328 research outputs found

    Identification of New Genes Related to Virulence of Xanthomonas axonopodis Pv. Citri during Citrus Host Interactions

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    A mutant library of the bacterium Xanthomonas citri subsp. citri strain 306 pathotype A (Xac), the causative agent of most aggressive Asiatic type A citrus canker, was screened regarding altered canker symptoms after inoculations into Citrus sinensis and Citrus limonia host leaves. Twenty-six mutants have shown phenotypic virulence changes and have respectively knocked out gene identified by sequencing. In vivo growth curves were obtained for nine mutants to quantify how the mutations could affect pathogen's adaptability to growth inside and attack host plant infected tissue. Among identified genes in mutated strains, we could find those that until now had not been reported as being involved in Xac adaptation and/or virulence, such as predicted to encode for xylose repressor-like protein (XAC Delta xylR), Fe-S oxidoredutase (XAC Delta aslB), helicase IV (XAC Delta helD), ubiquinol cytochrome c oxidoreductase iron-sulfur subunit (XAC Delta petA), chromosome partitioning protein (XAC Delta parB) and cell division protein FtsB (XAC Delta ftsB), in addition to genes predicted to encode for hypothetical proteins. The new genes found in this study as being relevant to adaptation and virulence, improve the understanding of Xac fitness during citrus plant attack and canker symptoms development.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESPCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior-CAPESCNPqFundo de Defesa da Citricultura (FUNDECITRUS)CAPESFUNDECITRUSFAPESPSao Paulo State Univ UNESP, Fac Agr Sci & Vet, Dept Technol, Jaboticabal, SP, BrazilCitriculture Res Ctr Sylvio Moreira IAC Campinas, Campinas, SP, BrazilUniv Fed Ouro Preto, Inst Exact & Biol Sci, Dept Biol Sci, Ouro Preto, MG, BrazilUniv Fed Ouro Preto, Res Ctr Biol Sci NUPEB, Inst Exact & Biol Sci, Dept Biol Sci, Ouro Preto, MG, BrazilSao Paulo State Univ UNESP, Fac Agr Sci & Vet, Plant Hlth Dept, Jaboticabal, SP, BrazilFed Univ Sao Paulo UNIFESP, Dept Biol Sci, Diadema, SP, BrazilFed Univ Sao Paulo UNIFESP, Dept Biol Sci, Diadema, SP, BrazilFAPESP: 04/02006-7Web of Scienc

    CYTOTOXICITY, ANTI-POLIOVIRUS ACTIVITY AND IN SILICO BIOLOGICAL EVALUATION OF CONSTITUENTS FROM MAYTENUS GONOCLADA (CELASTRACEAE)

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    Objective: The in silico free access web tools PASS online and ChemMapper were used to predict potential biological activities of compounds 1 to 8 isolated from Maytenus gonoclada (Celastraceae). The constituents 4'-O-methylepigalocatequin (6), tingenone (7) and proanthocyanidin A (8), and ethanolic extracts were subjected to in vitro cytotoxicity using VERO cells and anti-Poliovirus assays. Methods: QSAR and molecular superposition, correlating the average number of pharmacophores were used in the prediction studies. Cellular line VERO ATCC CCL-81 was used to determine anti-Poliovirus effect, observed by colorimetric (MTT) method. The annexing V/propidium iodide assay was used to determine the occurrence of apoptosis in the cytotoxicity assays. Results: The experimental results found for constituents 6-8 were in accordance with observed data obtained through PASS online and ChemMapper simulation. Conclusion: Compound 7 showed higher cytotoxic and apoptosis induction properties, and 6 and 8 presented anti-Poliovirus activity

    Antibacterial Activity of Root-end Filling Materials

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    Svrha istraživanja bila je ocijeniti i usporediti antibakterijsku učinkovitost pet retrogradnih punila korijenskih kanala. Materijal i metode: Metodom difuzije u agru ocijenjena je zona inhibicije bakterijskog rasta na podlozi pet retrogradnih punila korijenskih kanala: Pro Root MTA, cementa Portland, Super-EBA, IRM-a, Sealera 26 te amalgama. Za ciljane mikroorganizme bilo je odabrano pet anaeroba (Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum, Propionibacterium acnes i Eubacterium saburreum) te dva fakultativna (Actinomyces viscosus i Enterococcus faecalis). Rezultati: Sealer 26 postigao je najveću inhibiciju rasta. Punila IRM i Super-EBA spriječila su rast samo Porphyromonas gingivalis, ali učinak je bio znatno slabiji u usporedbi s djelovanjem Sealera 26. Kao neučinkovita antibakterijska sredstva pokazali su se MTA, cement Portland i amalgam. Zaključak: Rezultati istraživanja potvrdili su da Sealer 26 ima najjače antibakterijsko djelovanje u usporedbi s ostalim često upotrebljavanim apikalnim punilima korijenskih kanala.Purpose: The present study was undertaken to evaluate and compare the antibacterial effectiveness of five root-end filling materials. Material and methods: The agar diffusion method was employed to evaluate the inhibition zone provided by the following root-end filling materials: Pro Root MTA, Portland cement, Super-EBA, IRM, Sealer 26, and silver amalgam. The target microorganisms included five anaerobic bacterial species (Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum, Propionibacterium acnes and Eubacterium saburreum) and two facultative bacterial species (Actinomyces viscosus and Enterococcus faecalis). Results: Sealer 26 demonstrated the largest inhibitory effects on all species tested. IRM and Super-EBA were inhibitory only to P. gingivalis, but this effect was far less pronounced as compared to Sealer 26. MTA, Portland cement, and amalgam proved ineffective against all species tested. Conclusion: These findings revealed that Sealer 26 has more pronounced antibacterial effects when compared to other commonly used root-end filling materials

    A mild and efficient method for the preparation of 3-(2'-Aminoaryl)pyrazoles from 4-chloroquinolines

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    We describe a mild and efficient method for the formation of 3-(2'-aminoaryl)pyrazoles in excellent yields from reactions of 4-chloroquinolines with hydrazine. These heterocyclic ring opening reactions occur under much milder conditions then previously described

    BRS 400 e BRS 401: novas cultivares de mandioca de mesa com raízes de polpa rosada.

