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1.
New Phytol ; 243(4): 1522-1538, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38922927

RESUMO

Leaf mould, caused by Fulvia fulva, is a devastating disease of tomato plants. In many commercial tomato cultivars, resistance to this disease is governed by the Cf-9 locus, which encodes five paralogous receptor-like proteins. Two of these proteins confer resistance: Cf-9C recognises the previously identified F. fulva effector Avr9 and provides resistance during all plant growth stages, while Cf-9B recognises the yet-unidentified F. fulva effector Avr9B and provides mature plant resistance only. In recent years, F. fulva strains have emerged that can overcome the Cf-9 locus, with Cf-9C circumvented through Avr9 deletion. To understand how Cf-9B is circumvented, we set out to identify Avr9B. Comparative genomics, transient expression assays and gene complementation experiments were used to identify Avr9B, while gene sequencing was used to assess Avr9B allelic variation across a world-wide strain collection. A strict correlation between Avr9 deletion and resistance-breaking mutations in Avr9B was observed in strains recently collected from Cf-9 cultivars, whereas Avr9 deletion but no mutations in Avr9B were observed in older strains. This research showcases how F. fulva has evolved to sequentially break down the Cf-9 locus and stresses the urgent need for commercial tomato cultivars that carry novel, stacked resistance genes active against this pathogen.


Assuntos
Resistência à Doença , Doenças das Plantas , Folhas de Planta , Solanum lycopersicum , Solanum lycopersicum/microbiologia , Solanum lycopersicum/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Resistência à Doença/genética , Folhas de Planta/microbiologia , Folhas de Planta/genética , Loci Gênicos , Alelos , Basidiomycota/fisiologia , Mutação/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
3.
Mol Plant Pathol ; 24(5): 474-494, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36790136

RESUMO

Fulvia fulva and Dothistroma septosporum are closely related apoplastic pathogens with similar lifestyles but different hosts: F. fulva is a pathogen of tomato, whilst D. septosporum is a pathogen of pine trees. In 2012, the first genome sequences of these pathogens were published, with F. fulva and D. septosporum having highly fragmented and near-complete assemblies, respectively. Since then, significant advances have been made in unravelling their genome architectures. For instance, the genome of F. fulva has now been assembled into 14 chromosomes, 13 of which have synteny with the 14 chromosomes of D. septosporum, suggesting these pathogens are even more closely related than originally thought. Considerable advances have also been made in the identification and functional characterization of virulence factors (e.g., effector proteins and secondary metabolites) from these pathogens, thereby providing new insights into how they promote host colonization or activate plant defence responses. For example, it has now been established that effector proteins from both F. fulva and D. septosporum interact with cell-surface immune receptors and co-receptors to activate the plant immune system. Progress has also been made in understanding how F. fulva and D. septosporum have evolved with their host plants, whilst intensive research into pandemics of Dothistroma needle blight in the Northern Hemisphere has shed light on the origins, migration, and genetic diversity of the global D. septosporum population. In this review, we specifically summarize advances made in our understanding of the F. fulva-tomato and D. septosporum-pine pathosystems over the last 10 years.


Assuntos
Ascomicetos , Cladosporium , Interações entre Hospedeiro e Microrganismos , Pinus , Ascomicetos/genética , Cladosporium/genética , Pinus/imunologia , Pinus/microbiologia , Genoma Fúngico/genética
4.
BMC Biol ; 20(1): 246, 2022 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-36329441

RESUMO

BACKGROUND: Scab, caused by the biotrophic fungus Venturia inaequalis, is the most economically important disease of apples worldwide. During infection, V. inaequalis occupies the subcuticular environment, where it secretes virulence factors, termed effectors, to promote host colonization. Consistent with other plant-pathogenic fungi, many of these effectors are expected to be non-enzymatic proteins, some of which can be recognized by corresponding host resistance proteins to activate plant defences, thus acting as avirulence determinants. To develop durable control strategies against scab, a better understanding of the roles that these effector proteins play in promoting subcuticular growth by V. inaequalis, as well as in activating, suppressing, or circumventing resistance protein-mediated defences in apple, is required. RESULTS: We generated the first comprehensive RNA-seq transcriptome of V. inaequalis during colonization of apple. Analysis of this transcriptome revealed five temporal waves of gene expression that peaked during early, mid, or mid-late infection. While the number of genes encoding secreted, non-enzymatic proteinaceous effector candidates (ECs) varied in each wave, most belonged to waves that peaked in expression during mid-late infection. Spectral clustering based on sequence similarity determined that the majority of ECs belonged to expanded protein families. To gain insights into function, the tertiary structures of ECs were predicted using AlphaFold2. Strikingly, despite an absence of sequence similarity, many ECs were predicted to have structural similarity to avirulence proteins from other plant-pathogenic fungi, including members of the MAX, LARS, ToxA and FOLD effector families. In addition, several other ECs, including an EC family with sequence similarity to the AvrLm6 avirulence effector from Leptosphaeria maculans, were predicted to adopt a KP6-like fold. Thus, proteins with a KP6-like fold represent another structural family of effectors shared among plant-pathogenic fungi. CONCLUSIONS: Our study reveals the transcriptomic profile underpinning subcuticular growth by V. inaequalis and provides an enriched list of ECs that can be investigated for roles in virulence and avirulence. Furthermore, our study supports the idea that numerous sequence-unrelated effectors across plant-pathogenic fungi share common structural folds. In doing so, our study gives weight to the hypothesis that many fungal effectors evolved from ancestral genes through duplication, followed by sequence diversification, to produce sequence-unrelated but structurally similar proteins.


