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1.
PLoS One ; 15(7): e0236191, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673365

RESUMO

Paclitaxel is an effective natural-source chemotherapeutic agent commonly applied to treat a vast range of cancers. In vitro Corylus avellana culture has been reported as a promising and inexpensive system for paclitaxel production. Fungal elicitors have been made known as the most efficient strategy for the biosynthesis induction of secondary metabolites in plant in vitro culture. In this research, C. avellana cell suspension culture (CSC) was exposed to cell extract (CE) and culture filtrate (CF) derived from Camarosporomyces flavigenus, either individually or combined treatment, in mid and late log phase. There is no report on the use of whole fungal elicitors (the combined treatment of CE and CF) for the elicitation of secondary metabolite biosynthesis in plant in vitro culture. The combined treatment of CE and CF significantly led to more paclitaxel biosynthesis and secretion than the individual use of them. Also, multivariate statistical approaches including stepwise regression (SR), ordinary least squares regression (OLSR), principal component regression (PCR) and partial least squares regression (PLSR) were used to model and predict paclitaxel biosynthesis and secretion. Based on value account for (VAF), root mean square error (RMSE), coefficient of determination (R2), mean absolute percentage error (MAPE) and relative percent difference (RPD) can be concluded that mentioned regression models effectively worked only for modeling and predicting extracellular paclitaxel portion in C. avellana cell culture.


Assuntos
Ascomicetos/fisiologia , Corylus/citologia , Paclitaxel/biossíntese , Ascomicetos/química , Ascomicetos/isolamento & purificação , Técnicas de Cultura de Células/métodos , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Corylus/metabolismo , Corylus/microbiologia , Análise dos Mínimos Quadrados , Modelos Biológicos , Paclitaxel/análise , Paclitaxel/química , Análise de Componente Principal
3.
Arch Microbiol ; 202(8): 2245-2253, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32533207

RESUMO

Venturia inaequalis is a notorious fungal pathogen and show classical gene for gene interaction with its apple host. Neutral markers provide clues about history, evolutionary potential, genetic diversity and population structure of V. inaequalis. The genetic diversity and population structure of fungus indicates that the pathogen is highly diverse with the capacity to breach the scab resistance genes. In the present study, we collected 108 V. inaequalis isolates from three apple cultivars differing in Rvi1 resistance gene. Based on the AMOVA, the variation was mostly distributed among the isolates, providing evidence of non-existence of subpopulation in orchards thus founder population is difficult to arise in Kashmir apple orchards. Pair wise genetic differentiation is less due to regular occurrence of gene flow between the populations residing on different orchard as infected material is transported without stringent quarantine measures. Based on principal coordinate analysis and clustering algorithm as implemented in STRUCTURE, we observed admixture between the two subpopulations, which is quite low, suggesting the existence of pre-zygotic and post-zygotic barriers to gene flow and we cannot rule out the existence of other structures shared by accessions belonging to different varieties. Due to the continuous increase in introduction and monoculture of apple varieties, mixed orchard with different host resistance specificities are more suitable for managing the apple scab in Kashmir valley.


Assuntos
Ascomicetos/fisiologia , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita/fisiologia , Malus/microbiologia , Ascomicetos/genética , Evolução Biológica , Análise por Conglomerados , Interações Hospedeiro-Parasita/genética , Índia , Malus/genética , Doenças das Plantas/microbiologia
4.
Can J Microbiol ; 66(10): 593-599, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32485113

RESUMO

Pseudogymnoascus destructans, the fungal pathogen that causes white-nose syndrome, has killed millions of bats across eastern North America and continues to threaten new bat populations. The spread and persistence of P. destructans has likely been worsened by the ability of this fungus to grow as a saprotroph in the hibernaculum environment. Reducing the environmental growth of P. destructans may improve bat survival. Volatile organic compounds (VOCs) are attractive candidates to target environmental P. destructans, as they can permeate through textured environments that may be difficult to thoroughly contact with other control mechanisms. We tested in hibernaculum sediment the performance of VOCs that were previously shown to inhibit P. destructans growth in agar cultures and examined the inhibition kinetics and specificity of these compounds. Three VOCs, 2-methyl-1-butanol, 2-methyl-1-propanol, and 1-pentanol, were fungicidal towards P. destructans in hibernaculum sediment, fast-acting, and had greater effects against P. destructans than other Pseudogymnoascus species. Our results suggest that use of these VOCs may be considered further as an effective management strategy to reduce the environmental exposure of bats to P. destructans in hibernacula.


