RESUMO
In Mexico, Fusarium mexicanum has been reported causing mango malformation disease and big-leaf mahogany malformation disease. Our objective was to determine the genetic diversity of F. mexicanum isolates obtained from malformed big-leaf mahogany and mango trees, using an internal simple sequence repeat (ISSR) analysis. A total of 61 isolates of F. mexicanum, 32 from mango and 29 from big-leaf mahogany, were initially genotyped using fourteen ISSR primers. Data from five primers that produced the highest number of polymorphic bands were selected for further analysis. The primers generated 49 polymorphic bands (85.96%) from a total of 57 fragments ranging in size from 250 to 2800 bp, with an average of 11.4 bands per primer. An analysis of molecular variance (AMOVA) indicated that the variation within populations, isolates grouped by host and geographic origin, was significant (43%), followed by the variation between the big-leaf mahogany versus mango isolates (34%), while among populations the variation was the lowest (22%). The genetic fingerprints suggested that genetic variability of F. mexicanum populations are structured by the host of origin rather than the geographic region.
Assuntos
Fusariose/metabolismo , Fusarium/genética , Impressões Digitais de DNA/métodos , Fusariose/genética , Fusarium/metabolismo , Variação Genética/genética , Genética Populacional/métodos , Genótipo , Mangifera/microbiologia , Meliaceae/microbiologia , México , Repetições de Microssatélites/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Análise de Sequência de DNA/métodos , Árvores/genéticaRESUMO
Fusarium verticillioides is a pathogen of agriculturally important crops, especially maize. It is considered one of the most important pathogens responsible for fumonisin contamination of food products, which causes severe, chronic, and acute intoxication in humans and animals. Moreover, it is recognized as a cause of localized infections in immunocompetent patients and disseminated infections among severely immunosuppressed patients. Several molecular tools have been used to analyze the intraspecific variability of fungi. The objective of this study was to use molecular markers to compare pathogenic isolates of F. verticillioides and isolates of the same species obtained from clinical samples of patients with Fusarium mycoses. The molecular markers that we used were inter-simple sequence repeat markers (primers GTG5 and GACA4), intron splice site primer (primer EI1), random amplified polymorphic DNA marker (primer OPW-6), and restriction fragment length polymorphism-internal transcribed spacer (ITS) from rDNA. From the data obtained, clusters were generated based on the UPGMA clustering method. The amplification products obtained using primers ITS4 and ITS5 and loci ITS1-5.8-ITS2 of the rDNA yielded fragments of approximately 600 bp for all the isolates. Digestion of the ITS region fragment using restriction enzymes such as EcoRI, DraI, BshI, AluI, HaeIII, HinfI, MspI, and PstI did not permit differentiation among pathogenic and clinical isolates. The inter-simple sequence repeat, intron splice site primer, and random amplified polymorphic DNA markers presented high genetic homogeneity among clinical isolates in contrast to the high variability found among the phytopathogenic isolates of F. verticillioides.
Assuntos
DNA Ribossômico/genética , Fusarium/genética , Repetições de Microssatélites/genética , Zea mays/microbiologia , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , Fusariose/genética , Fusariose/microbiologia , Fusarium/patogenicidade , Marcadores Genéticos , Variação Genética , HumanosRESUMO
The Cape gooseberry (Physalisperuviana L) is an Andean exotic fruit with high nutritional value and appealing medicinal properties. However, its cultivation faces important phytosanitary problems mainly due to pathogens like Fusarium oxysporum, Cercosporaphysalidis and Alternaria spp. Here we used the Cape gooseberry foliar transcriptome to search for proteins that encode conserved domains related to plant immunity including: NBS (Nucleotide Binding Site), CC (Coiled-Coil), TIR (Toll/Interleukin-1 Receptor). We identified 74 immunity related gene candidates in P. peruviana which have the typical resistance gene (R-gene) architecture, 17 Receptor like kinase (RLKs) candidates related to PAMP-Triggered Immunity (PTI), eight (TIR-NBS-LRR, or TNL) and nine (CC-NBS-LRR, or CNL) candidates related to Effector-Triggered Immunity (ETI) genes among others. These candidate genes were categorized by molecular function (98%), biological process (85%) and cellular component (79%) using gene ontology. Some of the most interesting predicted roles were those associated with binding and transferase activity. We designed 94 primers pairs from the 74 immunity-related genes (IRGs) to amplify the corresponding genomic regions on six genotypes that included resistant and susceptible materials. From these, we selected 17 single band amplicons and sequenced them in 14 F. oxysporum resistant and susceptible genotypes. Sequence polymorphisms were analyzed through preliminary candidate gene association, which allowed the detection of one SNP at the PpIRG-63 marker revealing a nonsynonymous mutation in the predicted LRR domain suggesting functional roles for resistance.
