Publicações

@article{Anbumani2021,

title = {Controlled spatial organization of bacterial growth reveals key role of cell filamentation preceding Xylella fastidiosa biofilm formation},

author = {Silambarasan Anbumani and Aldeliane M. Silva and Isis G. B. Carvalho and Eduarda Regina Fischer and Mariana Silva and Antonio Augusto G. Zuben and Hernandes F. Carvalho and Alessandra A. Souza and Richard Janissen and Monica A. Cotta},

url = {https://www.nature.com/articles/s41522-021-00258-9},

doi = {10.1038/s41522-021-00258-9},

issn = {2055-5008},

year  = {2021},

date = {2021-01-01},

journal = {npj Biofilms and Microbiomes 2021 7:1},

volume = {7},

issue = {1},

pages = {1-12},

publisher = {Nature Publishing Group},

abstract = {The morphological plasticity of bacteria to form filamentous cells commonly represents an adaptive strategy induced by stresses. In contrast, for diverse human and plant pathogens, filamentous cells have been recently observed during biofilm formation, but their functions and triggering mechanisms remain unclear. To experimentally identify the underlying function and hypothesized cell communication triggers of such cell morphogenesis, spatially controlled cell patterning is pivotal. Here, we demonstrate highly selective cell adhesion of the biofilm-forming phytopathogen Xylella fastidiosa to gold-patterned SiO2 substrates with well-defined geometries and dimensions. The consequent control of both cell density and distances between cell clusters demonstrated that filamentous cell formation depends on cell cluster density, and their ability to interconnect neighboring cell clusters is distance-dependent. This process allows the creation of large interconnected cell clusters that form the structural framework for macroscale biofilms. The addition of diffusible signaling molecules from supernatant extracts provides evidence that cell filamentation is induced by quorum sensing. These findings and our innovative platform could facilitate therapeutic developments targeting biofilm formation mechanisms of X. fastidiosa and other pathogens.},

keywords = {Biofilms, Cellular microbiology, Pathogens},

pubstate = {published},

tppubtype = {article}

}

@article{Vieira2021,

title = {Xyloglucan processing machinery in Xanthomonas pathogens and its role in the transcriptional activation of virulence factors},

author = {Plinio S. Vieira and Isabela M. Bonfim and Evandro A. Araujo and Ricardo R. Melo and Augusto R. Lima and Melissa R. Fessel and Douglas A. A. Paixão and Gabriela F. Persinoti and Silvana A. Rocco and Tatiani B. Lima and Renan A. S. Pirolla and Mariana A. B. Morais and Jessica B. L. Correa and Leticia M. Zanphorlin and Jose A. Diogo and Evandro A. Lima and Adriana Grandis and Marcos S. Buckeridge and Fabio C. Gozzo and Celso E. Benedetti and Igor Polikarpov and Priscila O. Giuseppe and Mario T. Murakami},

url = {https://www.nature.com/articles/s41467-021-24277-4},

doi = {10.1038/s41467-021-24277-4},

issn = {2041-1723},

year  = {2021},

date = {2021-01-01},

journal = {Nature Communications 2021 12:1},

volume = {12},

issue = {1},

pages = {1-15},

publisher = {Nature Publishing Group},

abstract = {Xyloglucans are highly substituted and recalcitrant polysaccharides found in the primary cell walls of vascular plants, acting as a barrier against pathogens. Here, we reveal that the diverse and economically relevant Xanthomonas bacteria are endowed with a xyloglucan depolymerization machinery that is linked to pathogenesis. Using the citrus canker pathogen as a model organism, we show that this system encompasses distinctive glycoside hydrolases, a modular xyloglucan acetylesterase and specific membrane transporters, demonstrating that plant-associated bacteria employ distinct molecular strategies from commensal gut bacteria to cope with xyloglucans. Notably, the sugars released by this system elicit the expression of several key virulence factors, including the type III secretion system, a membrane-embedded apparatus to deliver effector proteins into the host cells. Together, these findings shed light on the molecular mechanisms underpinning the intricate enzymatic machinery of Xanthomonas to depolymerize xyloglucans and uncover a role for this system in signaling pathways driving pathogenesis. Xyloglucans are polysaccharides found in plant cell walls. Here, the authors describe the xyloglucan depolymerization machinery of phytopathogenic Xanthomonas bacteria, and show that sugars released by this system induce the expression of key virulence factors driving pathogenesis.},

keywords = {Bacterial physiology, Bacterial structural biology, Glycobiology, Pathogens},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {BigR is a sulfide sensor that regulates a sulfur transferase/dioxygenase required for aerobic respiration of plant bacteria under sulfide stress},

author = {Nayara Patricia Vieira De Lira and Bianca Alves Pauletti and Ana Carolina Marques and Carlos Alberto Perez and Raquel Caserta and Alessandra Alves De Souza and Aníbal Eugênio Vercesi and Adriana Franco Paes Leme and Celso Eduardo Benedetti},

