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1.  Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses 
Pedrosa, Fábio O. | Monteiro, Rose Adele | Wassem, Roseli | Cruz, Leonardo M. | Ayub, Ricardo A. | Colauto, Nelson B. | Fernandez, Maria Aparecida | Fungaro, Maria Helena P. | Grisard, Edmundo C. | Hungria, Mariangela | Madeira, Humberto M. F. | Nodari, Rubens O. | Osaku, Clarice A. | Petzl-Erler, Maria Luiza | Terenzi, Hernán | Vieira, Luiz G. E. | Steffens, Maria Berenice R. | Weiss, Vinicius A. | Pereira, Luiz F. P. | Almeida, Marina I. M. | Alves, Lysangela R. | Marin, Anelis | Araujo, Luiza Maria | Balsanelli, Eduardo | Baura, Valter A. | Chubatsu, Leda S. | Faoro, Helisson | Favetti, Augusto | Friedermann, Geraldo | Glienke, Chirlei | Karp, Susan | Kava-Cordeiro, Vanessa | Raittz, Roberto T. | Ramos, Humberto J. O. | Ribeiro, Enilze Maria S. F. | Rigo, Liu Un | Rocha, Saul N. | Schwab, Stefan | Silva, Anilda G. | Souza, Eliel M. | Tadra-Sfeir, Michelle Z. | Torres, Rodrigo A. | Dabul, Audrei N. G. | Soares, Maria Albertina M. | Gasques, Luciano S. | Gimenes, Ciela C. T. | Valle, Juliana S. | Ciferri, Ricardo R. | Correa, Luiz C. | Murace, Norma K. | Pamphile, João A. | Patussi, Eliana Valéria | Prioli, Alberto J. | Prioli, Sonia Maria A. | Rocha, Carmem Lúcia M. S. C. | Arantes, Olívia Márcia N. | Furlaneto, Márcia Cristina | Godoy, Leandro P. | Oliveira, Carlos E. C. | Satori, Daniele | Vilas-Boas, Laurival A. | Watanabe, Maria Angélica E. | Dambros, Bibiana Paula | Guerra, Miguel P. | Mathioni, Sandra Marisa | Santos, Karine Louise | Steindel, Mario | Vernal, Javier | Barcellos, Fernando G. | Campo, Rubens J. | Chueire, Ligia Maria O. | Nicolás, Marisa Fabiana | Pereira-Ferrari, Lilian | da Conceição Silva, José L. | Gioppo, Nereida M. R. | Margarido, Vladimir P. | Menck-Soares, Maria Amélia | Pinto, Fabiana Gisele S. | Simão, Rita de Cássia G. | Takahashi, Elizabete K. | Yates, Marshall G. | Souza, Emanuel M.
PLoS Genetics  2011;7(5):e1002064.
The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.
Author Summary
In this work we describe the genome of H. seropedicae SmR1, a bacterium capable of fixing nitrogen and promoting the growth of important plant crops such as maize, rice, and sugar cane. Several investigations have shown that H. seropedicae supplies fixed nitrogen to the associated plant and increases grain productivity up to 50%. In the genome of H. seropedicae, we identified all the genes involved in the nitrogen fixation process and its regulation and, in addition, genes potentially involved in the establishment of efficient interaction with the host plant. Our analyses also revealed that this bacterium has a highly versatile metabolism capable of synthesizing and degrading a large number of organic and inorganic compounds. We believe that the knowledge of the genome of this bacterium will direct research to a better understanding of this important endophytic organism and allow the construction of new strains with enhanced agronomic efficiency.
PMCID: PMC3093359  PMID: 21589895
2.  Dual RNA-seq transcriptional analysis of wheat roots colonized by Azospirillum brasilense reveals up-regulation of nutrient acquisition and cell cycle genes 
BMC Genomics  2014;15(1):378.
The rapid growth of the world’s population demands an increase in food production that no longer can be reached by increasing amounts of nitrogenous fertilizers. Plant growth promoting bacteria (PGPB) might be an alternative to increase nitrogenous use efficiency (NUE) in important crops such wheat. Azospirillum brasilense is one of the most promising PGPB and wheat roots colonized by A. brasilense is a good model to investigate the molecular basis of plant-PGPB interaction including improvement in plant-NUE promoted by PGPB.