Assuntos
Ascomicetos/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Sedimentos Geológicos/microbiologia , Compostos Orgânicos Voláteis/farmacologia , Animais , Ascomicetos/fisiologia , Quirópteros/microbiologia , Doenças Nasais/microbiologia , Doenças Nasais/veterinária
5.
J Mycol Med ; 30(2): 100967, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32321676

RESUMO

A 44-year-old woman, victim of a road accident in Mali was diagnosed with left knee arthritis. Joint effusion aspiration and subcutaneous surgical biopsies were positive for a melanized asexual ascomycete. Using microscopy and molecular biology, the fungus was identified as Curvularia sp. In vitro antifungal susceptibility was determined by the EUCAST broth microdilution reference technique and by E-test. The patient was treated with liposomal amphotericin B before posaconazole relay. Mycological samples obtained 10 days after starting the antifungal therapy by liposomal amphotericin B were negative in culture. Curvularia spp. are environmental fungi which can under certain conditions be pathogenic for humans.


Assuntos
Acidentes de Trânsito , Artrite Infecciosa/microbiologia , Ascomicetos , Traumatismos do Joelho/complicações , Traumatismos do Joelho/microbiologia , Adulto , Antifúngicos/uso terapêutico , Artrite Infecciosa/diagnóstico , Artrite Infecciosa/tratamento farmacológico , Artrite Infecciosa/imunologia , Ascomicetos/isolamento & purificação , Ascomicetos/fisiologia , Evolução Fatal , Feminino , França , Humanos , Imunocompetência , Traumatismos do Joelho/tratamento farmacológico , Traumatismos do Joelho/imunologia , Articulação do Joelho/microbiologia , Mali , Micoses/complicações , Micoses/diagnóstico , Micoses/tratamento farmacológico , Micoses/microbiologia , Quadriplegia/etiologia , Quadriplegia/microbiologia , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/microbiologia , Doença Relacionada a Viagens
6.
Arch Virol ; 165(7): 1667-1670, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32328855

RESUMO

In this study, we report the molecular characterization of a novel positive-sense single-stranded RNA (+ssRNA) mycovirus from Botryosphaeria dothidea strain G91, which we name "Botryosphaeria dothidea botourmiavirus 1" (BdBOV-1). The complete genome of BdBOV-1 is 2547 nucleotides (nt) long, contains one open reading frame (ORF) potentially encoding an RNA-dependent RNA polymerase (RdRp), and shows a close relationship to mycoviruses of the family Botourmiaviridae. Phylogenetic analysis based on the RdRp sequences confirmed that BdBOV-1 clustered together with the members of the family Botourmiaviridae. To the best of our knowledge, this is the first report of a +ssRNA mycovirus infecting B. dothidea.


Assuntos
Ascomicetos/virologia , Micovírus/genética , Micovírus/isolamento & purificação , Vírus de RNA/isolamento & purificação , Ascomicetos/fisiologia , Micovírus/classificação , Genoma Viral , Fases de Leitura Aberta , Filogenia , Doenças das Plantas/microbiologia , RNA Replicase/genética , RNA Replicase/metabolismo , Vírus de RNA/classificação , Vírus de RNA/genética , Proteínas Virais/genética , Proteínas Virais/metabolismo
7.
BMC Plant Biol ; 20(1): 49, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32000681

RESUMO

BACKGROUND: Biotrophic fungi make intimate contact with host cells to access nutrients. Sugar is considered as the main carbon sources absorbed from host cells by pathogens. Partition, exchanges and competition for sugar at plant-pathogen interfaces are controlled by sugar transporters. Previous studies have indicated that the leaf rust resistance (Lr) gene Lr67, a natural mutation of TaSTP13 encoding a wheat sugar transport protein, confers partial resistance to all three wheat rust species and powdery mildew possibly due to weakened sugar transport activity of TaSTP13 by heterodimerization. However, one major problem that remains unresolved concerns whether TaSTP13 participates in wheat susceptibility to rust and mildew. RESULTS: In this study, expression of TaSTP13 was highly induced in wheat leaves challenged by Puccinia striiformis f. sp. tritici (Pst) and certain abiotic treatments. TaSTP13 was localized in the plasma membrane and functioned as homooligomers. In addition, a functional domain for its transport activity was identified in yeast. Suppression of TaSTP13 reduced wheat susceptibility to Pst by barley stripe mosaic virus-induced gene silencing (VIGS). While overexpression of TaSTP13 promoted Arabidopsis susceptibility to powdery mildew and led to increased glucose accumulation in the leaves. CONCLUSIONS: These results indicate that TaSTP13 is transcriptionally induced and contributes to wheat susceptibility to stripe rust, possibly by promoting cytoplasmic hexose accumulation for fungal sugar acquisition in wheat-Pst interactions.


