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1.
Nat Commun ; 11(1): 4393, 2020 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-32879321

RESUMO

Rcr3 is a secreted protease of tomato that is targeted by fungal effector Avr2, a secreted protease inhibitor of the fungal pathogen Cladosporium fulvum. The Avr2-Rcr3 complex is recognized by receptor-like protein Cf-2, triggering hypersensitive cell death (HR) and disease resistance. Avr2 also targets Rcr3 paralog Pip1, which is not required for Avr2 recognition but contributes to basal resistance. Thus, Rcr3 acts as a guarded decoy in this interaction, trapping the fungus into a recognition event. Here we show that Rcr3 evolved > 50 million years ago (Mya), whereas Cf-2 evolved <6Mya by co-opting the pre-existing Rcr3 in the Solanum genus. Ancient Rcr3 homologs present in tomato, potato, eggplants, pepper, petunia and tobacco can be inhibited by Avr2 with the exception of tobacco Rcr3. Four variant residues in Rcr3 promote Avr2 inhibition, but the Rcr3 that co-evolved with Cf-2 lacks three of these residues, indicating that the Rcr3 co-receptor is suboptimal for Avr2 binding. Pepper Rcr3 triggers HR with Cf-2 and Avr2 when engineered for enhanced inhibition by Avr2. Nicotiana benthamiana (Nb) is a natural null mutant carrying Rcr3 and Pip1 alleles with deleterious frame-shift mutations. Resurrected NbRcr3 and NbPip1 alleles were active proteases and further NbRcr3 engineering facilitated Avr2 inhibition, uncoupled from HR signalling. The evolution of a receptor co-opting a conserved pathogen target contrasts with other indirect pathogen recognition mechanisms.


Assuntos
Cladosporium , Resistência à Doença/genética , Peptídeo Hidrolases/genética , Imunidade Vegetal/genética , Solanum , Tabaco , Cladosporium/genética , Cladosporium/metabolismo , Cladosporium/patogenicidade , Evolução Molecular , Proteínas Fúngicas/metabolismo , Genes de Plantas , Interações Hospedeiro-Parasita , Peptídeo Hidrolases/metabolismo , Filogenia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Inibidores de Proteases/metabolismo , Solanum/genética , Solanum/metabolismo , Solanum/microbiologia , Tabaco/genética , Tabaco/metabolismo , Tabaco/microbiologia
2.
Nat Commun ; 11(1): 4382, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873802

RESUMO

Fusarium graminearum is a causal agent of Fusarium head blight (FHB) and a deoxynivalenol (DON) producer. In this study, OSP24 is identified as an important virulence factor in systematic characterization of the 50 orphan secreted protein (OSP) genes of F. graminearum. Although dispensable for growth and initial penetration, OSP24 is important for infectious growth in wheat rachis tissues. OSP24 is specifically expressed during pathogenesis and its transient expression suppresses BAX- or INF1-induced cell death. Osp24 is translocated into plant cells and two of its 8 cysteine-residues are required for its function. Wheat SNF1-related kinase TaSnRK1α is identified as an Osp24-interacting protein and shows to be important for FHB resistance in TaSnRK1α-overexpressing or silencing transgenic plants. Osp24 accelerates the degradation of TaSnRK1α by facilitating its association with the ubiquitin-26S proteasome. Interestingly, TaSnRK1α also interacts with TaFROG, an orphan wheat protein induced by DON. TaFROG competes against Osp24 for binding with the same region of TaSnRKα and protects it from degradation. Overexpression of TaFROG stabilizes TaSnRK1α and increases FHB resistance. Taken together, Osp24 functions as a cytoplasmic effector by competing against TaFROG for binding with TaSnRK1α, demonstrating the counteracting roles of orphan proteins of both host and fungal pathogens during their interactions.


Assuntos
Proteínas Fúngicas/metabolismo , Fusarium/patogenicidade , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Triticum/microbiologia , Fatores de Virulência/metabolismo , Resistência à Doença , Fusarium/imunologia , Fusarium/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Plantas Geneticamente Modificadas , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/imunologia , Proteólise , Tricotecenos/metabolismo , Triticum/imunologia
3.
Nat Commun ; 11(1): 4447, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32895382

RESUMO

Tea is an economically important plant characterized by a large genome, high heterozygosity, and high species diversity. In this study, we assemble a 3.26-Gb high-quality chromosome-scale genome for the 'Longjing 43' cultivar of Camellia sinensis var. sinensis. Genomic resequencing of 139 tea accessions from around the world is used to investigate the evolution and phylogenetic relationships of tea accessions. We find that hybridization has increased the heterozygosity and wide-ranging gene flow among tea populations with the spread of tea cultivation. Population genetic and transcriptomic analyses reveal that during domestication, selection for disease resistance and flavor in C. sinensis var. sinensis populations has been stronger than that in C. sinensis var. assamica populations. This study provides resources for marker-assisted breeding of tea and sets the foundation for further research on tea genetics and evolution.