url = {https://www.nature.com/articles/s41598-018-21974-x},

doi = {10.1038/s41598-018-21974-x},

issn = {2045-2322},

year  = {2018},

date = {2018-01-01},

journal = {Scientific Reports 2018 8:1},

volume = {8},

issue = {1},

pages = {1-13},

publisher = {Nature Publishing Group},

abstract = {To cope with toxic levels of H2S, the plant pathogens Xylella fastidiosa and Agrobacterium tumefaciens employ the bigR operon to oxidize H2S into sulfite. The bigR operon is regulated by the transcriptional repressor BigR and it encodes a bifunctional sulfur transferase (ST) and sulfur dioxygenase (SDO) enzyme, Blh, required for H2S oxidation and bacterial growth under hypoxia. However, how Blh operates to enhance bacterial survival under hypoxia and how BigR is deactivated to derepress operon transcription is unknown. Here, we show that the ST and SDO activities of Blh are in vitro coupled and necessary to oxidize sulfide into sulfite, and that Blh is critical to maintain the oxygen flux during A. tumefaciens respiration when oxygen becomes limited to cells. We also show that H2S and polysulfides inactivate BigR leading to operon transcription. Moreover, we show that sulfite, which is produced by Blh in the ST and SDO reactions, is toxic to Citrus sinensis and that X. fastidiosa-infected plants accumulate sulfite and higher transcript levels of sulfite detoxification enzymes, suggesting that they are under sulfite stress. These results indicate that BigR acts as a sulfide sensor in the H2S oxidation mechanism that allows pathogens to colonize plant tissues where oxygen is a limiting factor.},

keywords = {Biotic, Pathogens},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {BigR is a sulfide sensor that regulates a sulfur transferase/dioxygenase required for aerobic respiration of plant bacteria under sulfide stress},

author = {Nayara Patricia Vieira De Lira and Bianca Alves Pauletti and Ana Carolina Marques and Carlos Alberto Perez and Raquel Caserta and Alessandra Alves De Souza and Aníbal Eugênio Vercesi and Adriana Franco Paes Leme and Celso Eduardo Benedetti},

url = {https://www.nature.com/articles/s41598-018-21974-x},

doi = {10.1038/s41598-018-21974-x},

issn = {2045-2322},

year  = {2018},

date = {2018-01-01},

journal = {Scientific Reports 2018 8:1},

volume = {8},

issue = {1},

pages = {1-13},

publisher = {Nature Publishing Group},

abstract = {To cope with toxic levels of H2S, the plant pathogens Xylella fastidiosa and Agrobacterium tumefaciens employ the bigR operon to oxidize H2S into sulfite. The bigR operon is regulated by the transcriptional repressor BigR and it encodes a bifunctional sulfur transferase (ST) and sulfur dioxygenase (SDO) enzyme, Blh, required for H2S oxidation and bacterial growth under hypoxia. However, how Blh operates to enhance bacterial survival under hypoxia and how BigR is deactivated to derepress operon transcription is unknown. Here, we show that the ST and SDO activities of Blh are in vitro coupled and necessary to oxidize sulfide into sulfite, and that Blh is critical to maintain the oxygen flux during A. tumefaciens respiration when oxygen becomes limited to cells. We also show that H2S and polysulfides inactivate BigR leading to operon transcription. Moreover, we show that sulfite, which is produced by Blh in the ST and SDO reactions, is toxic to Citrus sinensis and that X. fastidiosa-infected plants accumulate sulfite and higher transcript levels of sulfite detoxification enzymes, suggesting that they are under sulfite stress. These results indicate that BigR acts as a sulfide sensor in the H2S oxidation mechanism that allows pathogens to colonize plant tissues where oxygen is a limiting factor.},

keywords = {Biotic, Pathogens},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {BigR is a sulfide sensor that regulates a sulfur transferase/dioxygenase required for aerobic respiration of plant bacteria under sulfide stress},

author = {Nayara Patricia Vieira De Lira and Bianca Alves Pauletti and Ana Carolina Marques and Carlos Alberto Perez and Raquel Caserta and Alessandra Alves De Souza and Aníbal Eugênio Vercesi and Adriana Franco Paes Leme and Celso Eduardo Benedetti},

url = {https://www.nature.com/articles/s41598-018-21974-x},

doi = {10.1038/s41598-018-21974-x},

issn = {2045-2322},

year  = {2018},

date = {2018-01-01},

journal = {Scientific Reports 2018 8:1},

volume = {8},

issue = {1},

pages = {1-13},

publisher = {Nature Publishing Group},

abstract = {To cope with toxic levels of H2S, the plant pathogens Xylella fastidiosa and Agrobacterium tumefaciens employ the bigR operon to oxidize H2S into sulfite. The bigR operon is regulated by the transcriptional repressor BigR and it encodes a bifunctional sulfur transferase (ST) and sulfur dioxygenase (SDO) enzyme, Blh, required for H2S oxidation and bacterial growth under hypoxia. However, how Blh operates to enhance bacterial survival under hypoxia and how BigR is deactivated to derepress operon transcription is unknown. Here, we show that the ST and SDO activities of Blh are in vitro coupled and necessary to oxidize sulfide into sulfite, and that Blh is critical to maintain the oxygen flux during A. tumefaciens respiration when oxygen becomes limited to cells. We also show that H2S and polysulfides inactivate BigR leading to operon transcription. Moreover, we show that sulfite, which is produced by Blh in the ST and SDO reactions, is toxic to Citrus sinensis and that X. fastidiosa-infected plants accumulate sulfite and higher transcript levels of sulfite detoxification enzymes, suggesting that they are under sulfite stress. These results indicate that BigR acts as a sulfide sensor in the H2S oxidation mechanism that allows pathogens to colonize plant tissues where oxygen is a limiting factor.},

keywords = {Biotic, Pathogens},

pubstate = {published},

tppubtype = {article}

}