Ativação das vias relacionadas a resistência de Citrus sinensis em resposta a interação com a bactéria Xanthomonas axonopodis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metodologia de busca para gene de componente hormonal em Xanthomonas axonopodis pv. citri, bactéria causadora do cancro cítrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção e sensibilidade de isolados de Xanthomonas axonopodis pv. citri a bacteriocinas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Resistência a cobre em Xanthomonas axonopodis pv. citri. Estudos de caracterização molecular e bioquímica de genes e proteínas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise proteômica do fitopatógeno Xanthomonas axonopodis pv. citri

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise funcional de genes de Xanthomonas axonopodis pv. citri implicados na patogênese

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Xanthomonas axonopodis pv. phaseoli em feijoeiro: sobrevivência em restos de cultura e ocorrência em sementes produzidas no estado do Paraná

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Absence of detection of xanthomonas axonopodis pv. malvacearum in cotton seeds used in the Northeast Region of Mato Grosso do Sul in a three-based crop season study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Monitoramento da expressão gênica de Xanthomonas axonopodis pv. citri em diferentes condições ambientais

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Comparison of the genomes of two Xanthomonas pathogens with differing host specificities

The genus Xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the Proteobacteria. Xanthomonas axonopodis pv. citri (Xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. Symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline(1). Xanthomonas campestris pv. campestris (Xcc) causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis(2). Xanthomonas campestris pv. campestris is grown commercially to produce the exopolysaccharide xanthan gum, which is used as a viscosifying and stabilizing agent in many industries(3). Here we report and compare the complete genome sequences of Xac and Xcc. Their distinct disease phenotypes and host ranges belie a high degree of similarity at the genomic level. More than 80% of genes are shared, and gene order is conserved along most of their respective chromosomes. We identified several groups of strain-specific genes, and on the basis of these groups we propose mechanisms that may explain the differing host specificities and pathogenic processes.

Distribution and biological role of the oligopeptide-binding protein (OppA) in Xanthomonas species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Renal and antibacterial effects induced by myotoxin I and II isolated from Bothrops jararacussu venom

Bothrops jararacussu myotoxin I (BthTx-I; Lys 49) and II (BthTX-II; Asp 49) were purified by ion-exchange chromatography and reverse phase HPLC. In this work we used the isolated perfused rat kidney method to evaluate the renal effects of B. jararacussu myotoxins I (Lys49 PLA(2)) and II (Asp49 PLA(2)) and their possible blockage by indomethacin. BthTX-1 (5 mu g/ml) and BthTX-II (5 mu g/ml) increased perfusion pressure (PP; ct(120) = 110.28+/-3.70 mmHg; BthTX I = 171.28+/-6.30* mmHg; BthTX II = 175.50+/-7.20* mmHg), renal vascular resistance (RVR; ct(120) = 5.49+/-0.54 mmHg/ml.g(-1) min(-1); BthTX I = 8.62+/-0.37* mmHg/ml g(-1) min(-1); BthTX II=8.9+/-0.36* mmHg/ml g(-1) min(-1)), urinary flow (UF; ct(120)= 0.14+/-0.01 ml g(-1) min(-1); BthTX I=0.32+/-0.05* ml g(-1) min(-1); BthTX II=0.37+/-0.01* ml g(-1) min(-1)) and glomerular filtration rate (GFR; ct(120)=0.72+/-0.10 ml g(-1) min(-1); BthTX I=0.85+/-0.13* ml g(-1) min(-1); BthTX II=1.22+/-0.28* ml g(-1) min(-1)). In contrast decreased the percent of sodium tubular transport (%TNa+; ct(120)=79,76+/-0.56; BthTX I=62.23+/-4.12*; BthTX II=70.96+/-2.93*) and percent of potassium tubular transport (%TK+;ct(120)=66.80+/-3.69; BthTX I=55.76+/-5.57*; BthTX II=50.86+/-6.16*). Indomethacin antagonized the vascular, glomerular and tubular effects promoted by BthTX I and it's partially blocked the effects of BthTX II. In this work also evaluated the antibacterial effects of BthTx-I and BthTx-II against Xanthomonas axonopodis. pv. passiflorae (Gram-negative bacteria) and we observed that both PLA2 showed antibacterial activity. Also we observed that proteins Also we observed that proteins chemically modified with 4-bromophenacyl bromide (rho-BPB) decrease significantly the antibacterial effect of both PLA(2). In conclusion, BthTx I and BthTX II caused renal alteration and presented activity antimicrobial. The indomethacin was able to antagonize totally the renal effects induced by BthTx I and partially the effects promoted by BthTx II, suggesting involvement of inflammatory mediators in the renal effects caused by myotoxins. In the other hand, other effects could be independently of the enzymatic activity of the BthTX II and the C-terminal domain could be involved in both effects promoted for PLA(2). (C) 2005 Elsevier Ltd. All rights reserved.

