Microbiologia
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11840
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Resultados da Pesquisa
Item 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.Item Development of molecular markers based on retrotransposons for the analysis of genetic variability in Moniliophthora perniciosa(European Journal of Plant Pathology, 2012-11) Santana, Mateus Ferreira; Araújo, Elza Fernandes de; Queiroz, Marisa Vieira de; Souza, Jorge Teodoro de; Mizubuti, Eduardo Seiti GomideMoniliophthora perniciosa is a fungus that causes witches’ broom disease (WBD) in the cacao tree (Theobroma cacao). The M. perniciosa genome contains different transposable elements; this prompted an evaluation of the use of its retrotransposons as molecular markers for population studies. The inter-retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymorphism (REMAP) techniques were used to study the variability of 70 M. perniciosa isolates from different geographic origins and biotypes. A total of 43 loci was amplified. Cluster analysis of different geographical regions of C biotype revealed two large groups in the state of Bahia, Brazil. Techniques using retrotransposon-based molecular markers showed advantages over previously used molecular techniques for the study of genetic variability in M. perniciosa.Item MpSaci is a widespread gypsy-Ty3 retrotransposon highly represented by non-autonomous copies in the Moniliophthora perniciosa genome(Current Genetics, 2015-05) Araújo, Elza F.; Queiroz, Casley B.; Queiroz, Marisa V.; Pereira, Jorge F.; Brommonschenkel, Sérgio H.; Costa, Gustavo G. L.; Carazzolle, Marcelo F.; Pereira, Gonçalo A. G.Transposons are an important source of genetic variation. The phytopathogen Moniliophthora perniciosa shows high level of variability but little is known about the role of class I elements in shaping its genome. In this work, we aimed the characterization of a new gypsy/Ty3 retrotransposon species, named MpSaci, in the M. perniciosa genome. These elements are largely variable in size, ranging from 4 to 15 kb, and harbor direct long terminal repeats (LTRs) with varying degrees of similarity. Approximately, all of the copies are non-autonomous as shifts in the reading frame and stop codons were detected. Only two elements (MpSaci6 and MpSaci9) code for GAG and POL proteins that possess functional domains. Conserved domains that are typically not found in retrotransposons were detected and could potentially impact the expression of neighbor genes. Solo LTRs and several LARDs (large retrotransposon derivative) were detected. Unusual elements containing small sequences with or without interruptions that are similar to gag or different pol domains and presenting LTRs with different levels of similarities were identified. Methylation was observed in MpSaci reverse transcriptase sequences. Distribution analysis indicates that MpSaci elements are present in high copy number in the genomes of C-, S- and L-biotypes of M. perniciosa. In addition, C-biotype isolates originating from the state of Bahia have fragments in common with isolates from the Amazon region and two hybridization profiles related to two chromosomal groups. RT-PCR analysis reveals that the gag gene is constitutively expressed and that the expression is increased at least three-fold with nutrient depravation even though no new insertion were observed. These findings point out that MpSaci collaborated and, even though is primarily represented by non-autonomous elements, still might contribute to the generation of genetic variability in the most important cacao pathogen in Brazil.Item High genetic variability in endophytic fungi from the genus Diaporthe isolated from common bean (Phaseolus vulgaris L.) in Brazil(Journal of Applied Microbiology, 2015-11-06) Santos, T.T. dos; Souza Leite, T. de; Queiroz, C.B. de; Araújo, E.F. de; Pereira, O.L.; Queiroz, M.V. deThe goals of the present study were to identify, to analyse the phylogenetic relations and to evaluate the genetic variability in Diaporthe endophytic isolates from common bean. Diaporthe sp., D. infecunda and D. phaseolorum strains were identified using multilocus phylogeny (rDNA ITS region; EF1‐α, β‐tubulin, and calmodulin genes). IRAP (Inter‐Retrotransposon Amplified Polymorphism) and REMAP (Retrotransposon‐Microsatellite Amplified Polymorphism) molecular markers reveal the existence of high genetic variability, especially among D. infecunda isolates. It was concluded that the multilocus phylogenetic approach was more effective than individual analysis of ITS sequences, in identifying the isolates to species level, and that IRAP and REMAP markers can be used for studying the genetic variability in the genus Diaporthe particularly at the intraspecific level. The combined use of molecular tools such as multilocus phylogenetic approach and molecular markers, as performed in this study, is the best way to distinguish endophytic strains of Diaporthe isolated from common bean (Phaseolus vulgaris L.).Item Use of the IRAP marker to study genetic variability in Pseudocercospora fijiensis populations(Current Microbiology, 2013-11-05) Queiroz, Casley Borges de; Santana, Mateus Ferreira; Silva, Gilvan Ferreira da; Mizubuti, Eduardo Seiti Gomide; Araújo, Elza Fernandes de; Queiroz, Marisa Vieira dePseudocercospora fijiensis is the etiological agent of black Sigatoka, which is currently considered as one of the most destructive banana diseases in all locations where it occurs. It is estimated that a large portion of the P. fijiensis genome consists of transposable elements, which allows researchers to use transposon-based molecular markers in the analysis of genetic variability in populations of this pathogen. In this context, the inter-retrotransposon-amplified polymorphism (IRAP) was used to study the genetic variability in P. fijiensis populations from different hosts and different geographical origins in Brazil. A total of 22 loci were amplified and 77.3 % showed a polymorphism. Cluster analysis revealed two major groups in Brazil. The observed genetic diversity (H E) was 0.22, and through molecular analysis of variance, it was determined that the greatest genetic variability occurs within populations. The discriminant analysis of principal components revealed no structuring related to the geographical origin of culture of the host. The IRAP-based marker system is a suitable tool for the study of genetic variability in P. fijiensis.