Assuntos
Ascomicetos , Malus , Ascomicetos/genética , Doenças das Plantas/microbiologia , Fungos do Gênero Venturia , Malus/genética , Malus/microbiologia
5.
Ind Eng Chem Res ; 60(44): 15999-16010, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34949902

RESUMO

This work reports initial results on the effect of low concentrations (ppm level) of a stabilizing agent (2,6-di-tert-butyl-4-methylphenol, BHT) present in an off-the-shelf solvent on the catalyst performance for the hydrogenolysis of γ-butyrolactone over Cu-ZnO-based catalysts. Tetrahydrofuran (THF) was employed as an alternative solvent in the hydrogenolysis of γ-butyrolactone. It was found that the Cu-ZnO catalyst performance using a reference solvent (1,4-dioxane) was good, meaning that the equilibrium conversion was achieved in 240 min, while a zero conversion was found when employing tetrahydrofuran. The deactivation was studied in more detail, arriving at the preliminary conclusion that one phenomenon seems to play a role: the poisoning effect of a solvent additive present at the ppm level (BHT) that appears to inhibit the reaction completely over a Cu-ZnO catalyst. The BHT effect was also visible over a commercial Cu-ZnO-MgO-Al2O3 catalyst but less severe than that over the Cu-ZnO catalyst. Hence, the commercial catalyst is more tolerant to the solvent additive, probably due to the higher surface area. The study illustrates the importance of solvent choice and purification for applications such as three-phase-catalyzed reactions to achieve optimal performance.

6.
BMC Oral Health ; 20(1): 273, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028292

RESUMO

BACKGROUND: The insertion of dental implants in the atrophic posterior maxilla can be a challenge. One option is to modify the residual native bone in preparation for proper, prosthetically-driven implant placement. The procedure presented in this study is called Navigated Antral Bone Expansion (N.A.B.E). This procedure employs the use of a navigation system to plan and guide the initial pilot drilling, bone expansion, final site preparation, and implant insertion. The aim of this study was to compare the distance between the alveolar ridge and the sinus floor measured before and after the surgery performed using the N.A.B.E. METHODS: Thirty-seven partially edentulous patients who were candidates for implant supported restoration in the posterior maxilla, with a bone height ranging from 4 to 7 mm were enrolled. The N.A.B.E procedure was used to increase the bone height. Paired-samples t-test evaluated the distance between the alveolar ridge and the sinus floor measured before and after surgery. The occurrence of post-surgical complications, and the angular deviation between the planned osteotomy and the actual placed implant trajectories were evaluated. RESULTS: Out of the 37 consecutive patients enrolled in the study, 35 were considered in the data analyses. Patients' bone height after surgery compared to the bone height before surgery showed a statistically significant increase (p < .0005) of 3.96 mm (95% CI, 3.62 mm to 4.30 mm). No post-operative complications were observed in the 35 patients. The mean angular deviation between the planned osteotomy trajectory and the placed implant trajectory ranged between 12.700 to 34.900 (mean 25.170 ± 5.100). CONCLUSIONS: This study provides evidence that N.A.B.E. technique is able to provide a significant bone increase, and could be considered an alternative method to the management of the atrophic posterior maxilla with a minimally invasive approach.


Assuntos
Aumento do Rebordo Alveolar , Implantes Dentários , Levantamento do Assoalho do Seio Maxilar , Arginina/análogos & derivados , Implantação Dentária Endóssea , Falha de Restauração Dentária , Seguimentos , Humanos , Maxila/cirurgia , Estudos Prospectivos , Resultado do Tratamento
7.
Chem Commun (Camb) ; 51(81): 14992-5, 2015 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-26311021

RESUMO

Herein we show that species generated upon reaction of α-[Fe(CF3SO3)2(BPMCN)] (BPMCN = N,N'-bis(2-pyridylmethyl)-trans-1,2-diaminocyclohexane) with H2O2 (putatively [Fe(V)(O)(OH)(BPMCN)]) is able to efficiently oxidize H2 to H2O even in the presence of organic substrates, while species formed in the presence of acetic acid (putatively [Fe(V)(O)(OAc)(BPMCN)]) prefer organic substrate oxidation over H2 activation. Mechanistic implications have been analysed with the aid of computational methods.


Assuntos
Peróxido de Hidrogênio/química , Hidrogênio/química , Compostos de Ferro/química , Água/química , Heme , Conformação Molecular , Oxirredução
8.
J Prosthet Dent ; 107(3): 151-7, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22385690

RESUMO

Residual excess cement (REC) is a common complication of cement-retained prostheses and has been linked to periimplant disease. Removal of the cement residue may result in resolution of the issue if addressed early in the disease process. However, this is dependent upon the ability to locate and adequately remove the foreign material. This series of patient scenarios describes the ability to detect REC by using dental radiography. Characteristics related to cements and flow patterns specific to implants are addressed.