Assuntos
Fusariose/genética , Fusariose/imunologia , Fusarium/imunologia , Physalis/genética , Physalis/imunologia , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Sequência de Aminoácidos , Sequência de Bases , Bases de Dados Genéticas , Resistência à Doença/genética , Resistência à Doença/imunologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Anotação de Sequência Molecular , Fenótipo , Physalis/microbiologia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Polimorfismo de Nucleotídeo Único , TranscriptomaRESUMO
BACKGROUND: The species of T. harzianum are well known for their biocontrol activity against many plant pathogens. However, there is a lack of studies concerning its use as a biological control agent against F. solani, a pathogen involved in several crop diseases. In this study, we have used subtractive library hybridization (SSH) and quantitative real-time PCR (RT-qPCR) techniques in order to explore changes in T. harzianum genes expression during growth on cell wall of F. solani (FSCW) or glucose. RT-qPCR was also used to examine the regulation of 18 genes, potentially involved in biocontrol, during confrontation between T. harzianum and F. solani. RESULTS: Data obtained from two subtractive libraries were compared after annotation using the Blast2GO suite. A total of 417 and 78 readable EST sequence were annotated in the FSCW and glucose libraries, respectively. Functional annotation of these genes identified diverse biological processes and molecular functions required during T. harzianum growth on FSCW or glucose. We identified various genes of biotechnological value encoding to proteins which function such as transporters, hydrolytic activity, adherence, appressorium development and pathogenesis. Fifteen genes were up-regulated and sixteen were down-regulated at least at one-time point during growth of T. harzianum in FSCW. During the confrontation assay most of the genes were up-regulated, mainly after contact, when the interaction has been established. CONCLUSIONS: This study demonstrates that T. harzianum expressed different genes when grown on FSCW compared to glucose. It provides insights into the mechanisms of gene expression involved in mycoparasitism of T. harzianum against F. solani. The identification and evaluation of these genes may contribute to the development of an efficient biological control agent.
Assuntos
Parede Celular/genética , Fusarium/patogenicidade , Controle Biológico de Vetores , Trichoderma/crescimento & desenvolvimento , Trichoderma/genética , Biotecnologia , Etiquetas de Sequências Expressas , Fusariose/genética , Fusariose/patologia , Fusarium/genética , Regulação Fúngica da Expressão Gênica , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Trichoderma/patogenicidadeRESUMO
ß-1,3-Glucan binding proteins (ßGBPs) are soluble pattern recognition proteins/receptors that bind to ß-1,3-glucans from fungi cell walls. In crustaceans, ßGBPs are abundant plasmatic proteins produced by the hepatopancreas, and have been proved to play multiple biological functions. Here, we purified and characterized novel members of the ßGBP family from the hemolymph of two Brazilian shrimps, Farfantepenaeus paulensis (FpßGBP) and Litopenaeus schmitti (LsßGBP). As observed for other crustacean species, FpßGBP and LsßGBP are monomeric proteins (â¼100kDa) able to enhance the activation of the prophenoloxidase system, a potent antimicrobial defense conserved in arthropods. More interestingly, we provided here evidence for a novel biological activity for shrimp ßGBPs: the agglutination of fungal cells. Finally, we investigated the modulation of the ßGBP gene in F. paulensis shrimps experimentally infected with a cognate fungal pathogen, Fusarium solani. From our expression data, ßGBP gene is constitutively expressed in hepatopancreas and not modulated upon a non-lethal fungal infection. Herein, we have improved our knowledge about the ßGBP family by the characterization of a novel biological role for this multifunctional protein in shrimp.