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    A mandioca, além de ser uma excelente fonte de carboidratos para a alimentação humana, pode se tornar uma fonte de licopeno nas raízes de coloração rosada (Carvalho et al., 2011). O licopeno é um antioxidante, que apresenta ação no combate ao envelhecimento precoce e na prevenção do câncer de próstata (Shami; Moreira, 2004). Nesse contexto, a possibilidade de se disponibilizar raízes de mandioca com licopeno é uma das formas de melhorar a nutrição da população e de agregar valor às cultivares destinadas ao consumo humano. O programa de melhoramento genético de mandioca da Embrapa Cerrados está focado no desenvolvimento de cultivares específicas para uso culinário (cozida, frita, chips, mandioca palito, pré-cozida, massas, entre outras). As cultivares devem apresentar baixa capacidade de gerarem ácido cianídrico (HCN), ou seja, apresentarem teores do glicosídio linamarina inferiores a 100 mg para cada quilograma nas raízes de reserva frescas, produtividades elevadas de raízes com boas qualidades sensoriais e culinárias e também com maior tolerância/resistência a pragas e a doenças. Tudo isso aliado à aceitação por parte dos produtores e consumidores de mandioca. Com o objetivo de ofertar cultivares de mandioca de mesa com coloração da polpa das raízes rosadas adaptadas às condições do Distrito Federal, a Embrapa disponibiliza as cultivares BRS 400 e BRS 401 aos produtores da região.bitstream/item/221840/1/ComTec-185-Eduardo-Alano-web.pd

    BRS 396, BRS 397, BRS 398 e BRS 399: novas cultivares de mandioca de mesa com coloração da polpa das raízes amarela e creme.

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    Os consumidores de mandioca de mesa (cozidas, fritas, chips, mandioca palito, pré-cozida, massas, entre outras) estão se tornando cada vez mais exigentes quanto aos aspectos organolépticos, sanitários e nutricionais. Essa mudança no perfil forçou os produtores a uma rápida incorporação de tecnologias modernas de cultivo. Nesse sentido, o programa de melhoramento genético de mandioca da Embrapa Cerrados foca no desenvolvimento de cultivares de mandioca de mesa com baixos teores de HCN nas raízes, mais nutritivas, precoces, produtivas, adaptadas ao plantio mecanizado e ao cultivo irrigado, resistentes às principais pragas e doenças e com boas qualidades culinárias. Tudo isso aliado à boa aceitação por parte dos produtores e consumidores de mandioca.bitstream/item/221841/1/ComTec-186-Eduardo-Alano-Web.pd

    Proteomics-based identification of differentially abundant proteins reveals adaptation mechanisms of Xanthomonas citri subsp citri during Citrus sinensis infection

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    Background: Xanthomonas citri subsp. citri (Xac) is the causal agent of citrus canker. A proteomic analysis under in planta infectious and non-infectious conditions was conducted in order to increase our knowledge about the adaptive process of Xac during infection. Results: For that, a 2D-based proteomic analysis of Xac at 1, 3 and 5 days after inoculation, in comparison to Xac growth in NB media was carried out and followed by MALDI-TOF-TOF identification of 124 unique differentially abundant proteins. Among them, 79 correspond to up-regulated proteins in at least one of the three stages of infection. Our results indicate an important role of proteins related to biofilm synthesis, lipopolysaccharides biosynthesis, and iron uptake and metabolism as possible modulators of plant innate immunity, and revealed an intricate network of proteins involved in reactive oxygen species adaptation during Plants'Oxidative Burst response. We also identified proteins previously unknown to be involved in Xac-Citrus interaction, including the hypothetical protein XAC3981. A mutant strain for this gene has proved to be non-pathogenic in respect to classical symptoms of citrus canker induced in compatible plants. Conclusions: This is the first time that a protein repertoire is shown to be active and working in an integrated manner during the infection process in a compatible host, pointing to an elaborate mechanism for adaptation of Xac once inside the plant.Fundacao de Amparo a Pesquisa do Estado de Sao PauloFundacao de Amparo a Pesquisa do Estado de Minas GeraisBIGA grant-CAPESUniv Fed Ouro Preto, Inst Ciencias Exatas & Biol, Dept Ciencias Biol DECBI, Ouro Preto, MG, BrazilUniv Fed Ouro Preto, Nucleo Pesquisas Ciencias Biol NUPEB, Ouro Preto, MG, BrazilUniv Fed Rio de Janeiro, Inst Quim, Dept Bioquim DBq, Rio De Janeiro, RJ, BrazilUniv Estadual Paulista, UNESP, Dept Tecnol, Fac Ciencias Agr & Vet Jaboticabal, Jaboticabal, SP, BrazilUniv Estadual Campinas, UNICAMP, Inst Quim, Campinas, SP, BrazilUniv Sao Paulo, Inst Quim, Dept Bioquim, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Ciencias Biol, Diadema, SP, BrazilVirginia Tech, Biocomplex Inst, Blacksburg, VA USAUniv Sao Paulo, Inst Quim, Dept Bioquim, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Ciencias Biol, Diadema, SP, BrazilCAPESFAPESP: 04/02006-7Fundacao de Amparo a Pesquisa do Estado de Minas Gerais: CBB-APQ-04425-10BIGA grant-CAPES: 3385/2013Web of Scienc
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