Assuntos
Camellia sinensis/genética , Resistência à Doença/genética , Evolução Molecular , Genoma de Planta/genética , Melhoramento Vegetal , Domesticação , Perfilação da Expressão Gênica , Genômica , Filogenia , Polimorfismo de Nucleotídeo Único
4.
Phytopathology ; 110(10): 1721-1726, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32915112

RESUMO

Stem rust is an important disease of cultivated oat (Avena sativa) caused by Puccinia graminis f. sp. avenae. In North America, host resistance is the primary strategy to control this disease and is conferred by a relatively small number of resistance genes. Pg2 is a widely deployed stem rust resistance gene that originates from cultivated oat. Oat breeders wish to develop cultivars with multiple Pg genes to slow the breakdown of single gene resistance, and often require DNA markers suited for marker-assisted selection. Our objectives were to (i) construct high density linkage maps for a major oat stem rust resistance gene using three biparental mapping populations, (ii) develop Kompetitive allele-specific PCR (KASP) assays for Pg2-linked single-nucleotide polymorphisms (SNPs), and (iii) test the prediction accuracy of those markers with a diverse panel of spring oat lines and cultivars. Genotyping-by-sequencing SNP markers linked to Pg2 were identified in an AC Morgan/CDC Morrison recombinant inbred line (RIL) population. Pg2-linked SNPs were then analyzed in an AC Morgan/RL815 F2 population and an AC Morgan/CDC Dancer RIL population. Linkage analysis identified a common location for Pg2 in all three populations on linkage group Mrg20 of the oat consensus genetic map. The most predictive markers were identified and converted to KASP assays for use in oat breeding programs. When used in combination, the KASP assays for the SNP loci avgbs2_126549.1.46 and avgbs_cluster_23819.1.27 were highly predictive of Pg2 status in panel of 54 oat breeding lines and cultivars.


Assuntos
Avena/genética , Basidiomycota , Mapeamento Cromossômico , Resistência à Doença/genética , Ligação Genética , Humanos , América do Norte , Doenças das Plantas , Polimorfismo de Nucleotídeo Único/genética
5.
Nat Commun ; 11(1): 3849, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737300

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr Virus (EBV) establish life-long infections and are associated with malignancies. Striking geographic variation in incidence and the fact that virus alone is insufficient to cause disease, suggests other co-factors are involved. Here we present epidemiological analysis and genome-wide association study (GWAS) in 4365 individuals from an African population cohort, to assess the influence of host genetic and non-genetic factors on virus antibody responses. EBV/KSHV co-infection (OR = 5.71(1.58-7.12)), HIV positivity (OR = 2.22(1.32-3.73)) and living in a more rural area (OR = 1.38(1.01-1.89)) are strongly associated with immunogenicity. GWAS reveals associations with KSHV antibody response in the HLA-B/C region (p = 6.64 × 10-09). For EBV, associations are identified for VCA (rs71542439, p = 1.15 × 10-12). Human leucocyte antigen (HLA) and trans-ancestry fine-mapping substantiate that distinct variants in HLA-DQA1 (p = 5.24 × 10-44) are driving associations for EBNA-1 in Africa. This study highlights complex interactions between KSHV and EBV, in addition to distinct genetic architectures resulting in important differences in pathogenesis and transmission.


