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Navegando DECBI - Departamento de Ciências Biológicas por Assunto "Adaptation"
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Item Analyses of seven new genomes of Xanthomonas citri pv. aurantifolii strains, causative agents of Citrus Canker B and C, show a reduced repertoire of pathogenicity-related genes.(2019) Fonseca, Natasha Peixoto; Patané, José Salvatore Leister; Varani, Alessandro de Mello; Felestrino, Érica Barbosa; Caneschi, Washington Luiz; Sanchez, Angelica Bianchini; Assis, Renata de Almeida Barbosa; Garcia, Camila Carrião Machado; Belasque Junior, José; Martins Junior, Joaquim; Facincani, Agda PaulaXanthomonas citri pv. aurantifolii pathotype B (XauB) and pathotype C (XauC) are the causative agents respectively of citrus canker B and C, diseases of citrus plants related to the better-known citrus canker A, caused by Xanthomonas citri pv. citri. The study of the genomes of strains of these related bacterial species has the potential to bring new understanding to the molecular basis of citrus canker as well as their evolutionary history. Up to now only one genome sequence of XauB and only one genome sequence of XauC have been available, both in draft status. Here we present two new genome sequences of XauB (both complete) and five new genome sequences of XauC (two complete). A phylogenomic analysis of these seven genome sequences along with 24 other related Xanthomonas genomes showed that there are two distinct and wellsupported major clades, the XauB and XauC clade and the Xanthomonas citri pv. citri clade. An analysis of 62 Type III Secretion System effector genes showed that there are 42 effectors with variable presence/absence or pseudogene status among the 31 genomes analyzed. A comparative analysis of secretion-system and surfacestructure genes showed that the XauB and XauC genomes lack several key genes in pathogenicity-related subsystems. These subsystems, the Types I and IV Secretion Systems, and the Type IV pilus, therefore emerge as important ones in helping explain the aggressiveness of the A type of citrus canker and the apparent dominance in the field of the corresponding strain over the B and C strains.Item Arsenic resistance in cultured cutaneous microbiota is associated with anuran lifestyles in the Iron Quadrangle, Minas Gerais State, Brazil.(2019) Cordeiro, Isabella Ferreira; Fonseca, Natasha Peixoto; Felestrino, Érica Barbosa; Caneschi, Washington Luiz; Pires, Maria Rita Silvério; Moreira, Leandro MarcioThe microbiota of the anuran skin contributes significantly to the maintenance and survival of these animals. In the present study, we investigated the composition of culturable microbiota on the skin of frogs from Tripui Ecological Station (TES), a locality in the Brazilian Iron Quadrangle that is naturally contaminated with arsenic. A total of 328 culturable bacterial isolates were obtained from 21 individuals belonging to seven anuran species, captured in different microenvironments within TES. The results indicate that higher numbers of culturable bacterial isolates, as well as higher resistance to arsenic and a higher capacity to produce biofilms, were associated with three frog species that had come into contact with arsenic-contaminated water during their reproductive period. These results raise the possibility that the adaptation of these anurans species to arsenicladen environments may have a direct correlation with a specialized microbiota.Item Proteome analysis of walnut bacterial blight disease.(2020) Sagawa, Cintia Helena Duarte; Assis, Renata de Almeida Barbosa; Zaini, Paulo Adriano; Wilmarth, Phillip A.; Phinney, Brett S.; Moreira, Leandro Marcio; Dandekar, Abhaya M.The interaction between the plant host, walnut (Juglans regia; Jr), and a deadly pathogen (Xanthomonas arboricola pv. juglandis 417; Xaj) can lead to walnut bacterial blight (WB), which depletes walnut productivity by degrading the nut quality. Here, we dissect this pathosystem using tandem mass tag quantitative proteomics. Walnut hull tissues inoculated with Xaj were compared to mock-inoculated tissues, and 3972 proteins were identified, of which 3296 are from Jr and 676 from Xaj. Proteins with differential abundance include oxidoreductases, proteases, and enzymes involved in energy metabolism and amino acid interconversion pathways. Defense responses and plant hormone biosynthesis were also increased. Xaj proteins detected in infected tissues demonstrate its ability to adapt to the host microenvironment, limiting iron availability, coping with copper toxicity, and maintaining energy and intermediary metabolism. Secreted proteases and extracellular secretion apparatus such as type IV pilus for twitching motility and type III secretion effectors indicate putative factors recognized by the host. Taken together, these results suggest intense degradation processes, oxidative stress, and general arrest of the biosynthetic metabolism in infected nuts. Our results provide insights into molecular mechanisms and highlight potential molecular tools for early detection and disease control strategies.