Assuntos
Basidiomycota/fisiologia , Regulação da Expressão Gênica de Plantas , Hexoses/metabolismo , Doenças das Plantas/microbiologia , Triticum/genética , Arabidopsis/genética , Arabidopsis/microbiologia , Ascomicetos/fisiologia , Basidiomycota/genética , Citoplasma/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/microbiologia , Triticum/microbiologia
8.
BMC Plant Biol ; 20(1): 67, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32041528

RESUMO

BACKGROUND: Exserohilum turcicum is an important pathogen of both sorghum and maize, causing sorghum leaf blight and northern corn leaf blight. Because the same pathogen can infect and cause major losses for two of the most important grain crops, it is an ideal pathosystem to study plant-pathogen evolution and investigate shared resistance mechanisms between the two plant species. To identify sorghum genes involved in the E. turcicum response, we conducted a genome-wide association study (GWAS). RESULTS: Using the sorghum conversion panel evaluated across three environments, we identified a total of 216 significant markers. Based on physical linkage with the significant markers, we detected a total of 113 unique candidate genes, some with known roles in plant defense. Also, we compared maize genes known to play a role in resistance to E. turcicum with the association mapping results and found evidence of genes conferring resistance in both crops, providing evidence of shared resistance between maize and sorghum. CONCLUSIONS: Using a genetics approach, we identified shared genetic regions conferring resistance to E. turcicum in both maize and sorghum. We identified several promising candidate genes for resistance to leaf blight in sorghum, including genes related to R-gene mediated resistance. We present significant advancements in the understanding of host resistance to E. turcicum, which is crucial to reduce losses due to this important pathogen.


Assuntos
Ascomicetos/fisiologia , Genes de Plantas , Ligação Genética , Doenças das Plantas/genética , Sorghum/genética , Zea mays/genética , Meio Ambiente , Estudo de Associação Genômica Ampla , Doenças das Plantas/microbiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-32005384

RESUMO

Plant defensins have been implicated in the plant defense system, but their role in poplar immunity is still unclear. In the present study, we present evidence that PtDefensin, a putative plant defensin, participates in the defense of poplar plants against Septotis populiperda infection. After the construction of recombinant plasmid PET-32a-PtDefensin, PtDefensin protein was expressed in Escherichia coli strain BL21 (DE3) and purified through Ni-IDA resin affinity chromatography. The Trx-PtDefensin fusion protein displayed no cytotoxic activity against RAW264.7 cells but had cytotoxic activity against E. coli K12D31 cells. Analyses of PtDefensin transcript abundance showed that the expression levels of PtDefensin responded to abiotic and biotic stresses. Overexpression of PtDefensin in 'Nanlin 895' poplars (Populus × euramericana cv 'Nanlin895') increased resistance to Septotis populiperda, coupled with upregulation of MYC2 (basic helix-loop-helix (bHLH) transcription factor) related to jasmonic acid (JA) signal transduction pathways and downregulation of Jasmonate-zim domain (JAZ), an inhibitor in the JA signal transduction pathway. We speculate that systemic acquired resistance (SAR) was activated in non-transgenic poplars after S. populiperda incubation, and that induced systemic resistance (ISR) was activated more obviously in transgenic poplars after S. populiperda incubation. Hence, overexpression of PtDefensin may improve the resistance of poplar plants to pathogens.