Assuntos
Anticorpos Antivirais/biossíntese , Resistência à Doença/genética , Infecções por Vírus Epstein-Barr/genética , Infecções por Henipavirus/genética , Interações Hospedeiro-Patógeno/genética , Sarcoma de Kaposi/genética , Adolescente , Adulto , Antígenos Virais/genética , Antígenos Virais/imunologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Coinfecção , Infecções por Vírus Epstein-Barr/epidemiologia , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/virologia , Antígenos Nucleares do Vírus Epstein-Barr/genética , Antígenos Nucleares do Vírus Epstein-Barr/imunologia , Feminino , Expressão Gênica , Estudo de Associação Genômica Ampla , HIV/genética , HIV/imunologia , HIV/patogenicidade , Cadeias alfa de HLA-DQ/genética , Cadeias alfa de HLA-DQ/imunologia , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/imunologia , Infecções por Henipavirus/virologia , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/patogenicidade , Herpesvirus Humano 8/genética , Herpesvirus Humano 8/imunologia , Herpesvirus Humano 8/patogenicidade , Interações Hospedeiro-Patógeno/imunologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , População Rural , Sarcoma de Kaposi/epidemiologia , Sarcoma de Kaposi/imunologia , Sarcoma de Kaposi/virologia , Uganda/epidemiologia , População Urbana
6.
PLoS One ; 15(8): e0237194, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760135

RESUMO

We aimed to profile the metabolism of soybean roots that were infected with soybean cyst nematodes and treated with Bacillus simplex to identify metabolic differences that may explain nematode resistance. Compared with control soybean roots, B. simplex-treated soybean roots contained lower levels of glucose, fructose, sucrose, and trehalose, which reduced the nematodes' food source. Furthermore, treatment with B. simplex led to higher levels of melibiose, gluconic acid, lactic acid, phytosphingosine, and noradrenaline in soybean roots, which promoted nematocidal activity. The levels of oxoproline, maltose, and galactose were lowered after B. simplex treatment, which improved disease resistance. Collectively, this study provides insight into the metabolic alterations induced by B. simplex treatment, which affects the interactions with soybean cyst nematodes.


Assuntos
Bacillus/patogenicidade , Resistência à Doença , Metaboloma , Nematoides/patogenicidade , Soja/parasitologia , Animais , Metabolismo dos Carboidratos , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Raízes de Plantas/parasitologia , Soja/metabolismo , Soja/microbiologia
7.
Med Hypotheses ; 143: 110148, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32759016

RESUMO

Estrogen hormone acts as a potential key player in providing immunity against certain viral infection. It is found to be associated in providing immunity against acute lungs inflammation and influenza virus by modulating cytokines storm and mediating adaptive immune alterations respectively. Women are less affected by SARS-CoV-2 infection because of the possible influence of estrogen hormone as compared to men. We hypothesized that SARS-CoV-2 causes stress in endoplasmic reticulum (ER) which in turn aggravates the infection, estrogen hormone might play key role in decreasing ER stress by activating estrogen mediated signaling pathways, results in unfolded protein response (UPR). Estrogen governs degradation of phosphotidylinositol 4,5-bisphosphate (PIP2) into diacylglycerol (DAG) and inositol triphosphate (IP3) with the help of phospholipase C. IP3 start in-fluxing Ca+2 ions that helps in UPR activation. To support our hypothesis, we analyzed the data of 162,392 COVID-19 patients to determine the relation of this disease with gender. We observed that 26% of women and 74% of men were affected by SARS-CoV-2. It indicated that women are less affected because of the possible influence of estrogen hormone in women.


Assuntos
Betacoronavirus , Infecções por Coronavirus/fisiopatologia , Estresse do Retículo Endoplasmático/fisiologia , Estrogênios/fisiologia , Modelos Biológicos , Pandemias , Pneumonia Viral/fisiopatologia , Adulto , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/metabolismo , Conjuntos de Dados como Assunto/estatística & dados numéricos , Diglicerídeos/metabolismo , Resistência à Doença , Feminino , Humanos , Inositol 1,4,5-Trifosfato/metabolismo , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Fosfatidilinositol 4,5-Difosfato/metabolismo , Pneumonia Viral/epidemiologia , Pneumonia Viral/metabolismo , Caracteres Sexuais , Distribuição por Sexo , Transdução de Sinais , Fosfolipases Tipo C/metabolismo , Resposta a Proteínas não Dobradas , Proteínas Virais/biossíntese , Proteínas Virais/genética
8.
Med Hypotheses ; 143: 110151, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32763661

