1-4]. This report details the case of a 75-year-old male, with multiple comorbidities and risk factors for L. garviae infection who was admitted for "symptomatic anemia". High clinical suspicion, coupled with an inadequate hemoglobin response to transfusion, a normal anemia workup, and blood cultures positive for L. garviae, promoted a transesophageal echocardiogram (TEE). However, the results were negative. Consequently, an 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan (18FDG PET/CT) was performed. The scan revealed increased uptake in the aortic valve replacement consistent with prosthetic valve endocarditis in the setting of Lactococcus garviae bacteremia.

7.
Genet Mol Biol ; 36(3): 391-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24130447

RESUMO

The identification of genetically homogeneous groups of individuals is an ancient issue in population genetics and in the case of crops like wheat, it can be valuable information for breeding programs, genetic mapping and germplasm resources. In this work we determined the genetic structure of a set of 102 Argentinean bread wheat (Triticum aestivum L.) elite cultivars using 38 biochemical and molecular markers (functional, closely linked to genes and neutral ones) distributed throughout 18 wheat chromosomes. Genetic relationships among these lines were examined using model-based clustering methods. In the analysis three subpopulations were identified which correspond largely to the origin of the germplasm used by the main breeding programs in Argentina.

8.
Nat Commun ; 13(1): 4315, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35882860

RESUMO

The fungus Blumeria graminis f. sp. tritici causes wheat powdery mildew disease. Here, we study its spread and evolution by analyzing a global sample of 172 mildew genomes. Our analyses show that B.g. tritici emerged in the Fertile Crescent during wheat domestication. After it spread throughout Eurasia, colonization brought it to America, where it hybridized with unknown grass mildew species. Recent trade brought USA strains to Japan, and European strains to China. In both places, they hybridized with local ancestral strains. Thus, although mildew spreads by wind regionally, our results indicate that humans drove its global spread throughout history and that mildew rapidly evolved through hybridization.


Assuntos
Doenças das Plantas , Triticum , Genômica , Migração Humana , Humanos , Doenças das Plantas/microbiologia , Poaceae , Triticum/genética , Triticum/microbiologia
9.
Methods Mol Biol ; 2072: 27-37, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31541436

RESUMO

Next generation sequencing (NGS) and assembly are key pieces in the success of cereal crops genomes sequencing. One interesting strategy for reducing the complexity in large genomes, the case of several cereal crops, is the sequencing of individual chromosomes. This has been done with success by flow cytometric chromosome sorting followed by sequencing using available next generation (high throughput) sequencing platforms. In this chapter, methodologies for sequencing and assembly of flow sorted chromosomes and whole genomes in cereal crops, with special emphasis on the case of the International Wheat Genome Sequencing Consortium (IWGSC), are reviewed.


Assuntos
Cromossomos de Plantas , Biologia Computacional , Genoma de Planta , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA , Mapeamento Cromossômico/métodos , Biologia Computacional/métodos , DNA de Plantas , Bases de Dados Genéticas , Grão Comestível/genética , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Técnicas de Amplificação de Ácido Nucleico , Análise de Sequência de DNA/métodos
10.
Gigascience ; 6(4): 1-5, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28327910

RESUMO

Background: Research projects often involve observation, registration, and data processing starting from information obtained in field experiments. In many cases, these tasks are carried out by several persons in different places, times, and ways, adding different levels of complexity and error in data collecting. Furthermore, data processing can be time consuming, and input errors may produce unwanted results. Results: We have developed a novel, open source software called Phenobook, an easy, flexible, and intuitive tool to organize, collect, and save experimental data for further analyses. Phenobook was conceived to collect phenotypic observations in a user-friendly, cost-effective way. It consists of a web-based software for experiment design, data input and visualization, and exportation, combined with a mobile application for remote data collecting. We provide in this article a detailed description of the developed tool. Conclusion: Phenobook is a software tool that can be easily implemented in collaborative research and development projects involving data collecting and forward analyses. Adopting Phenobook is expected to improve the involved processes by minimizing input errors, resulting in higher quality and reliability of the research outcomes.