Assuntos
Cimentação/efeitos adversos , Coroas , Cimentos Dentários/efeitos adversos , Prótese Dentária Fixada por Implante , Radiografia Interproximal , Idoso , Desbridamento , Fístula Dentária/etiologia , Projeto do Implante Dentário-Pivô , Implantes Dentários para Um Único Dente , Restauração Dentária Temporária , Raspagem Dentária/instrumentação , Feminino , Seguimentos , Corpos Estranhos/complicações , Cimentos de Ionômeros de Vidro/efeitos adversos , Humanos , Incisivo , Masculino , Mandíbula/cirurgia , Maxila/cirurgia , Pessoa de Meia-Idade , Dente Molar , Peri-Implantite/etiologia , Cimentos de Resina/efeitos adversos , Retalhos Cirúrgicos , Cimento de Óxido de Zinco e Eugenol/efeitos adversos
11.
Rev. argent. infectol ; 9(5): 19-24, 1996. tab, graf
Artigo em Espanhol | BINACIS | ID: bin-17470

RESUMO

Se analizó un grupo de pacientes que concurrieron a los consultorios externos de un hospital de enfermedades infecciosas, presentando como síntoma principal adenopatías regionales o generalizadas. El 78 se hallaban entre los 20 y 40 años de edad, el 56 fue de evolución aguda, predominando netamente la distribución regional, en especial la localización cervical. Se llegó al diagnóstico final en el 80 de los casos. En base a la experiencia realizada, se presenta un algoritmo diagnóstico y se establecen pautas de conducta ante este síndrome (AU)


Assuntos
Humanos , Linfadenite/classificação , Linfadenite/diagnóstico , Diagnóstico Clínico , Argentina
14.
Rev. argent. infectol ; 9(5): 19-24, 1996. tab, graf
Artigo em Espanhol | LILACS | ID: lil-223398

RESUMO

Se analizó un grupo de pacientes que concurrieron a los consultorios externos de un hospital de enfermedades infecciosas, presentando como síntoma principal adenopatías regionales o generalizadas. El 78 se hallaban entre los 20 y 40 años de edad, el 56 fue de evolución aguda, predominando netamente la distribución regional, en especial la localización cervical. Se llegó al diagnóstico final en el 80 de los casos. En base a la experiencia realizada, se presenta un algoritmo diagnóstico y se establecen pautas de conducta ante este síndrome


Assuntos
Humanos , Diagnóstico Clínico , Linfadenite/classificação , Linfadenite/diagnóstico , Argentina
15.
Medicina [B.Aires] ; 55(4): 337-40, 1995. ilus, tab
Artigo em Espanhol | BINACIS | ID: bin-23054

RESUMO

This paper presents the fourth case reported on the association of primary bronchial actinomycosis and foreign body. The pathogenesis of this rare association has been linked to the low respiratory tract and a foreign body (chicken bone); it depends on its characteristics and how long it has remained lodged into the bronchial tree. The diagnosis of this case was very difficult and late. Several endoscopy procedures were required in order to detect it. Our patient has been treated successfully with parenteral penicillin in association with an original bronchoscopic procedure using a laser technique to find the foreign body and take it out of the respiratory tract. We consider that it is necessary to remember this association in every patient who suffers from recurrent pneumonia, in those who are at risk of foreign body aspiration and when the presence of an endobronchial mass is suspected.(AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Actinomicose/etiologia , Brônquios , Broncopatias/microbiologia , Corpos Estranhos/complicações , Lasers , Diagnóstico Diferencial , Actinomicose/diagnóstico , Actinomicose/terapia , Broncopatias/cirurgia , Broncopatias/patologia , Broncopatias/diagnóstico por imagem , Corpos Estranhos/cirurgia , Corpos Estranhos/diagnóstico
16.
Medicina (B.Aires) ; 55(4): 337-40, 1995. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-161637

RESUMO

This paper presents the fourth case reported on the association of primary bronchial actinomycosis and foreign body. The pathogenesis of this rare association has been linked to the low respiratory tract and a foreign body (chicken bone); it depends on its characteristics and how long it has remained lodged into the bronchial tree. The diagnosis of this case was very difficult and late. Several endoscopy procedures were required in order to detect it. Our patient has been treated successfully with parenteral penicillin in association with an original bronchoscopic procedure using a laser technique to find the foreign body and take it out of the respiratory tract. We consider that it is necessary to remember this association in every patient who suffers from recurrent pneumonia, in those who are at risk of foreign body aspiration and when the presence of an endobronchial mass is suspected.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Actinomicose/etiologia , Brônquios , Broncopatias/microbiologia , Corpos Estranhos/complicações , Actinomicose/diagnóstico , Actinomicose/terapia , Broncopatias , Broncopatias/patologia , Broncopatias/cirurgia , Diagnóstico Diferencial , Corpos Estranhos/diagnóstico , Corpos Estranhos/cirurgia , Lasers
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