RESUMO

Today it remains unclear why children seem to be less likely to get infected by COVID-19 or why they appear to be less symptomatic after infections. All individuals, especially children, are exposed to various viruses including human coronavirus (CoVs) that can generally lead to respiratory infections. We hypothesize that recurrent CoVs exposure may induce an effective antiviral B and T-cell-mediated adaptive immune response, which could also be protective against COVID-19. Based on the high-homology between the Spike protein epitopes of taxonomically-related coronaviruses, we theorize that past/recurrent contact with CoVs might shield children also against the circulating COVID-19 through a possible neutralizing antibody response previously CoVs-induced. This would open up possible lines of research for the development of live-attenuated virus vaccines from CoVs. Future research is desirable to confirm or disprove such hypothesis.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Memória Imunológica , Modelos Imunológicos , Pandemias , Pneumonia Viral/epidemiologia , Adulto , Distribuição por Idade , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Antígenos Virais/genética , Antígenos Virais/imunologia , Betacoronavirus/genética , Betacoronavirus/imunologia , Linfócitos T CD4-Positivos/imunologia , Criança , Coronavirus/genética , Coronavirus/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Reações Cruzadas , Resistência à Doença , Epitopos/genética , Epitopos/imunologia , Humanos , Peptidil Dipeptidase A/análise , Pneumonia Viral/imunologia , Alvéolos Pulmonares/química , Receptores Virais/análise , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/virologia , Homologia de Sequência de Aminoácidos , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Atenuadas , Vacinas Virais
9.
Med Hypotheses ; 143: 110153, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32763662

RESUMO

Reports from various countries suggest that tobacco smoking might protect from SARS-CoV-2 infection, since the prevalence of smoking in COVID-19 hospitalized patients is lower than in the respective general population. Apart from nicotine or other chemicals contained in tobacco smoke, we propose that a single-stranded RNA virus that infects tobacco leaves, tobacco mosaic virus (TMV), might be implicated in this effect. TMV, though non-pathogenic, is found in smokers' airways, and stimulates adaptive and innate immunity, with release of specific antibodies and interferons. The latter may have preventive and/or therapeutic effects against COVID-19. If confirmed by epidemiological and interventional studies, this might lead to the use of TMV as an immunological adjuvant against SARS-CoV-2 infection and COVID-19 disease.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Modelos Imunológicos , Pandemias , Pneumonia Viral/imunologia , Fumantes , Vírus do Mosaico do Tabaco/imunologia , Produtos do Tabaco/virologia , Fumar Tabaco , Animais , Anticorpos Antivirais/biossíntese , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Resistência à Doença , Humanos , Interferons/biossíntese , Camundongos , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Sistema Respiratório/imunologia , Sistema Respiratório/virologia , Vírus do Mosaico do Tabaco/isolamento & purificação , Fumar Tabaco/epidemiologia , Receptores Toll-Like/imunologia
10.
PLoS One ; 15(8): e0237741, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804977

RESUMO

Region-specific local landraces represent a germplasm diversity adapted and acclimatized to local conditions, and are ideal to breed for targeted market niches while maintaining the variability of heirloom traits. A collection of 180 pepper accessions, collected from 62 diverse locations across six Balkan countries, were characterized and evaluated for phenotypic and biochemical variation during a multi-year environment. An assortment of 32 agro-morphological, fruit quality, and virus resistance traits were evaluated, and the top 10% accessions were identified. A wide range of trait variation concerning plant architecture, inflorescence and fruit traits, yield and fruit quality was observed, and appreciable variation was noticed. According to hierarchical clustering, six distinct clusters were established based on pre-defined varietal groups. Divergence among accessions for phenotypic and fruit compositional variability was analyzed, and eight principal components were identified that contributed ~71% of the variation, with fruit shape, width, wall thickness, weight, and fruit quality traits being the most discriminant. Evaluation of the response to tobacco mosaic virus (TMV) and pepper mild mottle mosaic virus (PMMoV) showed that 24 and 1 accession were resistant, respectively while no tomato spotted wilt virus (TSWV) resistance was found. Considerable diversity for agro-bio-morphological traits indicates the Balkan pepper collection as good gene sources for pre-breeding and cultivar development that are locally adapted.


Assuntos
Capsicum/genética , Resistência à Doença/genética , Melhoramento Vegetal , Locos de Características Quantitativas/genética , Península Balcânica , Capsicum/química , Capsicum/virologia , Frutas/química , Frutas/genética , Frutas/virologia , Variação Genética , Fenótipo , Tobamovirus/patogenicidade , Tospovirus/patogenicidade
11.
PLoS One ; 15(8): e0238148, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32822425