Assuntos
Fenótipo , Software , Bases de Dados Genéticas , Estudos de Associação Genética/métodos , Interface Usuário-Computador , Navegador
11.
Plant Sci ; 233: 200-212, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25711827

RESUMO

Survey sequencing of the bread wheat (Triticum aestivum L.) genome (AABBDD) has been approached through different strategies delivering important information. However, the current wheat sequence knowledge is not complete. The aim of our study is to provide different and complementary set of data for chromosome 4D. A survey sequence was obtained by pyrosequencing of flow-sorted 4DS (7.2×) and 4DL (4.1×) arms. Single ends (SE) and long mate pairs (LMP) reads were assembled into contigs (223Mb) and scaffolds (65Mb) that were aligned to Aegilops tauschii draft genome (DD), anchoring 34Mb to chromosome 4. Scaffolds annotation rendered 822 gene models. A virtual gene order comprising 1973 wheat orthologous gene loci and 381 wheat gene models was built. This order was largely consistent with the scaffold order determined based on a published high density map from the Ae. tauschii chromosome 4, using bin-mapped 4D ESTs as a common reference. The virtual order showed a higher collinearity with homeologous 4B compared to 4A. Additionally, a virtual map was constructed and ∼5700 genes (∼2200 on 4DS and ∼3500 on 4DL) predicted. The sequence and virtual order obtained here using the 454 platform were compared with the Illumina one used by the IWGSC, giving complementary information.


Assuntos
Cromossomos de Plantas , Ordem dos Genes , Triticum/genética , Mapeamento Cromossômico , Etiquetas de Sequências Expressas/química , Sequenciamento de Nucleotídeos em Larga Escala , Dados de Sequência Molecular , Análise de Sequência de DNA
12.
Plant Dis ; 81(9): 1005-1010, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30861950

RESUMO

A cDNA library representing the genomes of several garlic viruses was generated using a viral RNA mixture as template. Analysis of randomly selected clones allowed the identification of different viral genomic sequences. On the basis of amino acid and nucleotide sequence comparisons, one of them was assigned to garlic virus A (GarV-A), a novel flexuous, rod-shaped virus recently reported in Japan. The coat protein (CP) of this virus was expressed in Escherichia coli cells and used as immunogen to produce polyclonal antibodies. The expression protein was recognized by an antiserum detecting garlic mite-borne filamentous virus, but did not react with antibodies specific for other garlic viruses. Antibodies raised against the viral CP reacted with extracts infected with garlic mite-borne viruses and fail to recognize preparations of onion yellow dwarf potyvirus, leek yellow stripe potyvirus, and carnation latent carlavirus. The same antibodies decorated viral particles exhibiting a modal length of 586 nm in immuno electron microscopy with decoration assays. Double-antibody enzyme-linked immunosorbent assays and tissue printing assays performed with these antibodies allowed detection of GarV-A in most garlic cultivars used in Argentina.

13.
Artigo em Inglês | MEDLINE | ID: mdl-23882394

RESUMO

Phrenic nerve palsy has been recognized as a complication of catheter ablation with a prevalence of 0.11-0.48% after atrial fibrillation ablation, independent of the type of ablation catheter or energy source, likely due to the anatomical relationship of the nerves. This report describes a case of new onset of shortness of breath (SOB) due to left diaphragm paralysis following transcatheter radiofrequency ablation in a patient with underlying chronic obstructive pulmonary disease.

14.
Curr Probl Diagn Radiol ; 42(4): 141-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23795993

RESUMO

Postcardiac injury syndrome (PCIS) is a frequent clinical entity developing as a complication of cardiac procedures. Some of these may be only minor procedures, such as the insertion of permanent pacer or defibrillator devices. The purpose of this article is to review and illustrate its common imaging findings. PCIS is expected to occur in approximately 1%-2% of patients after pacer or defibrillator device placement. The mechanism of pericarditis following implantation is unclear, but it may involve a direct irritation of the pericardium by minimally protruding electrodes, low-grade bleeding with hemorrhagic pericarditis, and a late autoimmune or inflammatory response to those insults. Radiologists may detect findings that in the appropriate clinical setting should raise the possibility of PCIS. On chest x-ray, the findings include the presence of a pericardial or pleural effusion or both. Computed tomography, in addition to having better characterization capabilities of the pericardial or pleural effusion or both, may also accomplish the diagnosis of lead perforation. Although typically rather benign, PCIS may result in significant morbidity and potential mortality due to arrhythmias, noncardiac pulmonary edema, and cardiac tamponade. Therefore, its early detection is of clinical importance.


