RESUMEN
Fusarium wilt of banana (FWB), caused by a suite of Fusarium fungi, is among the most devastating plant diseases. The iconic FWB epidemic in the previous century lasted decades and was caused by so-called Race 1 strains that wiped out the dominant 'Gros Michel' banana plantations across Central America. Eventually, it was stopped because the Race 1-resistant 'Cavendish' banana variety replaced 'Gros Michel', which dominates global production (>50%) and trade (>95%). However, presently, the so-called Tropical Race 4 (TR4) threatens plantations of 'Cavendish' and many other banana varieties around the globe. Prevention is the first line of defense against the spread of TR4. Therefore, many disinfection units are installed to prevent the entry of TR4 in banana plantations. These foot and tire baths are filled with disinfectants, but limited knowledge is available on their efficacy. In this project, we evaluated 13 disinfectants commonly used in the Philippines. Our results show that the efficacy of these products depends on the type of fungal spores, the exposure time, and the replenishment frequency of the disinfection units. The resting spores of TR4 were resistant to all but one - unfortunately corrosive - disinfectant. Furthermore, we show that the actual contact time with disinfectants was far below the thresholds determined in laboratory experiments. Finally, muddy disinfection units reduced the efficacy of disinfectants. Taken together, we conclude that practices are inadequate to prevent the dissemination of TR4.
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Desinfectantes , Fusarium , Musa , Desinfectantes/farmacología , Musa/microbiología , Filipinas , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & controlRESUMEN
Blast disease is a notorious fungal disease leading to dramatic yield losses on major food crops such as rice and wheat. The causal agent, Pyricularia oryzae, encompasses different lineages, each having a different host range. Host shifts are suspected to have occurred in this species from Setaria spp. to rice and from Lolium spp. to wheat. The emergence of blast disease on maize in Iran was observed for the first time in the north of the country in 2012. We later identified blast disease in two additional regions of Iran: Gilan in 2013 and Golestan in 2016. Epidemics on the weed barnyard grass (Echinochloa spp.) were also observed in the same maize fields. Here, we showed that P. oryzae is the causal agent of this disease on both hosts. Pathogenicity assays in the greenhouse revealed that strains from maize can infect barnyard grass and conversely. However, genotyping with simple sequence repeat markers and comparative genomics showed that strains causing field epidemics on maize and on barnyard grass are different, although they belong to the same previously undescribed clade of P. oryzae. Phylogenetic analyses including these strains and a maize strain collected in Gabon in 1985 revealed two independent host-range expansion events from barnyard grass to maize. Comparative genomics between maize and barnyard grass strains revealed the presence or absence of five candidate genes associated with host specificity on maize, with the deletion of a small genomic region possibly responsible for adaptation to maize. This recent emergence of P. oryzae on maize provides a case study to understand host range expansion. Epidemics on maize raise concerns about potential yield losses on this crop in Iran and potential geographic expansion of the disease.
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Echinochloa , Magnaporthe , Oryza , Ascomicetos , Irán , Filogenia , Enfermedades de las Plantas , Zea maysRESUMEN
Fungal protoplast fusion is an approach to introduce novel characteristics into industrially important strains. Cellulases, essential enzymes with a wide range of biotechnological applications, are produced by many species of the filamentous fungi Trichoderma. In this study, a collection of 60 natural isolates were screened for Avicel and carboxymethyl cellulose degradation, and two cellulase producers of Trichoderma virens and Trichoderma harzianum were used for protoplast fusion. One of the resulting hybrids with improved cellulase activity, C1-3, was fused with the hyperproducer Trichoderma reesei Rut-C30. A new selected hybrid, F7, was increased in cellulase activity 1.8 and 5 times in comparison with Rut-C30 and C1-3, respectively. The increases in enzyme activity correlated with an upregulation of the cellulolytic genes cbh1, cbh2, egl3, and bgl1 in the parents. The amount of mRNA of cbh1 and cbh2 in F7 resembled that of Rut-C30 while the bgl1 mRNA level was similar to that of C1-3. AFLP (amplified fragment length polymorphism) fingerprinting and GC-MS (gas chromatography - mass spectrometry) analysis represented variations in parental strains and fusants. In conclusion, the results demonstrate that a 3-interspecific hybrid strain was isolated, with improved characteristics for cellulase degradation and showing genetic polymorphisms and differences in the volatile profile, suggesting reorganizations at the genetic level.