Biological and structural characterization of a new PLA(2) from the Crotalus durissus collilineatus venom

In the present article we report on the biological characterization and amino acid sequence of a new basic Phospholipases A(2) (PLA(2)) isolated from the Crotalus durissus collilineatus venom (Cdcolli F6), which showed the presence of 122 amino acid residues with a pI value of 8.3, molecular mass of 14 kDa and revealed an amino acid sequence identity of 80% with crotalic PLA(2)s such as Mojave B, Cdt F15, and CROATOX. This homology, however, dropped to 50% if compared to other sources of PLA(2)s such as from the Bothrops snake venom. Also, this PLA(2) induced myonecrosis, although this effect was lower than that of BthTx-I or whole crotoxin and it was able to induce a strong blockage effect on the chick biventer neuromuscular preparation, independently of the presence of the acid subunid (crotapotin). The neurotoxic effect was strongly reduced by pre-incubation with heparin or with anhydrous acetic acid and rho-BPB showed a similar reduction. The rho-BPB did not reduce significantly the myotoxic activity induced by the PLA(2), but the anhydrous acetic acid treatment and the pre-incu-bation of PLA(2) with heparin reduced significantly its effects. This protein showed a strong antimicrobial activity against Xanthomonas axonopodis passiflorae (Gram-negative), which was drastically reduced by incubation of this PLA(2) with rho-BPB, but this effect was marginally reduced after treatment with anhydrous acetic acid. Our findings here allow to speculate that basic amino acid residues on the C-terminal and molecular regions near catalytic site regions such as Calcium binding loop or rho-wing region may be involved in the binding of this PLA(2) to the molecular receptor to induce the neurotoxic effect. The bactericidal effect, however, was completely dependent on the enzymatic activity of this protein.

Purification and biological effects of a C-type lectin isolated from Bothrops moojeni

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mapas de zonas de risco de epidemias e zoneamento agroclimático para o Cancro Cítrico no Estado de São Paulo

O cancro cítrico, causado pela bactéria Xanthomonas axonopodis pv. citri Valterin et alii 1995, é uma doença conhecida mundialmente e sempre constituiu séria ameaça para a citricultura brasileira. O objetivo do presente trabalho foi analisar as condições climáticas do Estado de São Paulo e desenvolver mapas de zonas de maior risco de epidemias de cancro cítrico. Foram utilizados dados meteorológicos referentes aos anos de 2002 a 2005, os quais foram baseados no modelo de previsão desenvolvido por Campbell & Madden (4) e Hau & Kranz (10). A freqüência dos dados foi horária e quando alguma estação apresentava falha, esses eram extrapolados da estação mais próxima. Foram contabilizados os índices de favorabilidade e posteriormente calculadas as porcentagens de dias favoráveis à ocorrência da doença no período de um ano. A partir destas informações, foram gerados os mapas temáticos do Estado de São Paulo, com a distribuição espacial da porcentagem de dias favoráveis à ocorrência de cancro cítrico. A região Noroeste do Estado foi a que apresentou a maior porcentagem de dias favoráveis à ocorrência de cancro cítrico.