Assuntos
Desfibriladores Implantáveis/efeitos adversos , Eletrodos Implantados/efeitos adversos , Traumatismos Cardíacos/diagnóstico , Traumatismos Cardíacos/etiologia , Marca-Passo Artificial/efeitos adversos , Tomografia Computadorizada por Raios X , Ferimentos Penetrantes/diagnóstico , Ferimentos Penetrantes/etiologia , Diagnóstico Diferencial , Traumatismos Cardíacos/fisiopatologia , Humanos , Derrame Pericárdico/diagnóstico , Derrame Pericárdico/etiologia , Pericardite/diagnóstico , Pericardite/etiologia , Derrame Pleural/diagnóstico , Derrame Pleural/etiologia , Síndrome , Ferimentos Penetrantes/fisiopatologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-23882389

RESUMO

Deglutition syncope has been demonstrated in isolated case reports, the first being described over 50 years ago. It is thought to be caused by a hypersensitive vagotonic reflex in response to esophageal dilation after swallowing. It can cause syncope due to complete atrioventricular (AV) block and acute reduction of cardiac output. Although rare, its lethality is worthy of discussion, as early recognition can offer complete treatment with placement of a pacemaker. A 54-year-old man presented with 30 years of lightheadedness and syncope, followed by disorientation and tremors, after eating sandwiches or drinking carbonated beverages. He initially was evaluated by a neurologist. Work-up included cardiac 2D transthoracic echocardiogram, electroencephalogram, swallow stud, pulmonary function tests, electrocardiogram, and cardiac stress testing. All tests were within normal limits, and it was determined that he was suffering from convulsive syncope and deglutition syncope. Referral to the cardiac electrophysiology department with tilt-table testing accompanied by swallow evaluation was then recommended. The tests demonstrated marked vagal response resulting in sinus bradycardia with second-degree AV block and pauses up to 3.5 seconds. Patient experienced near syncope. A rate-responsive, dual-chamber Boston Scientific pacemaker with DDDR programming was implanted. Patient has remained asymptomatic at follow-up.

18.
Am J Cardiol ; 105(2): 153-7, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-20102910

RESUMO

More than 10 million people, many elderly and likely to harbor cardiovascular (CV) disease, embark on cruise ship travel worldwide every year. The clinical presentation and outcome of CV emergencies presenting during cruise ship travel remain largely unknown. Our department provides contracted cardiology consultations to several large cruise lines. We prospectively maintained a registry of all such consultations during a 2-year period. One hundred consecutive patients were identified (age 66 +/- 14 years, range 18 to 90, 76% men). The most common symptom was chest pain (50%). The most common diagnosis was acute coronary syndrome (58%; ST elevation in 21% and non-ST elevation in 37%). On-board mortality was 3%. Overall, 73% of patients required hospital triage. Of the 25 patients triaged to our institution, 17 underwent a revascularization procedure. One patient died. Ten percent of patients had cardiac symptoms in the days or weeks before boarding; all required hospital triage. Access to a baseline electrocardiogram would have been clinically useful in 23% of cases. In conclusion, CV emergencies, such as acute coronary syndrome and heart failure, are not uncommon on cruise ships. They are often serious, requiring hospital triage and coronary revascularization. A pretravel medical evaluation is recommended for passengers with a cardiac history or a high-risk profile. Passengers should be encouraged to bring a copy of their electrocardiogram on board if abnormal. Cruise lines should establish mechanisms for prompt consultation and triage.