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Celulasa/biosíntesis , Hypocreales/enzimología , Protoplastos/metabolismo , Trichoderma/enzimología , Trichoderma/genética , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Celulosa/metabolismo , Regulación Fúngica de la Expresión Génica , Hypocrea/enzimología , Hypocrea/genética , Hypocreales/genética , Microbiología Industrial , Polimorfismo Genético , ARN de Hongos/genética , ARN Mensajero/genéticaRESUMEN
QUESTION: A few patients have previously presented to my clinic with palpable purpura, joint inflammation, and severe abdominal pain characteristic of Henoch-Schönlein purpura (HSP). Considering that renal injury is the primary long-term complication of HSP, are corticosteroids effective in preventing or treating renal disease in children with HSP? ANSWER: Henoch-Schönlein purpura is self-limiting in 94% of children, but permanent renal injury is reported in one-fifth of children with nephritic or nephrotic features. Corticosteroids have been considered as candidates for preventing and treating renal involvement in HSP. There is a moderate level of evidence to suggest corticosteroids are not effective in preventing renal involvement in HSP. However, based on low-level evidence and similarities with primary immunoglobulin A nephropathy, experts recommend corticosteroids in treating renal involvement in HSP to prevent long-term kidney injury. Dose and duration of therapy should be carefully considered in consultation with a pediatric nephrologist.
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Corticoesteroides/uso terapéutico , Vasculitis por IgA/tratamiento farmacológico , Enfermedades Renales/prevención & control , Dolor Abdominal , Corticoesteroides/efectos adversos , Niño , Preescolar , Femenino , Humanos , Vasculitis por IgA/complicaciones , MasculinoRESUMEN
The dimorphic fungal pathogen, Zymoseptoria tritici undergoes discrete developmental changes to complete its life cycle on wheat. Molecular mechanisms underlying morphogenesis during infection process of Z. tritici are poorly understood. In this study, we have investigated the role of ZtVf1 gene encoding a transcription factor belonging to C2-H2 subfamily. In planta assays revealed that ZtVf1 is required for virulence. Reduced necrotic lesions and low pycnidia density within the lesions resulted in significantly reduced virulence of ZtVf1 mutants. Cytological analysis showed that the impaired virulence of ZtVf1 mutants attributed to reduced penetration and colonization along with hampered pycnidia differentiation. In vitro phenotyping showed that ZtVf1 deletion affects hyphal branching and biomass production suggesting that the reduced tissue colonization by the ZtVf1 mutant might be due to lower hyphal branching and less fungal biomass production. In addition, the majority of infected substomatal cavities by the ZtVf1 mutant filled with compacted mycelia mat that did not differentiate to mature pycnidia indicating that the impaired melanization negatively affected pycnidia formation and maturation. The ZtVf1 might target multiple genes belonging to different cellular processes whose identification is of eminent interest to increase our understanding of this pathosystem. Overall, the data provided in this study indicates that attenuated pathogenicity of ZtVf1 mutant is due to involvement of this gene in the regulation of both early and late stages of infection.
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Ascomicetos/fisiología , Factores de Transcripción/fisiología , Triticum/microbiología , Ascomicetos/genética , Ascomicetos/patogenicidad , Regulación Fúngica de la Expresión Génica , Genes Fúngicos , Mutación , Filogenia , Enfermedades de las Plantas/microbiología , Virulencia/genéticaRESUMEN
Genetic manipulation of fungi requires quick, low-cost, efficient, high-throughput and molecular tools. In this paper, we report 22 entry constructs as new molecular tools based on the Gateway technology facilitating rapid construction of binary vectors that can be used for functional analysis of genes in fungi. The entry vectors for single, double or triple gene-deletion mutants were developed using hygromycin, geneticin and nourseothricin resistance genes as selection markers. Furthermore, entry vectors containing green fluorescent (GFP) or red fluorescent (RFP) in combination with hygromycin, geneticin or nourseothricin selection markers were generated. The latter vectors provide the possibility of gene deletion and simultaneous labelling of the fungal transformants with GFP or RFP reporter genes. The applicability of a number of entry vectors was validated in Zymoseptoria tritici, an important fungal wheat pathogen.