We performed a dual RNA-Seq transcriptional profiling of wheat roots colonized by A. brasilense strain FP2. cDNA libraries from biological replicates of colonized and non-inoculated wheat roots were sequenced and mapped to wheat and A. brasilense reference sequences. The unmapped reads were assembled de novo. Overall, we identified 23,215 wheat expressed ESTs and 702 A. brasilense expressed transcripts. Bacterial colonization caused changes in the expression of 776 wheat ESTs belonging to various functional categories, ranging from transport activity to biological regulation as well as defense mechanism, production of phytohormones and phytochemicals. In addition, genes encoding proteins related to bacterial chemotaxi, biofilm formation and nitrogen fixation were highly expressed in the sub-set of A. brasilense expressed genes.
PGPB colonization enhanced the expression of plant genes related to nutrient up-take, nitrogen assimilation, DNA replication and regulation of cell division, which is consistent with a higher proportion of colonized root cells in the S-phase. Our data support the use of PGPB as an alternative to improve nutrient acquisition in important crops such as wheat, enhancing plant productivity and sustainability.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-378) contains supplementary material, which is available to authorized users.
PMCID: PMC4042000  PMID: 24886190
RNA-seq; Transcriptional analysis; Wheat; Triticum aestivum; Azospirilum brasilense; PGPB; Cell cycle and nitrogen fixation
3.  The Herbaspirillum seropedicae SmR1 Fnr orthologs controls the cytochrome composition of the electron transport chain 
Scientific Reports  2013;3:2544.
The transcriptional regulatory protein Fnr, acts as an intracellular redox sensor regulating a wide range of genes in response to changes in oxygen levels. Genome sequencing of Herbaspirillum seropedicae SmR1 revealed the presence of three fnr-like genes. In this study we have constructed single, double and triple fnr deletion mutant strains of H. seropedicae. Transcriptional profiling in combination with expression data from reporter fusions, together with spectroscopic analysis, demonstrates that the Fnr1 and Fnr3 proteins not only regulate expression of the cbb3-type respiratory oxidase, but also control the cytochrome content and other component complexes required for the cytochrome c-based electron transport pathway. Accordingly, in the absence of the three Fnr paralogs, growth is restricted at low oxygen tensions and nitrogenase activity is impaired. Our results suggest that the H. seropedicae Fnr proteins are major players in regulating the composition of the electron transport chain in response to prevailing oxygen concentrations.
PMCID: PMC3759049  PMID: 23996052
4.  The type III secretion system is necessary for the development of a pathogenic and endophytic interaction between Herbaspirillum rubrisubalbicans and Poaceae 
BMC Microbiology  2012;12:98.
Herbaspirillum rubrisubalbicans was first identified as a bacterial plant pathogen, causing the mottled stripe disease in sugarcane. H. rubrisubalbicans can also associate with various plants of economic interest in a non pathogenic manner.
A 21 kb DNA region of the H. rubrisubalbicans genome contains a cluster of 26 hrp/hrc genes encoding for the type three secretion system (T3SS) proteins. To investigate the contribution of T3SS to the plant-bacterial interaction process we generated mutant strains of H. rubrisubalbicans M1 carrying a Tn5 insertion in both the hrcN and hrpE genes. H. rubrisulbalbicans hrpE and hrcN mutant strains of the T3SS system failed to cause the mottled stripe disease in the sugarcane susceptible variety B-4362. These mutant strains also did not produce lesions on Vigna unguiculata leaves. Oryza sativa and Zea mays colonization experiments showed that mutations in hrpE and hrcN genes reduced the capacity of H. rubrisulbalbicans to colonize these plants, suggesting that hrpE and hrcN genes are involved in the endophytic colonization.
Our results indicate that the T3SS of H. rubrisubalbicans is necessary for the development of the mottled stripe disease and endophytic colonization of rice.