Assuntos
Ascomicetos/fisiologia , Defensinas/genética , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/genética , Proteínas de Plantas/genética , Populus/genética , Defensinas/metabolismo , Resistência à Doença , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/microbiologia , Populus/microbiologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-32005395

RESUMO

MicroRNA (miRNA)-mediated post-transcriptional regulation plays a vital role in the response of plants to pathogens. Although the microRNA397 family has been implicated in physiological processes as an important regulator, little is known about its function in the resistance of plants to pathogens. Here, Malus hupehensis miR397, which was induced by Botryosphaeria dothidea infection, was identified to directly target M. hupehensis Laccase7 (MhLAC7). The expression analysis of mature Mh-miR397 and MhLAC7 revealed their partly opposite expression patterns. The coexpression of Mh-miR397b in MhLAC7 overexpressing Nicotiana benthamiana suppressed the accumulation of exogenous MhLAC7 and endogenous NbLAC7, which led to decreased lignin content and reduced plant resistance to Botrytis cinerea. As reflected by increasing disease severity and pathogen growth, overexpression of miR397b in both the resistant M. hupehensis and susceptible M. domestica 'Gala' resulted in an increased sensitivity to B. dothidea infection, owing to reduced LAC7 expression and lignin content; however, the inhibition of miR397 had opposite effects. MicroRNA397 functions as a negative regulator in the resistance of Malus to B. dothidea by modulating the LAC7 expression and lignin biosynthesis.


Assuntos
Ascomicetos/fisiologia , Malus/genética , MicroRNAs/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , RNA de Plantas/genética , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Lignina/biossíntese , Lignina/genética , Malus/metabolismo , Malus/microbiologia , MicroRNAs/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/microbiologia , RNA de Plantas/metabolismo , Tabaco/genética , Tabaco/metabolismo , Tabaco/microbiologia
11.
Planta ; 251(3): 59, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32025888

RESUMO

MAIN CONCLUSION: miR477 acts as a negative regulator in tea plant immunity against Pseudopestalotiopsis infection by repressing the expression of its target gene PAL. MicroRNA (miRNA)-mediated post-transcriptional regulation plays a fundamental role in various plant physiological processes, including responses to pathogens. Our previous research revealed that miR477 might be involved in the tea plant-Pseudopestalotiopsis interaction (data not shown). In the present study, the accumulation of miR477 significantly decreased in tea plants during Pseudopestalotiopsis species infection. Using miRNA and degradome data sets, the targeting of phenylalanine ammonia-lyase (PAL) by miR477 was validated by 5' RLM-RACE. GUS assay showed that the expression of PAL was post-transcriptionally regulated by miR477 and silenced by mRNA cleavage. A negative correlation between the expression of miR477 and PAL was found in tea plants infected by the pathogen. The transgenic lines overexpressing Csn-miR477 exhibited increased susceptibility to Pseudopestalotiopsis species, which was associated with reduced expression of PAL during infection. The degree of severity of the leaf lesions and the results of trypan blue staining showed that the plants overexpressing Csn-miR477 exhibited more severe damage upon pathogen infection than wild-type plants. In addition, more H2O2 and O2-, higher malondialdehyde (MDA) contents and less superoxide dismutase (SOD) and peroxidase (POD) activities were detected in the transgenic plants than in the wild-type plants after inoculation with Pseudopestalotiopsis species. Taken together, our results implied that Csn-miR477 might act as a negative regulator in pathogen-infected tea plants by inhibiting the expression of its target, PAL, and that Csn-miR477 is a candidate miRNA for improving the adaptation of tea plant to disease.


Assuntos
Ascomicetos/fisiologia , Camellia sinensis/genética , Camellia sinensis/microbiologia , MicroRNAs/genética , Fenilalanina Amônia-Liase/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Arabidopsis/genética , Sequência de Bases , Suscetibilidade a Doenças , Regulação da Expressão Gênica de Plantas , Genes de Plantas , MicroRNAs/metabolismo , Fenilalanina Amônia-Liase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reprodutibilidade dos Testes , Estresse Fisiológico/genética , Tabaco/genética , Transformação Genética
12.
PLoS One ; 15(2): e0228067, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32023268

RESUMO

During our studies on asexual fungi colonizing herbaceous litter in northern Thailand, we discovered two new fungal species, viz. Dendryphion hydei and Torula hydei spp. nov. The latter are examined, and their morphological characters are described as well as their DNA sequences from ribosomal and protein coding genes are analysed to infer their phylogenetic relationships with extant fungi. Torula hydei is different from other similar Torula species in having tiny and catenate conidia. Dendryphion hydei can be distinguished from other similar Dendryphion species in having large conidiophores and subhyaline to pale olivaceous brown, 2-4(-5)-septate conidia. Multigene phylogenetic analyses of a combined LSU, SSU, TEF1-α, RPB2 and ITS DNA sequence dataset generated from maximum likelihood and Bayesian inference analyses indicate that T. hydei forms a distinct lineage and basal to T. fici. Dendryphion hydei forms a distinct lineage and basal to D. europaeum, D. comosum, D. aquaticum and D. fluminicola within Torulaceae (Pleosporales, Dothideomycetes).