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Hongos/genética , Expresión Génica , Marcación de Gen/métodos , Vectores Genéticos , Genética Microbiana/métodos , Biología Molecular/métodos , Plantas/microbiología , Farmacorresistencia Fúngica , Hongos/patogenicidad , Hongos/fisiología , Genes Fúngicos , Proteínas Luminiscentes/análisis , Proteínas Luminiscentes/genética , Selección Genética , Coloración y Etiquetado/métodos , Transformación GenéticaRESUMEN
Zymoseptoria tritici is an economically important pathogen of wheat. However, the molecular basis of pathogenicity on wheat is still poorly understood. Here, we present a global survey of the proteins secreted by this fungus in the apoplast of resistant (cv. Shafir) and susceptible (cv. Obelisk) wheat cultivars after inoculation with reference Z. tritici strain IPO323. The fungal proteins present in apoplastic fluids were analyzed by gel electrophoresis and by data-independent acquisition liquid chromatography/mass spectrometry (LC/MS(E)) combined with data-dependent acquisition LC-MS/MS. Subsequent mapping mass spectrometry-derived peptide sequence data against the genome sequence of strain IPO323 identified 665 peptides in the MS(E) and 93 in the LC-MS/MS mode that matched to 85 proteins. The identified fungal proteins, including cell-wall degrading enzymes and proteases, might function in pathogenicity, but the functions of many remain unknown. Most fungal proteins accumulated in cv. Obelisk at the onset of necrotrophy. This inventory provides an excellent basis for future detailed studies on the role of these genes and their encoded proteins during pathogenesis in wheat.
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Ascomicetos/química , Proteínas Fúngicas/análisis , Enfermedades de las Plantas/microbiología , Proteoma/análisis , Triticum/microbiología , Ascomicetos/aislamiento & purificación , Cromatografía Liquida , Electroforesis , Espectrometría de Masas , Espectrometría de Masas en TándemRESUMEN
Culture filtrates (CFs) of the fungal wheat pathogen Zymoseptoria tritici were assayed for necrosis-inducing activity after infiltration in leaves of various wheat cultivars. Active fractions were partially purified and characterized. The necrosis-inducing factors in CFs are proteinaceous, heat stable and their necrosis-inducing activity is temperature and light dependent. The in planta activity of CFs was tested by a time series of proteinase K (PK) co-infiltrations, which was unable to affect activity 30min after CF infiltrations. This suggests that the necrosis inducing proteins (NIPs) are either absent from the apoplast and likely actively transported into mesophyll cells or protected from the protease by association with a receptor. Alternatively, plant cell death signaling pathways might be fully engaged during the first 30min and cannot be reversed even after PK treatment. Further fractionation of the CFs with the highest necrosis-inducing activity involved fast performance liquid chromatography, SDS-PAGE and mass spectrometry. This revealed that most of the proteins present in the fractions have not been described before. The two most prominent ZtNIP encoding candidates were heterologously expressed in Pichia pastoris and subsequent infiltration assays showed their differential activity in a range of wheat cultivars.
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Ascomicetos/química , Proteínas Fúngicas/análisis , Necrosis/microbiología , Enfermedades de las Plantas/microbiología , Triticum/microbiología , Factores de Virulencia/análisis , Cromatografía Liquida , Electroforesis en Gel de Poliacrilamida , Proteínas Fúngicas/química , Luz , Espectrometría de Masas , Estabilidad Proteica , Temperatura , Factores de Virulencia/químicaRESUMEN
Adequate sleep is an important component of cardiovascular health. Due to circadian misalignment and irregular shifts, inadequate sleep is common in shift workers. Adverse consequences include daytime sleepiness, decreased cognitive performance, increased sympathetic tone, inflammation, impaired glucose tolerance, and altered leptin and ghrelin levels. When circadian adjustment has not occurred, daytime sleepers often experience decreased sleep duration and increased wakefulness during displaced sleep; additionally, skipping sleep is common in shift workers, further contributing to sleep deprivation. Habitual decreased sleep duration and physiological changes contribute to obesity, diabetes, hypertension, and increased cardiovascular disease risk in shift workers. Shift workers with obstructive sleep apnea (OSA), the most common sleep-related breathing disorder, can experience more frequent sleep disruptions than non-shift workers with OSA. Furthermore, shift work-induced circadian misalignment may potentiate cardiometabolic risk in OSA patients through autonomic nervous system dysfunction and other mechanisms.