Assuntos
Doenças Cardiovasculares/epidemiologia , Emergências/epidemiologia , Navios , Viagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/terapia , Estudos de Coortes , Feminino , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
19.
Electron. j. biotechnol ; 14(3): 9-9, May 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-602986

RESUMO

Leaf rust, caused by Puccinia triticina Eriks. is a common and widespread disease of bread wheat (Triticum aestivum L.), in Argentina. Host resistance is the most economical, effective and ecologically sustainable method of controlling the disease. Gene postulation helps to determine leaf rust resistance genes (Lr genes) that may be present in a large group of wheat germplasm. Additionally presence of Lr genes can be determined using associated molecular markers. The objective of this study was to identify Lr genes that condition leaf rust resistance in 66 wheat cultivars from Argentina. Twenty four differential lines with individual known leaf rust resistance genes were tested with 17 different pathotypes of leaf rust collected from Argentina. Leaf rust infection types produced on seedling plants of the 66 local cultivars were compared with the infection types produced by the same pathotypes on Lr differentials to postulate which seedling leaf rust genes were present. Presence of Lr9, Lr10, Lr19, Lr20, Lr21, Lr24, Lr25, Lr26, Lr29, Lr34, Lr35, Lr37, Lr47 and Lr51 was also determined using molecular markers. Eleven different Lr genes were postulated in the material: Lr1, Lr3a, Lr3ka, Lr9, Lr10, Lr16, Lr17, Lr19, Lr24, Lr26, Lr41. Presence of Lr21, Lr25, Lr29, and Lr47 could not be determined with the seventeen pathotypes used in the study because all were avirulent to these genes. Eleven cultivars (16.7 percent) were resistant to all pathotypes used in the study and the remaining 55 (83.3 percent) showed virulent reaction against one or more local pathotypes. Cultivars with seedling resistance gene combinations including Lr16 or single genes Lr47 (detected with molecular marker), Lr19 and Lr41, showed high levels of resistance against all pathotypes or most of them. On the opposite side, cultivars with seedling resistance genes Lr1, Lr3a, Lr3a + Lr24, Lr10, Lr3a + Lr10, Lr3a + Lr10 + Lr24 showed the highest number of virulent reactions against local...


Assuntos
Marcadores Genéticos , Genes de Plantas/genética , Imunidade Inata/genética , Controle Biológico de Vetores , Triticum/genética , Triticum/microbiologia , Argentina , Pão , Basidiomycota/fisiologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Reação em Cadeia da Polimerase
20.
Mol Genet Genomics ; 273(1): 54-65, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15690172

RESUMO

The broad adaptability of wheat and barley is in part attributable to their flexible growth habit, in that spring forms have recurrently evolved from the ancestral winter growth habit. In diploid wheat and barley growth habit is determined by allelic variation at the VRN-1 and/or VRN-2 loci, whereas in the polyploid wheat species it is determined primarily by allelic variation at VRN-1. Dominant Vrn-A1 alleles for spring growth habit are frequently associated with mutations in the promoter region in diploid wheat and in the A genome of common wheat. However, several dominant Vrn-A1, Vrn-B1, Vrn-D1 (common wheat) and Vrn-H1 (barley) alleles show no polymorphisms in the promoter region relative to their respective recessive alleles. In this study, we sequenced the complete VRN-1 gene from these accessions and found that all of them have large deletions within the first intron, which overlap in a 4-kb region. Furthermore, a 2.8-kb segment within the 4-kb region showed high sequence conservation among the different recessive alleles. PCR markers for these deletions showed that similar deletions were present in all the accessions with known Vrn-B1 and Vrn-D1 alleles, and in 51 hexaploid spring wheat accessions previously shown to have no polymorphisms in the VRN-A1 promoter region. Twenty-four tetraploid wheat accessions had a similar deletion in VRN-A1 intron 1. We hypothesize that the 2.8-kb conserved region includes regulatory elements important for the vernalization requirement. Epistatic interactions between VRN-H2 and the VRN-H1 allele with the intron 1 deletion suggest that the deleted region may include a recognition site for the flowering repression mediated by the product of the VRN-H2 gene of barley.


Assuntos
Alelos , Proteínas de Ligação a DNA/genética , Hordeum/genética , Proteínas Repressoras/genética , Estações do Ano , Deleção de Sequência/genética , Triticum/genética , Argentina , Sequência de Bases , California , Primers do DNA , Hordeum/crescimento & desenvolvimento , Íntrons/genética , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNA , Triticum/crescimento & desenvolvimento
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