Assuntos
Ascomicetos/genética , Cryptococcus/genética , Ascomicetos/classificação , Ascomicetos/fisiologia , Teorema de Bayes , Cryptococcus/classificação , Cryptococcus/fisiologia , DNA Fúngico/química , DNA Fúngico/metabolismo , Filogenia , Análise de Sequência de DNA , Tailândia
13.
Arch Virol ; 165(4): 1027-1031, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32056004

RESUMO

Hypoviruses are positive-sense single-stranded RNA mycovirus that infect filamentous fungi. However, hypoviruses have not been reported in Bipolaris oryzae, an important phytopathogenic fungus in water bamboo and rice. Here, we report the characterization of a novel hypovirus, tentatively named "Bipolaris oryzae hypovirus 1" (BoHV1), isolated from strain ES35 of B. oryzae infecting water bamboo. The complete genome of BoHV1 consists of 13,596 nucleotides and a poly(A) tail at the 3' end. BoHV1 has single open reading frame (ORF) and encodes a putative polyprotein (4,218 amino acids) containing four potential conserved domains for a papain-like protease, a protein of unknown function (DUF3525), RNA-dependent RNA polymerase (RdRp), and helicase. Phylogenetic analysis of the polyprotein, RdRp, and helicase domains suggested that BoHV1 belongs to the genus Hypovirus within the family Hypoviridae. This is the first report of the presence of a hypovirus in the phytopathogenic fungus B. oryzae.


Assuntos
Ascomicetos/virologia , Micovírus/isolamento & purificação , Genoma Viral , Vírus de RNA/isolamento & purificação , Ascomicetos/fisiologia , Sequência de Bases , Micovírus/classificação , Micovírus/genética , Fases de Leitura Aberta , Filogenia , Doenças das Plantas/microbiologia , Vírus de RNA/classificação , Vírus de RNA/genética , Sasa/microbiologia , Proteínas Virais/genética , Sequenciamento Completo do Genoma
14.
J Mycol Med ; 30(1): 100918, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31926829

RESUMO

We report a case of cerebral phaeohyphomycosis, a fungal brain infection due to a dark (dematiaceous) fungi in a 6-year-old French Guyanese boy. The child presented fever and drowsiness due to several paraventricular brain abscesses. Neurological surgeries were performed to reduce intracranial hypertension and to obtain abscess biopsies. Mycological cultures of intraoperative samples led to the diagnosis of cerebral phaeohyphomycosis due to Cladophialophora bantiana. The patient neurological status deteriorated and remained critical after several weeks of combination antifungal therapy with voriconazole 8mg/kg/day, liposomal amphotericin B 10mg/kg/day and flucytosine 200mg/kg/day. A complete surgical resection was not possible because of multiple small abscesses. A multidisciplinary ethical staff decided on home medical care with palliative ventriculoperitoneal shunt, nasogastric feeding and analgesics. One year later, the patient's neurological condition had improved and cerebral lesions had regressed, while he had not received any antifungal treatment but only traditional medicines. Cerebral phaeohyphomycosis are rare diseases affecting immunocompromised but also apparently non-immunocompromised patients, as in this case. A complete surgical resection is not always possible and mortality rates are high in spite of treatments with a combination of antifungals. The diagnosis may be difficult because of these dematiaceous fungi's slowly growing and their potential pathogenicity for laboratory staff.