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Apnea Obstructiva del Sueño , Trastornos del Sueño del Ritmo Circadiano , Humanos , Tolerancia al Trabajo Programado/fisiología , Ritmo Circadiano/fisiología , Sueño/fisiología , Privación de SueñoRESUMEN
A total of 265 fungal individuals were isolated from soils exposed to heavy oil spills in the Yadavaran oil field in Iran to discover indigenous fungal species with a high potential to biodegrade petroleum hydrocarbon pollutants. Morphological and molecular identification of obtained fungal species led to their assignment into 16 genera and 25 species. Alternaria spp. (78%), Fusarium spp. (5%), and Cladosporium spp. (4%) were the most common genera, along with Penicillium spp., Neocamarosporium spp., Epicoccum sp., Kotlabaea sp., Aspergillus sp., Mortierella sp., and Pleurotus sp. A preliminary screening using the DCPIP indicator revealed that approximately 35% of isolates from Alternaria, Epicoccum, Neocamarosporium, Cladosporium, Fusarium, Stachybotrys, Penicillium, and Stemphylium demonstrated promising tolerance to crude oil. The best-performing isolates (12 fungal individuals) were further investigated for their capacity to mineralize a mixture of four polycyclic aromatic hydrocarbons (PAH) for 47 days, quantified by GC-MS. Eventually, two top-performing isolates, namely 5c-12 (Alternaria tenuissima) and 3b-1 (Epicoccum nigrum), were applied to petroleum-contaminated soil. The GC-MS analysis showed that 60 days after inoculation, these isolates successfully degraded more than 70% of the long-chain hydrocarbons in the soil, including C8-C16 n-alkanes, C36 n-alkane, and Pristane. This study introduces two fungal species (5c-12 and 3b-1) with high potential for biodegrading petroleum compounds and PAHs, offering promising prospects for the decontamination of oil-contaminated soil.
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Penicillium , Petróleo , Hidrocarburos Policíclicos Aromáticos , Contaminantes del Suelo , Humanos , Hidrocarburos Policíclicos Aromáticos/análisis , Petróleo/metabolismo , Irán , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Hidrocarburos/análisis , Alcanos/metabolismo , Biodegradación Ambiental , Penicillium/metabolismo , SueloRESUMEN
Adequate sleep is an important pillar of physical and mental health. Sleep deficiency, resulting from short sleep or suboptimal sleep quality, is highly prevalent in modern society. Occupation, social demands, psychiatric disorders, physical disorders, and sleep disorders are some of the contributing factors to sleep deficiency. Some populations are at increased risk of sleep deficiency based on ethnicity, age, marital status, sex, and hospitalization. Sleep deficiency influences cognition, alertness, mood, behavior, diabetes, cardiovascular health, renal function, immune system, and respiratory physiology. This review summarizes the epidemiology and effects of sleep deficiency.