PMCID: PMC3487950  PMID: 22672506
5.  Genome Sequence of the Diazotrophic Gram-Positive Rhizobacterium Paenibacillus riograndensis SBR5T 
Journal of Bacteriology  2011;193(22):6391-6392.
Paenibacillus riograndensis SBR5T, a nitrogen-fixing Gram-positive rhizobacterium isolated from a wheat field in the south of Brazil, has a great potential for agricultural applications due to its plant growth promotion effects. Here we present the draft genome sequence of P. riograndensis SBR5T. Its 7.37-Mb genome encodes determinants of the diazotrophic lifestyle and plant growth promotion, such as nitrogen fixation, antibiotic resistance, nitrate utilization, and iron uptake.
PMCID: PMC3209235  PMID: 22038959
6.  Nitrogenase Switch-Off by Ammonium Ions in Azospirillum brasilense Requires the GlnB Nitrogen Signal-Transducing Protein 
Nitrogenase activity in several diazotrophs is switched off by ammonium and reactivated after consumption. The signaling pathway to this system in Azospirillum brasilense is not understood. We show that ammonium-dependent switch-off through ADP-ribosylation of Fe protein was partial in a glnB mutant of A. brasilense but absent in a glnB glnZ double mutant. Triggering of inactivation by anaerobic conditions was not affected in either mutant. The results suggest that glnB is necessary for full ammonium-dependent nitrogenase switch-off in A. brasilense.
PMCID: PMC1214662  PMID: 16151168
7.  Swine and Poultry Pathogens: the Complete Genome Sequences of Two Strains of Mycoplasma hyopneumoniae and a Strain of Mycoplasma synoviae†  
Vasconcelos, Ana Tereza R. | Ferreira, Henrique B. | Bizarro, Cristiano V. | Bonatto, Sandro L. | Carvalho, Marcos O. | Pinto, Paulo M. | Almeida, Darcy F. | Almeida, Luiz G. P. | Almeida, Rosana | Alves-Filho, Leonardo | Assunção, Enedina N. | Azevedo, Vasco A. C. | Bogo, Maurício R. | Brigido, Marcelo M. | Brocchi, Marcelo | Burity, Helio A. | Camargo, Anamaria A. | Camargo, Sandro S. | Carepo, Marta S. | Carraro, Dirce M. | de Mattos Cascardo, Júlio C. | Castro, Luiza A. | Cavalcanti, Gisele | Chemale, Gustavo | Collevatti, Rosane G. | Cunha, Cristina W. | Dallagiovanna, Bruno | Dambrós, Bibiana P. | Dellagostin, Odir A. | Falcão, Clarissa | Fantinatti-Garboggini, Fabiana | Felipe, Maria S. S. | Fiorentin, Laurimar | Franco, Gloria R. | Freitas, Nara S. A. | Frías, Diego | Grangeiro, Thalles B. | Grisard, Edmundo C. | Guimarães, Claudia T. | Hungria, Mariangela | Jardim, Sílvia N. | Krieger, Marco A. | Laurino, Jomar P. | Lima, Lucymara F. A. | Lopes, Maryellen I. | Loreto, Élgion L. S. | Madeira, Humberto M. F. | Manfio, Gilson P. | Maranhão, Andrea Q. | Martinkovics, Christyanne T. | Medeiros, Sílvia R. B. | Moreira, Miguel A. M. | Neiva, Márcia | Ramalho-Neto, Cicero E. | Nicolás, Marisa F. | Oliveira, Sergio C. | Paixão, Roger F. C. | Pedrosa, Fábio O. | Pena, Sérgio D. J. | Pereira, Maristela | Pereira-Ferrari, Lilian | Piffer, Itamar | Pinto, Luciano S. | Potrich, Deise P. | Salim, Anna C. M. | Santos, Fabrício R. | Schmitt, Renata | Schneider, Maria P. C. | Schrank, Augusto | Schrank, Irene S. | Schuck, Adriana F. | Seuanez, Hector N. | Silva, Denise W. | Silva, Rosane | Silva, Sérgio C. | Soares, Célia M. A. | Souza, Kelly R. L. | Souza, Rangel C. | Staats, Charley C. | Steffens, Maria B. R. | Teixeira, Santuza M. R. | Urmenyi, Turan P. | Vainstein, Marilene H. | Zuccherato, Luciana W. | Simpson, Andrew J. G. | Zaha, Arnaldo
Journal of Bacteriology  2005;187(16):5568-5577.