Assuntos
Ascomicetos/isolamento & purificação , Infecções Fúngicas do Sistema Nervoso Central/diagnóstico , Feoifomicose Cerebral/diagnóstico , Antifúngicos/uso terapêutico , Ascomicetos/fisiologia , Abscesso Encefálico/diagnóstico , Abscesso Encefálico/microbiologia , Abscesso Encefálico/terapia , Infecções Fúngicas do Sistema Nervoso Central/microbiologia , Infecções Fúngicas do Sistema Nervoso Central/terapia , Feoifomicose Cerebral/microbiologia , Feoifomicose Cerebral/terapia , Criança , Terapia Combinada , Nutrição Enteral , Guiana Francesa , Humanos , Imunocompetência , Intubação Gastrointestinal , Masculino , Procedimentos Neurocirúrgicos , Derivação Ventriculoperitoneal
15.
Int J Mol Sci ; 21(1)2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31947730

RESUMO

Powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt) is one of many severe diseases that threaten bread wheat (Triticum aestivum L.) yield and quality worldwide. The discovery and deployment of powdery mildew resistance genes (Pm) can prevent this disease epidemic in wheat. In a previous study, we transferred the powdery mildew resistance gene Pm57 from Aegilops searsii into common wheat and cytogenetically mapped the gene in a chromosome region with the fraction length (FL) 0.75-0.87, which represents 12% segment of the long arm of chromosome 2Ss#1. In this study, we performed RNA-seq using RNA extracted from leaf samples of three infected and mock-infected wheat-Ae. searsii 2Ss#1 introgression lines at 0, 12, 24, and 48 h after inoculation with Bgt isolates. Then we designed 79 molecular markers based on transcriptome sequences and physically mapped them to Ae. searsii chromosome 2Ss#1- in seven intervals. We used these markers to identify 46 wheat-Ae. searsii 2Ss#1 recombinants induced by ph1b, a deletion mutant of pairing homologous (Ph) genes. After analyzing the 46 ph1b-induced 2Ss#1L recombinants in the region where Pm57 is located with different Bgt-responses, we physically mapped Pm57 gene on the long arm of 2Ss#1 in a 5.13 Mb genomic region, which was flanked by markers X67593 (773.72 Mb) and X62492 (778.85 Mb). By comparative synteny analysis of the corresponding region on chromosome 2B in Chinese Spring (T. aestivum L.) with other model species, we identified ten genes that are putative plant defense-related (R) genes which includes six coiled-coil nucleotide-binding site-leucine-rich repeat (CNL), three nucleotide-binding site-leucine-rich repeat (NL) and a leucine-rich receptor-like repeat (RLP) encoding proteins. This study will lay a foundation for cloning of Pm57, and benefit the understanding of interactions between resistance genes of wheat and powdery mildew pathogens.


Assuntos
Aegilops/genética , Ascomicetos/fisiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Aegilops/microbiologia , Cromossomos de Plantas , Resistência à Doença , Genes de Plantas , Mapeamento Físico do Cromossomo , Triticum/genética , Triticum/microbiologia
16.
FEMS Microbiol Ecol ; 96(2)2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31960913

RESUMO

Since its introduction into the USA, Pseudogymnoascus destructans (Pd), the fungal pathogen of white-nose syndrome, has killed millions of bats. Recently, bacteria capable of inhibiting the growth of Pd have been identified within bat microbial assemblages, leading to increased interest in elucidating bacterial assemblage-pathogen interactions. Our objectives were to determine if bat cutaneous bacteria have antifungal activity against Pd, and correlate differences in the bat cutaneous microbiota with the presence/absence of Pd. We hypothesized that the cutaneous microbiota of bats is enriched with antifungal bacteria, and that the skin assemblage will correlate with Pd status. To test this, we sampled bat microbiota, adjacent roost surfaces and soil from Pd positive caves to infer possible overlap of antifungal taxa, we tested these bacteria for bioactivity in vitro, and lastly compared bacterial assemblages using both amplicon and shotgun high-throughput DNA sequencing. Results suggest that the presence of Pd has an inconsistent influence on the bat cutaneous microbial assemblage across sites. Operational taxonomic units (OTUs) that corresponded with cultured antifungal bacteria were present within all sample types but were significantly more abundant on bat skin relative to the environment. Additionally, the microbial assemblage of Pd negative bats was found to have more OTUs that corresponded to antifungal taxa than positive bats, suggesting an interaction between the fungal pathogen and cutaneous microbial assemblage.