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Trastornos del Sueño-Vigilia , Sueño , Humanos , Sueño/fisiología , Trastornos del Sueño-Vigilia/epidemiología , Trastornos del Sueño-Vigilia/etiologíaRESUMEN
This study offers new perspectives on the biochemical and physiological changes that occur in wheat following a gene-for-gene interaction with the fungal pathogen Zymoseptoria tritici. The Z. tritici isolate IPO323, carries AvrStb6, while ΔAvrStb6#33, lacks AvrStb6. The wheat cultivar (cv.) Shafir, bears the corresponding resistance gene Stb6. Inoculation of cv. Shafir with these isolates results in two contrasted phenotypes, offering a unique opportunity to study the immune response caused by the recognition of AvrStb6 by Stb6. We employed a variety of methodologies to dissect the physiological and biochemical events altered in cv. Shafir, as a result of the AvrStb6-Stb6 interaction. Comparative analysis of stomatal conductance demonstrated that AvrStb6-Stb6 mediates transient stomatal closures to restrict the penetration of Zymoseptoria tritici. Tracking photosynthetic functionality through chlorophyll fluorescence imaging analysis demonstrated that AvrStb6-Stb6 retains the functionality of photosynthesis apparatus by promoting Non-Photochemical Quenching (NPQ). Furthermore, the PlantCV image analysis tool was used to compare the H2O2 accumulation and incidence of cell death (2, 4, 8, 12, 16, and 21 dpi), over Z. tritici infection. Finally, our research shows that the AvrStb6-Stb6 interaction coordinates the expression and activity of antioxidant enzymes, both enzymatic and non-enzymatic, to counteract oxidative stress. In conclusion, the Stb6-AvrStb6 interaction in the Z. tritici-wheat pathosystem triggers transient stomatal closure and maintains photosynthesis while regulating oxidative stress.
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In this clinical guidelines article, we first include a brief review of the epidemiology, pathogenesis, clinical diagnoses, and scoring-scales for pediatric atopic dermatitis (AD). We then offer a set of pharmacologic treatment guidelines for infants and toddlers (<2 years), children (2-12 years), and adolescents (>12 years). We recommend irritant avoidance and liberal emollient usage as the cornerstone of treatment in all age-groups. In infants <2 years, we recommend topical corticosteroids as first-line medication-based therapy. In infants as young as 3 months, pimecrolimus, a topical calcineurin inhibitor, may also be used. As a last resort in patients <2 years, non-traditional therapies, such as the Aron regime, may be a safer option for refractory or resistant AD before off- label medications are considered. In children and adolescents >2 years, topical corticosteroids are still considered first-line therapies, but there is sufficient safety data to utilize topical calcineurin inhibitors and topical PDE4 inhibitors as well. In children ages 2-12 years whose atopic dermatitis fails to respond to prior treatments, oral systemic immunosuppressants can be used. For adolescents >12, the biologic, dupilumab, is an additional therapeutic option. A trial of phototherapy may also be utilized in children, particularly in adolescents >12 years, if they have access to treatment. Although not currently approved for the treatment of AD, Janus-kinase (JAK) inhibitors represent a promising new class of biologics with recently completed phase III clinical trials (JADE-- MONO1/2).
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Dermatitis Atópica , Fármacos Dermatológicos , Eccema , Adolescente , Inhibidores de la Calcineurina/uso terapéutico , Niño , Preescolar , Dermatitis Atópica/diagnóstico , Dermatitis Atópica/tratamiento farmacológico , Fármacos Dermatológicos/uso terapéutico , Humanos , InmunosupresoresRESUMEN
Zymoseptoria tritici is one of the most economically destructive wheat diseases all over the world and is a model fungal plant pathogen within the ascomycetes. In this study, the instrumental role of the ZtRlm1 gene encoding a MADS-box transcription factor (TF) in the infection process of Z. tritici was functionally characterized as these proteins play critical roles in the global gene regulation required for various developmental and physiological processes. Our infection assays showed that ZtRlm1 mutants were attenuated in disease development as a 30 and 90% reduction in chloro-necrotic lesions and pycnidia formation, respectively, were observed in plants inoculated with ZtRlm1 mutant strains demonstrating that ZtRlm1 is a crucial factor playing a significant role in the late stage of infection corresponding with pycnidial formation. Our expression analysis demonstrated that the transcript level of ZtRlm1 is induced at 2 and 20 days post-inoculation, coinciding with pycnidial sporulation. In addition, microscopic analyses showed that branch intensity and biomass production were significantly reduced, indicating that impaired pycnidia formation is a result of impaired differentiation and biomass production in the ZtRlm1 mutants. Furthermore, melanization, a phenomenon required for fruiting body formation, was significantly hampered in ZtRlm1 mutants as they were not melanized under all tested temperature and media conditions. Overall, our data showed that impaired disease development of the ZtRlm1 mutants is mainly due to the significant impact of ZtRlm1 in different cellular processes, including differentiation, branching, fungal biomass production, and melanization, in which identification of downstream genes are of interest to increase our understanding of this pathosystem.
