Microbiologia

URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11840

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Resultados da Pesquisa

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    Polymorphism in the internal transcribed spacer (ITS) of the ribosomal DNA of 26 isolates of ectomycorrhizal fungi
    (Genetics and Molecular Biology, 2002) Gomes, Eliane A.; Kasuya, Maria Catarina M.; Barros, Everaldo G. de; Borges, Arnaldo C.; Araújo, Elza F.
    Inter- and intraspecific variation among 26 isolates of ectomycorrhizal fungi belonging to 8 genera and 19 species were evaluated by analysis of the internal transcribed sequence (ITS) of the rDNA region using restriction fragment length polymorphism (RFLP). The ITS region was first amplified by polymerase chain reaction (PCR) with specific primers and then cleaved with different restriction enzymes. Amplification products, which ranged between 560 and 750 base pairs (bp), were obtained for all the isolates analyzed. The degree of polymorphism observed did not allow proper identification of most of the isolates. Cleavage of amplified fragments with the restriction enzymes Alu I, Hae III, Hinf I, and Hpa II revealed extensive polymorphism. All eight genera and most species presented specific restriction patterns. Species not identifiable by a specific pattern belonged to two genera: Rhizopogon (R. nigrescens, R. reaii, R. roseolus, R. rubescens and Rhizopogon sp.), and Laccaria (L. bicolor and L. amethystea). Our data confirm the potential of ITS region PCR-RFLP for the molecular characterization of ectomycorrhizal fungi and their identification and monitoring in artificial inoculation programs.
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    The glyceraldehyde-3-phosphate dehydrogenase gene of Moniliophthora perniciosa, the causal agent of witches' broom disease of Theobroma cacao
    (Genetics and Molecular Biology, 2009) Lima, Juliana O.; Pereira, Jorge F.; Rincones, Johana; Barau, Joan G.; Araújo, Elza F.; Pereira, Gonçalo A. G.; Queiroz, Marisa V.
    This report describes the cloning, sequence and expression analysis of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene of Moniliophthora perniciosa, the most important pathogen of cocoa in Brazil. Southern blot analysis revealed the presence of a single copy of the GAPDH gene in the M. perniciosa genome (MpGAPDH). The complete MpGAPDH coding sequence contained 1,461 bp with eight introns that were conserved in the GAPDH genes of other basidiomycete species. The cis-elements in the promoter region of the MpGAPDH gene were similar to those of other basidiomycetes. Likewise, the MpGAPDH gene encoded a putative 339 amino acid protein that shared significant sequence similarity with other GAPDH proteins in fungi, plants, and metazoans. Phylogenetic analyses clustered the MPGAPDH protein with other homobasidiomycete fungi of the family Tricholomataceae. Expression analysis of the MpGAPDH gene by real-time PCR showed that this gene was more expressed (~1.3X) in the saprotrophic stage of this hemibiotrophic plant pathogen than in the biotrophic stage when grown in cacao extracts.
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    PCR amplification and sequence analyses of Reverse Transcriptase-like genes in Crinipellis perniciosa isolates
    (Fitopatologia Brasileira, 2007-09) Pereira, Jorge F.; Ignacchiti, Mariana D. C.; Araújo, Elza F.; Brommonschenkel, Sérgio H.; Cascardo, Júlio C. M.; Pereira, Gonçalo A. G.; Queiroz, Marisa V.
    Reverse transcriptase (RT) sequence analysis is an important technique used to detect the presence of transposable elements in a genome. Putative RT sequences were analyzed in the genome of the pathogenic fungus C. perniciosa, the causal agent of witches' broom disease of cocoa. A 394 bp fragment was amplified from genomic DNA of different isolates of C. perniciosa belonging to C-, L-, and S-biotypes and collected from various geographical areas. The cleavage of PCR products with restriction enzymes and the sequencing of various RT fragments indicated the presence of several sequences showing transition events (G:C to A:T). Southern blot analysis revealed high copy numbers of RT signals, forming different patterns among C-, S-, and L-biotype isolates. Sequence comparisons of the predicted RT peptide indicate a close relationship with the RT protein from the gypsy family of LTR-retrotransposons. The possible role of these retrotransposons in generating genetic variability in the homothallic C. perniciosa is discussed.
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    Small heat shock proteins in the development of thermotolerance in Pisolithus sp.
    (Journal of Thermal Biology, 2005-12) Ferreira, Adão S.; Kasuya, Maria C. M.; Araújo, Elza F.; Borges, Arnaldo C.; Tótola, Marco. R.
    Small heat shock proteins (HSPs) have been shown to confer thermotolerance in many organisms. Here, we demonstrate that small HSPs (sHSPs) can also be involved in development of thermotolerance in Pisolithus sp. In heat shock response, Pisolithus isolate RV82 synthesized proteins of molecular mass 28, 26 and 15–18 kDa. These group of proteins are synthesized when mycelial mass are exposed to heat shock temperature (42 °C) for short period (30 min) and incubated back at 28 °C, the optimal temperature for growth. Our results show sHSPs are an important biochemical alteration in ectomycorrhizal fungi under thermal stress.
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    The glyceraldehyde-3-phosphate dehydrogenase gene of Moniliophthoraperniciosa, the causal agent of witches' broom disease of Theobroma cacao
    (Genetics and Molecular Biology, 2008-12-05) Lima, Juliana O.; Pereira, Jorge F.; Rincones, Johana; Barau, Joan G.; Araújo, Elza F.; Pereira, Gonçalo A.G.; Queiroz, Marisa V.
    This report describes the cloning, sequence and expression analysis of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene of Moniliophthora perniciosa, the most important pathogen of cocoa in Brazil. Southern blot analysis revealed the presence of a single copy of the GAPDH gene in the M. perniciosa genome (MpGAPDH). The complete MpGAPDH coding sequence contained 1,461 bp with eight introns that were conserved in the GAPDH genes of other basidiomycete species. The cis-elements in the promoter region of the MpGAPDH gene were similar to those of other basidiomycetes. Likewise, the MpGAPDH gene encoded a putative 339 amino acid protein that shared significant sequence similarity with other GAPDH proteins in fungi, plants, and metazoans. Phylogenetic analyses clustered the MPGAPDH protein with other homobasidiomycete fungi of the family Tricholomataceae. Expression analysis of the MpGAPDH gene by real-time PCR showed that this gene was more expressed (~1.3X) in the saprotrophic stage of this hemibiotrophic plant pathogen than in the biotrophic stage when grown in cacao extracts.