Assuntos
Ascomicetos/fisiologia , Fenômenos Fisiológicos Bacterianos , Quirópteros/microbiologia , Microbiota/fisiologia , Animais , Antifúngicos , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/isolamento & purificação , Bactérias/isolamento & purificação , Cavernas , Sequenciamento de Nucleotídeos em Larga Escala , Pele/microbiologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-31928657

RESUMO

Sclerotinia sclerotiorum causes a devastating disease in oilseed rape (Brassica napus), resulting in major economic losses. Resistance response of B. napus against S. sclerotiorum exhibits a typical quantitative disease resistance (QDR) characteristic, but the molecular determinants of this QDR are largely unknown. In this study, we isolated a B. napus mitogen-activated protein kinase gene, BnaMPK6, and found that BnaMPK6 expression is highly responsive to infection by S. sclerotiorum and treatment with salicylic acid (SA) or jasmonic acid (JA). Moreover, overexpression (OE) of BnaMPK6 significantly enhances resistance to S. sclerotiorum, whereas RNAi in BnaMPK6 significantly reduces this resistance. These results showed that BnaMPK6 plays an important role in defense to S. sclerotiorum. Furthermore, expression of defense genes associated with SA-, JA- and ethylene (ET)-mediated signaling was investigated in BnaMPK6-RNAi, WT and BnaMPK6-OE plants after S. sclerotiorum infection, and consequently, it was indicated that the activation of ET signaling by BnaMPK6 may play a role in the defense. Further, four BnaMPK6-encoding homologous loci were mapped in the B. napus genome. Using the allele analysis and expression analysis on the four loci, we demonstrated that the locus BnaA03.MPK6 makes an important contribution to QDR against S. sclerotiorum. Our data indicated that BnaMPK6 is a previously unknown determinant of QDR against S. sclerotiorum in B. napus.


Assuntos
Ascomicetos/fisiologia , Brassica napus/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Brassica napus/microbiologia , Resistência à Doença/genética , Proteínas Quinases Ativadas por Mitógeno/química , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Alinhamento de Sequência
19.
Artigo em Inglês | MEDLINE | ID: mdl-31928678

RESUMO

Ethylene response factor (ERF) is a plant-specific transcription factor involved in many biological processes including root formation, hypocotyl elongation, fruit ripening, organ senescence and stress responses, as well as fruit quality formation. However, its underlying mechanism in plant pathogen defense against Botryosphaeria dothidea (B. dothidea) remains poorly understood. Here, we isolate MdERF11, an apple nucleus-localized ERF transcription factor, from apple cultivar 'Royal Gala'. qRT-PCR assays show that the expression of MdERF11 is significantly induced in apple fruits after B. dothidea infection. Overexpression of MdERF11 gene in apple calli significantly increases the resistance to B.dothidea infection, while silencing MdERF11 in apple calli results in reduced resistance. Ectopic expression of MdERF11 in Arabidopsis also exhibits enhanced resistance to B. dothidea infection compared to that of wild type. Infections in apple calli and Arabidopsis leaves by B. dothidea respectively cause an increase in endogenous levels of salicylic acid (SA) followed by induction of SA synthesis-related and signaling-related gene expression. Taken together, these findings illustrate a potential mechanism by which MdERF11 elevates plant pathogen defense against B. dothidea by regulating SA synthesis pathway.


Assuntos
Ascomicetos/fisiologia , Malus/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Resistência à Doença/genética , Malus/metabolismo , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo
20.
Phytopathology ; 110(2): 494-504, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31464158

RESUMO

Cochliobolus heterostrophus is the causal agent of southern corn leaf blight, a destructive disease on maize worldwide. However, how it regulates virulence on maize is still largely unknown. Here, we report that two copper transporter genes, ChCTR1 and ChCTR4, are required for its virulence. chctr1 and chctr4 mutants showed attenuated virulence on maize compared with the wild-type strain TM17 but development phenotypes of those mutants on media with or without infection-related stress agents were the same as the wild-type strain. Moreover, ChCTR1 and ChCTR4 play critical roles in appressorium formation and mutation of ChCTR1 or ChCTR4 suppresses the appressorium formation. Furthermore, copper-chelating agent ammonium tetrathiomolybdate suppressed the appressorium formation and virulence of C. heterostrophus on maize, whereas copper ions enhanced the appressorium formation and virulence on maize. The results indicate that copper ions are required for appressorium formation and virulence of C. heterostrophus on maize and are acquired from the environment by two copper transporters: ChCTR1 and ChCTR4.


Assuntos
Ascomicetos , Virulência , Zea mays , Ascomicetos/patogenicidade , Ascomicetos/fisiologia , Cobre/química , Íons/química , Doenças das Plantas/microbiologia , Zea mays/microbiologia
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