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A high affinity and selectivity DNA aptamer for aflatoxin B1 (AFB1) was designed through Genetic Algorithm (GA) based in silico maturation (ISM) strategy. The sequence of a known AFB1 aptamer (Patent: PCT/CA2010/001292, Apt1) applied as a probe in many aptasensors was modified using seven GA rounds to generate an initial library and three different generations of ss DNA oligonucleotides as new candidate aptamers. Molecular docking methodology was used to screen and analyze the best aptamer-AFB1 complexes. Also, a new pipeline was proposed to faithfully predict the tertiary structure of all single stranded DNA sequences. By the second generation, aptamer Apt1 sequence was optimized in the local search space and five aptamers including F20, g12, C52, C32 and H1 were identified as the best aptamers for AFB1. The selected aptamers were applied as probes in an unmodified gold nanoparticles-based aptasensor to evaluate their binding affinity to AFB1 and their selectivity against other mycotoxins (aflatoxins B2, G1, G2, M1, ochratoxin A and zearalenone). In addition, a novel direct fluorescent anisotropy aptamer assay was developed to confirm the binding interaction of the selected aptamers over AFB1. The ISM allowed the identification of an aptamer, F20, with up to 9.4 and 2 fold improvement in affinity and selectivity compared to the parent aptamer, respectively.
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Aflatoxina B1/análisis , Aptámeros de Nucleótidos/química , Técnicas Biosensibles , Oro/química , Nanopartículas del Metal/química , Simulación del Acoplamiento MolecularRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMEN
Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB) disease of wheat. Z. tritici is an apoplastic fungal pathogen, which does not penetrate plant cells at any stage of infection, and has a long initial period of symptomless leaf colonisation. During this phase it is unclear to what extent the fungus can access host plant nutrients or communicate with plant cells. Several important primary and secondary metabolite pathways in fungi are regulated by the post-translational activator phosphopantetheinyl transferase (Ppt) which provides an essential co-factor for lysine biosynthesis and the activities of non-ribosomal peptide synthases (NRPS) and polyketide synthases (PKS). To investigate the relative importance of lysine biosynthesis, NRPS-based siderophore production and PKS-based DHN melanin biosynthesis, we generated deletion mutants of ZtPpt. The ∆ZtPpt strains were auxotrophic for lysine and iron, non-melanised and non-pathogenic on wheat. Deletion of the three target genes likely affected by ZtPpt loss of function (Aar- lysine; Nrps1-siderophore and Pks1- melanin), highlighted that lysine auxotrophy was the main contributing factor for loss of virulence, with no reduction caused by loss of siderophore production or melanisation. This reveals Ppt, and the lysine biosynthesis pathway, as potential targets for fungicides effective against Z. tritici.
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Ascomicetos/patogenicidad , Proteínas Bacterianas/metabolismo , Lisina/biosíntesis , Melaninas/metabolismo , Enfermedades de las Plantas/microbiología , Sideróforos/metabolismo , Transferasas (Grupos de Otros Fosfatos Sustitutos)/metabolismo , Triticum/microbiología , Virulencia , Proteínas Fúngicas/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Hojas de la Planta/microbiología , Esporas Fúngicas/metabolismo , Triticum/crecimiento & desarrollo , Triticum/metabolismoRESUMEN
Host resistance and fungicide treatments are cornerstones of plant-disease control. Here, we show that these treatments allow sex and modulate parenthood in the fungal wheat pathogen Zymoseptoria tritici. We demonstrate that the Z. tritici-wheat interaction complies with the gene-for-gene model by identifying the effector AvrStb6, which is recognized by the wheat resistance protein Stb6. Recognition triggers host resistance, thus implying removal of avirulent strains from pathogen populations. However, Z. tritici crosses on wheat show that sex occurs even with an avirulent parent, and avirulence alleles are thereby retained in subsequent populations. Crossing fungicide-sensitive and fungicide-resistant isolates under fungicide pressure results in a rapid increase in resistance-allele frequency. Isolates under selection always act as male donors, and thus disease control modulates parenthood. Modeling these observations for agricultural and natural environments reveals extended durability of host resistance and rapid emergence of fungicide resistance. Therefore, fungal sex has major implications for disease control.