RESUMO

Root treatment with oxathiapiprolin, benthiavalicarb or their mixture Zorvec-Endavia [ZE (3+7, w/w)] was shown to provide prolonged systemic protection against foliar oomycete pathogens attacking cucumber, tomato and basil. Here we report that these fungicides can effectively protect potato plants against late blight when applied to the soil in which such potato plants are grown. In two field experiments, performed in 2019 and 2020, potato plants grown in 64 L containers were treated with a soil drench of oxathiapiprolin, benthiavalicarb or ZE at 12.5, 25 or 50 mg ai/five plants in a container. Artificial inoculations with Phytophthora infestans revealed that such treated plants were protected against late blight in a dose-dependent manner all along the season. Interestingly, oxathiapiprolin persisted in the treated soil for at least 139 days, providing systemic protection against late blight to the following potato crops grown in that treated soils. Potato plants grown in loess soil in the field were either sprayed or drenched with ZE. Plants treated via the soil were significantly better protected against late blight compared to the plants treated by a spray. The data demonstrate a new strategy for season-long protection of potato against late blight by a single soil application of ZE. The systemic nature of oxathiapiprolin and benthiavalicarb composing ZE assures the translocation to the foliage of two fungicides with different modes of action. This shall minimize the risk of developing resistance against either fungicide in the treated crops.


Assuntos
Hidrocarbonetos Fluorados/administração & dosagem , Hidrocarbonetos Fluorados/farmacologia , Doenças das Plantas/prevenção & controle , Pirazóis/administração & dosagem , Pirazóis/farmacologia , Resistência à Doença/genética , Fungicidas Industriais/farmacologia , Phytophthora infestans/efeitos dos fármacos , Phytophthora infestans/patogenicidade , Raízes de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Solo , Solanum tuberosum/microbiologia
12.
Plant Dis ; 104(10): 2658-2664, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32749944

RESUMO

There has not been a major wheat stem rust epidemic worldwide since the 1970s, but the emergence of race TTKSK of Puccinia graminis f. sp. tritici in 1998 presented a great threat to the world wheat production. Single disease-resistance genes are usually effective for only several years before the pathogen changes genetically to overcome the resistance. Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is one of the most common and persistent wheat diseases worldwide. The development of varieties with multiple resistance is the most economical and effective strategy for preventing stripe rust and stem rust, the two main rust diseases constraining wheat production. Plateau 448 has been widely used in the spring wheat growing region in northwest China, but it has become susceptible to stripe rust and is susceptible to TTKSK. To produce more durable resistance to race TTKSK as well as to stripe rust, four stem rust resistance genes (Sr33, Sr36, Sr-Cad, and Sr43) and three stripe rust resistance genes (Yr5, Yr18, and Yr26) were simultaneously introgressed into Plateau 448 to improve its stem rust (Ug99) and stripe rust resistance using a marker-assisted backcrossing strategy combined with phenotypic selection. We obtained 131 BC1F5 lines that pyramided two to four Ug99 resistance genes and one to two Pst resistance genes simultaneously. Thirteen of these lines were selected for their TTKSK resistance, and all of them exhibited near immunity or high resistance to TTKSK. Among the 131 pyramided lines, 95 showed high resistance to mixed Pst races. Nine lines exhibited not only high resistance to TTKSK and Pst but also better agronomic traits and high-molecular-weight glutenin subunit compositions than Plateau 448.


Assuntos
Basidiomycota , Doenças das Plantas/genética , Cruzamento , China , Resistência à Doença/genética , Humanos
13.
PLoS One ; 15(8): e0236674, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32756600

RESUMO

In Sub-Saharan Africa cassava (Manihot esculenta Crantz) is one of the most important food crops where more than 40% of the population relies on it as their staple carbohydrate source. Biotic constraints such as viral diseases, mainly Cassava Mosaic Disease (CMD) and Cassava Brown Streak Disease (CBSD), and arthropod pests, particularly Cassava Green Mite (CGM), are major constraints to the realization of cassava's full production potential in Africa. To address these problems, we aimed to map the quantitative trait loci (QTL) associated with resistance to CBSD foliar and root necrosis symptoms, foliar CMD and CGM symptoms in a full-sib mapping population derived from the genotypes AR40-6 and Albert. A high-density linkage map was constructed with 2,125 SNP markers using a genotyping-by-sequencing approach. For phenotyping, clonal evaluation trials were conducted with 120 F1 individuals for two consecutive field seasons using an alpha-lattice design at Chambezi and Naliendele, Tanzania. Previously identified QTL for resistance to CBSD foliar symptoms were corroborated, and a new putative QTL for CBSD root necrosis identified (qCBSDRNc14AR) from AR40-6. Two QTL were identified within the region of the previously recognized CMD2 locus from this population in which both parents are thought to possess the CMD2 locus. Interestingly, a minor but consistent QTL, qCGM18AR, for CGM resistance at 3 months after planting stage was also detected and co-localized with a previously identified SSR marker, NS346, linked with CGM resistance. Markers underlying these QTL may be used to increase efficiencies in cassava breeding programs.