This work reports the results of analyses of three complete mycoplasma genomes, a pathogenic (7448) and a nonpathogenic (J) strain of the swine pathogen Mycoplasma hyopneumoniae and a strain of the avian pathogen Mycoplasma synoviae; the genome sizes of the three strains were 920,079 bp, 897,405 bp, and 799,476 bp, respectively. These genomes were compared with other sequenced mycoplasma genomes reported in the literature to examine several aspects of mycoplasma evolution. Strain-specific regions, including integrative and conjugal elements, and genome rearrangements and alterations in adhesin sequences were observed in the M. hyopneumoniae strains, and all of these were potentially related to pathogenicity. Genomic comparisons revealed that reduction in genome size implied loss of redundant metabolic pathways, with maintenance of alternative routes in different species. Horizontal gene transfer was consistently observed between M. synoviae and Mycoplasma gallisepticum. Our analyses indicated a likely transfer event of hemagglutinin-coding DNA sequences from M. gallisepticum to M. synoviae.
PMCID: PMC1196056  PMID: 16077101
8.  Repressor Mutant Forms of the Azospirillum brasilense NtrC Protein 
Applied and Environmental Microbiology  2004;70(10):6320-6323.
The Azospirillum brasilense mutant strains FP8 and FP9, after treatment with nitrosoguanidine, showed a null Nif phenotype and were unable to use nitrate as their sole nitrogen source. Sequencing of the ntrC genes revealed single nucleotide mutations in the NtrC nucleotide-binding site. The phenotypes of these strains are discussed in relation to their genotypes.
PMCID: PMC522079  PMID: 15466584
9.  Genetic Characterization of Soybean Rhizobia in Paraguay† 
Applied and Environmental Microbiology  2000;66(11):5099-5103.
The soybean is an exotic plant introduced in Paraguay in this century; commercial cropping expanded after the 1970s. Inoculation is practiced in just 15 to 20% of the cropping areas, but root nodulation occurs in most sites where soybeans grow. Little is known about rhizobial diversity in South America, and no study has been performed in Paraguay until this time. Therefore, in this study, the molecular characterization of 78 rhizobial isolates from soybean root nodules, collected under field conditions in 16 sites located in the two main producing states, Alto Paraná and Itapúa, was undertaken. A high level of genetic diversity was detected by an ERIC-REP-PCR analysis, with the majority of the isolates representing unique strains. Most of the 58 isolates characterized by slow growth and alkaline reactions in a medium containing mannitol as a carbon source were clustered with strains representative of the Bradyrhizobium japonicum and Bradyrhizobium elkanii species, and the 16S ribosomal DNA (rDNA) sequences of 5 of those isolates confirmed the species identities. However, slow growers were highly polymorphic in relation to the reference strains, including five carried in commercial inoculants in neighboring countries, thus indicating that the Paraguayan isolates might represent native bradyrhizobia. Twenty isolates highly polymorphic in the ERIC-REP-PCR profiles were characterized by fast growth and acid reactions in vitro, and two of them showed high 16S rDNA identities with Rhizobium genomic species Q. However, two other fast growers showed high 16S rDNA identity with Agrobacterium spp., and both of these strains established efficient symbioses with soybean plants.
PMCID: PMC92426  PMID: 11055970
10.  l-Arabinose Metabolism in Rhizobium japonicum 
Journal of Bacteriology  1974;119(1):336-338.
l-Arabinose was metabolized through an oxidative pathway by extracts of a strain of Rhizobium japonicum. The findings showed that l-arabinose is converted into 2-keto-3-deoxy-l-arabonate, which is cleaved into glycoaldehyde and pyruvate.
PMCID: PMC245607  PMID: 4407017

Results 1-10 (10)