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Ascomicetos/patogenicidad , Farmacorresistencia Fúngica/genética , Polinización , Proteínas Quinasas/genética , Estrés Fisiológico , Estrobilurinas/farmacología , Triticum/genética , Agricultura , Ascomicetos/efectos de los fármacos , Mapeo Cromosómico , Cromosomas de las Plantas , Epistasis Genética , Fungicidas Industriales/farmacología , Interacciones Huésped-Patógeno/efectos de los fármacos , Interacciones Huésped-Patógeno/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Polinización/efectos de los fármacos , Polinización/genética , Proteínas Quinasas/fisiología , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/genética , Triticum/fisiologíaRESUMEN
Recent advances in genetic and molecular technologies gradually paved the way for the transition from traditional fungal karyotyping to more comprehensive chromosome biology studies. Extensive chromosomal polymorphisms largely resulting from chromosomal rearrangements (CRs) are widely documented in fungal genomes. These extraordinary CRs in fungi generate substantial genome plasticity compared to other eukaryotic organisms. Here, we review the most recent findings on fungal CRs and their underlying mechanisms and discuss the functional consequences of CRs for adaptation, fungal evolution, host range, and pathogenicity of fungal plant pathogens in the context of chromosome biology. In addition to a complement of permanent chromosomes called core chromosomes, the genomes of many fungal pathogens comprise distinct unstable chromosomes called dispensable chromosomes (DCs) that also contribute to chromosome polymorphisms. Compared to the core chromosomes, the structural features of DCs usually differ for gene density, GC content, housekeeping genes, and recombination frequency. Despite their dispensability for normal growth and development, DCs have important biological roles with respect to pathogenicity in some fungi but not in others. Therefore, their evolutionary origin is also reviewed in relation to overall fungal physiology and pathogenicity.
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Cromosomas Fúngicos/genética , Hongos/genética , Hongos/patogenicidad , Cariotipo , Enfermedades de las Plantas/microbiología , Plantas/microbiología , Evolución Molecular , Reordenamiento Génico , Genoma FúngicoRESUMEN
STUDY OBJECTIVE: Rapid repeat adolescent pregnancy is a significant public health concern. An effective and practical means of decreasing unintended second adolescent pregnancies needs to be identified. The objective of this study is to determine if early initiation of contraception, and in particular long acting reversible contraception (LARC), decreases rapid repeat pregnancy among first time adolescent mothers. DESIGN: Retrospective cohort study. SETTING: Urban teaching hospital. PARTICIPANTS: 340 first-time adolescent mothers age ≤ 19. INTERVENTIONS: None, study was retrospective. MAIN OUTCOME MEASURES: Repeat pregnancy within 2 years. RESULTS: 340 first time adolescent mothers with a documented follow-up time of 2 years had a repeat pregnancy rate of 35%. Average time from delivery to repeat pregnancy was 9.9 ± 6.4 months. Logistic regression analysis comparing adolescents with and without repeat pregnancy revealed that leaving the hospital postpartum without initiating any contraception was associated with significant increase risk of repeat pregnancy (OR = 2.447, 95% CI 1.326-4.515). Follow-up within 8 weeks postpartum was associated with lower chance of repeat pregnancy (OR = 0.322, 95% CI 0.172-0.603). Initiation of a LARC method (either an intrauterine device or etonogestrel subdermal implant) by 8 weeks postpartum was also associated with decreased chance of rapid repeat pregnancy (OR = 0.118, 95% CI 0.035-0.397). CONCLUSION: Adolescent mothers who initiate a LARC method within 8 weeks of delivery are less likely to have a repeat pregnancy within 2 years than those who choose other methods or no method. First time adolescent mothers should be counseled about this advantage of using LARC.