Assuntos
Resistência à Doença/genética , Manihot/genética , Doenças das Plantas/genética , Locos de Características Quantitativas/genética , Cruzamento , Testes Genéticos , Genótipo , Manihot/fisiologia , Manihot/virologia , Doenças das Plantas/virologia , Potyviridae/genética , Potyviridae/patogenicidade , Estresse Fisiológico/genética , Tanzânia
14.
Infect Genet Evol ; 84: 104498, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32771700

RESUMO

New coronavirus SARS-CoV-2 is capable to infect humans and cause a novel disease COVID-19. Aiming to understand a host genetic component of COVID-19, we focused on variants in genes encoding proteases and genes involved in innate immunity that could be important for susceptibility and resistance to SARS-CoV-2 infection. Analysis of sequence data of coding regions of FURIN, PLG, PRSS1, TMPRSS11a, MBL2 and OAS1 genes in 143 unrelated individuals from Serbian population identified 22 variants with potential functional effect. In silico analyses (PolyPhen-2, SIFT, MutPred2 and Swiss-Pdb Viewer) predicted that 10 variants could impact the structure and/or function of proteins. These protein-altering variants (p.Gly146Ser in FURIN; p.Arg261His and p.Ala494Val in PLG; p.Asn54Lys in PRSS1; p.Arg52Cys, p.Gly54Asp and p.Gly57Glu in MBL2; p.Arg47Gln, p.Ile99Val and p.Arg130His in OAS1) may have predictive value for inter-individual differences in the response to the SARS-CoV-2 infection. Next, we performed comparative population analysis for the same variants using extracted data from the 1000 Genomes project. Population genetic variability was assessed using delta MAF and Fst statistics. Our study pointed to 7 variants in PLG, TMPRSS11a, MBL2 and OAS1 genes with noticeable divergence in allelic frequencies between populations worldwide. Three of them, all in MBL2 gene, were predicted to be damaging, making them the most promising population-specific markers related to SARS-CoV-2 infection. Comparing allelic frequencies between Serbian and other populations, we found that the highest level of genetic divergence related to selected loci was observed with African, followed by East Asian, Central and South American and South Asian populations. When compared with European populations, the highest divergence was observed with Italian population. In conclusion, we identified 4 variants in genes encoding proteases (FURIN, PLG and PRSS1) and 6 in genes involved in the innate immunity (MBL2 and OAS1) that might be relevant for the host response to SARS-CoV-2 infection.


Assuntos
Infecções por Coronavirus/genética , Resistência à Doença/genética , Predisposição Genética para Doença , Interações Hospedeiro-Patógeno/genética , Metagenômica , Peptidil Dipeptidase A/genética , Pneumonia Viral/genética , Glicoproteína da Espícula de Coronavírus/genética , Alelos , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Proteínas do Olho/genética , Proteínas do Olho/imunologia , Furina/genética , Furina/imunologia , Frequência do Gene , Variação Genética , Genoma Humano , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Inata , Lectina de Ligação a Manose/genética , Lectina de Ligação a Manose/imunologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Pandemias , Peptidil Dipeptidase A/imunologia , Plasminogênio/genética , Plasminogênio/imunologia , Pneumonia Viral/imunologia , Ligação Proteica , Glicoproteína da Espícula de Coronavírus/imunologia , Tripsina/genética , Tripsina/imunologia
15.
PLoS One ; 15(8): e0236633, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785249

RESUMO

The induction of general plant defense responses following the perception of external elicitors is now regarded as the first level of the plant immune response. Depending on the involvement or not of these molecules in pathogenicity, this induction of defense is called either Pathogen-Associated Molecular Pattern (PAMP) Triggered Immunity or Pattern Triggered Immunity-both abbreviated to PTI. Because PTI is assumed to be a widespread and stable form of resistance to infection, understanding the mechanisms driving it becomes a major goal for the sustainable management of plant-pathogen interactions. However, the induction of PTI is complex. Our hypotheses are that (i) the recognition by the plant of PAMPs vs non-PAMP elicitors leads to specific defense profiles and (ii) the responses specifically induced by PAMPs target critical life history traits of the pathogen that produced them. We thus analyzed, using a metabolomic approach coupled with transcriptomic and hormonal analyses, the defense profiles induced in potato foliage treated with either a Concentrated Culture Filtrate (CCF) from Phytophthora infestans or two non-PAMP preparations, ß-aminobutyric acid (BABA) and an Ulva spp. Extract, used separately. Each elicitor induced specific defense profiles. CCF up-regulated sesquiterpenes but down-regulated sterols and phenols, notably α-chaconine, caffeoyl quinic acid and rutin, which decreased spore production of P. infestans in vitro. CCF thus induces both defense and counter-defense responses. By contrast, the Ulva extract triggered the synthesis of a large-spectrum of antimicrobial compounds through the phenylpropanoid/flavonoid pathways, while BABA targeted the primary metabolism. Hence, PTI can be regarded as a heterogeneous set of general and pathogen-specific responses triggered by the molecular signatures of each elicitor, rather than as a uniform, non-specific and broad-spectrum set of general defense reactions.


Assuntos
Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Imunidade Vegetal/imunologia , Solanum tuberosum/imunologia , Aminobutiratos/farmacologia , Resistência à Doença/efeitos dos fármacos , Flavonoides/biossíntese , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Fenóis/metabolismo , Phytophthora infestans/imunologia , Phytophthora infestans/patogenicidade , Doenças das Plantas/microbiologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Imunidade Vegetal/efeitos dos fármacos , Sesquiterpenos/metabolismo , Solanum tuberosum/crescimento & desenvolvimento , Solanum tuberosum/microbiologia , Esteróis/metabolismo , Ulva/química
16.
PLoS Comput Biol ; 16(7): e1007823, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32614829

RESUMO

Cassava brown streak disease (CBSD) is a rapidly spreading viral disease that affects a major food security crop in sub-Saharan Africa. Currently, there are several proposed management interventions to minimize loss in infected fields. Field-scale data comparing the effectiveness of these interventions individually and in combination are limited and expensive to collect. Using a stochastic epidemiological model for the spread and management of CBSD in individual fields, we simulate the effectiveness of a range of management interventions. Specifically we compare the removal of diseased plants by roguing, preferential selection of planting material, deployment of virus-free 'clean seed' and pesticide on crop yield and disease status of individual fields with varying levels of whitefly density crops under low and high disease pressure. We examine management interventions for sustainable production of planting material in clean seed systems and how to improve survey protocols to identify the presence of CBSD in a field or quantify the within-field prevalence of CBSD. We also propose guidelines for practical, actionable recommendations for the deployment of management strategies in regions of sub-Saharan Africa under different disease and whitefly pressure.


Assuntos
Simulação por Computador , Monitoramento Ambiental/métodos , Manihot , Doenças das Plantas , África ao Sul do Saara , Animais , Resistência à Doença , Abastecimento de Alimentos , Hemípteros , Modelos Estatísticos , Doenças das Plantas/prevenção & controle , Doenças das Plantas/estatística & dados numéricos
17.
Plant Dis ; 104(9): 2411-2417, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32658634

RESUMO

Chinese wheat landrace Youbailan has excellent resistance to powdery mildew caused by Blumeria graminis f. sp. tritici. In the present study, genetic analysis indicated that a recessive gene, tentatively designated pmYBL, was responsible for the powdery mildew resistance of Youbailan. pmYBL was located in the 695-to-715-Mb genomic region of chromosome 7BL, with 19 gene-linked single-nucleotide polymorphism (SNP) markers. It was flanked by SNP1-12 and SNP1-2 with genetic distances of 0.6 and 1.8 centimorgans, respectively. The disease reaction patterns of Youbailan and four cultivars (lines) carrying the powdery mildew (Pm) genes located on chromosome arm 7BL indicated that pmYBL may be allelic or closely linked to these genes. All of the SNP markers linked to pmYBL were diagnostic, indicating that these markers will be useful for pyramiding pmYBL using marker-assisted selection.


Assuntos
Resistência à Doença/genética , Triticum/genética , Mapeamento Cromossômico , Genes de Plantas , Humanos , Doenças das Plantas
18.
Plant Dis ; 104(9): 2369-2376, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32689920

RESUMO

Fusarium head blight (FHB) and stem rust are among the most devastating diseases of wheat worldwide. Fhb1 is the most widely utilized and the only isolated gene for FHB resistance, while Sr2 is a durable stem rust resistance gene used in rust-prone areas. The two loci are closely linked on the short arm of chromosome 3B and the two genes are in repulsion phase among cultivars. With climate change and the shift in Fusarium populations, it is imperative to develop wheat cultivars resistant to both diseases. The present study was dedicated to developing wheat germplasm combining Fhb1 and Sr2 resistance alleles in the International Maize and Wheat Improvement Center (CIMMYT)'s elite cultivars' backgrounds. Four recombinant inbred lines (RILs) in Hartog background that have the resistant Fhb1 and Sr2 alleles in coupled phase linkage were crossed with seven CIMMYT bread wheat lines, resulting in 208 lines. Molecular markers for both genes were employed in addition to the use of pseudo-black chaff (PBC) as a phenotypic marker for the selection of Sr2. At various stages of the selection process, progeny lines were assessed for FHB index, Fusarium damaged kernels (FDK), stem rust, and PBC expression as well as other diseases of interest (stripe rust and leaf spotting diseases). The 25 best lines were selected for CIMMYT's wheat breeding program. In addition to expressing resistance to FHB, most of these 25 lines have an acceptable level of resistance to other tested diseases. These lines will be useful for wheat breeding programs worldwide and potentially speed up the resistance breeding efforts against FHB and stem rust.


Assuntos
Resistência à Doença , Triticum/genética , Cromossomos de Plantas , Marcadores Genéticos , Humanos , Doenças das Plantas
19.
Nat Commun ; 11(1): 3334, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620760

RESUMO

TH17 cells exemplify environmental immune adaptation: they can acquire both a pathogenic and an anti-inflammatory fate. However, it is not known whether the anti-inflammatory fate is merely a vestigial trait, or whether it serves to preserve the integrity of the host tissues. Here we show that the capacity of TH17 cells to acquire an anti-inflammatory fate is necessary to sustain immunological tolerance, yet it impairs immune protection against S. aureus. Additionally, we find that TGF-ß signalling via Smad3/Smad4 is sufficient for the expression of the anti-inflammatory cytokine, IL-10, in TH17 cells. Our data thus indicate a key function of TH17 cell plasticity in maintaining immune homeostasis, and dissect the molecular mechanisms explaining the functional flexibility of TH17 cells with regard to environmental changes.


Assuntos
Homeostase/imunologia , Inflamação/imunologia , Interleucina-10/imunologia , Intestinos/imunologia , Células Th17/imunologia , Animais , Plasticidade Celular/imunologia , Resistência à Doença/genética , Resistência à Doença/imunologia , Células HEK293 , Humanos , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-17/genética , Interleucina-17/imunologia , Interleucina-17/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/imunologia , Staphylococcus aureus/fisiologia , Células Th17/metabolismo , Fator de Crescimento Transformador beta/imunologia , Fator de Crescimento Transformador beta/metabolismo
20.
Immunol Lett ; 226: 38-45, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32659267

RESUMO

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative pathogen of deadly Coronavirus disease-19 (COVID-19) pandemic, which emerged as a major threat to public health across the world. Although there is no clear gender or socioeconomic discrimination in the incidence of COVID-19, individuals who are older adults and/or with comorbidities and compromised immunity have a relatively higher risk of contracting this disease. Since no specific drug has yet been discovered, strengthening immunity along with maintaining a healthy living is the best way to survive this disease. As a healthy practice, calorie restriction in the form of intermittent fasting (IF) in several clinical settings has been reported to promote several health benefits, including priming of the immune response. This dietary restriction also activates autophagy, a cell surveillance system that boosts up immunity. With these prevailing significance in priming host defense, IF could be a potential strategy amid this outbreak to fighting off SARS-CoV-2 infection. Currently, no review so far available proposing IF as an encouraging strategy in the prevention of COVID-19. A comprehensive review has therefore been planned to highlight the beneficial role of fasting in immunity and autophagy, that underlie the possible defense against SARS-CoV-2 infection. The COVID-19 pathogenesis and its impact on host immune response have also been briefly outlined. This review aimed at revisiting the immunomodulatory potential of IF that may constitute a promising preventive approach against COVID-19.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/etiologia , Infecções por Coronavirus/metabolismo , Suscetibilidade a Doenças , Jejum , Interações Hospedeiro-Patógeno , Pneumonia Viral/etiologia , Pneumonia Viral/metabolismo , Autofagia , Restrição Calórica , Resistência à Doença/imunologia , Suscetibilidade a Doenças/imunologia , Jejum/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Humanos , Evasão da Resposta Imune , Imunidade , Pandemias
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