Consulta: subjectFacets:"Citrus variegated chlorosis"
Registros recuperados: 12
Data/hora: 02/06/2024 11:32:21

Specific amplification of iron receptor genes in Xylella fastidiosa strains from different hosts
Provedor de dados: Genetics and Molecular Biology
Autores: Pacheco,Flávia Teresa Hansen; Silva-Stenico,Maria Estela; Etchegaray,Augusto; Gomes,José Elias; Carrilho,Emanuel; Tsai,Siu Mui.
Bacterial production of siderophores may involve specific genes related to nonribosomal peptide and polyketide biosynthesis, which have not been fully identified in the genome of Xylella fastidiosa strain 9a5c. However, a search for siderophore-related genes in strain 9a5c indicated five membrane receptors, including siderophore, ferrichrome-iron and hemin receptors. All these biomolecules are thought to be associated with iron transport and utilization. Eighty isolates obtained from citrus orchards containing trees that developed citrus variegated chlorosis (CVC) were screened for siderophore production. The results demonstrated that only 10 of the isolates did not produce siderophores. Additional strains obtained from coffee, almond, mulberry, elm,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus variegated chlorosis; Plant pathogen; Iron-transportation; Pyoverdine; Enterobactin; Polyketide synthase; Peptide synthetase.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000100026

Comparative analysis of differentially expressed sequence tags of sweet orange and mandarin infected with Xylella fastidiosa
Provedor de dados: Genetics and Molecular Biology
Autores: Souza,Alessandra A. de; Takita,Marco A.; Coletta-Filho,Helvécio D.; Campos,Magnólia A.; Teixeira,Juliana E.C.; Targon,Maria Luísa P.N.; Carlos,Eduardo F.; Ravasi,Juliano F.; Fischer,Carlos N.; Machado,Marcos A.
The Citrus ESTs Sequencing Project (CitEST) conducted at Centro APTA Citros Sylvio Moreira/IAC has identified and catalogued ESTs representing a set of citrus genes expressed under relevant stress responses, including diseases such as citrus variegated chlorosis (CVC), caused by Xylella fastidiosa. All sweet orange (Citrus sinensis L. Osb.) varieties are susceptible to X. fastidiosa. On the other hand, mandarins (C. reticulata Blanco) are considered tolerant or resistant to the disease, although the bacterium can be sporadically detected within the trees, but no disease symptoms or economic losses are observed. To study their genetic responses to the presence of X. fastidiosa, we have compared EST libraries of leaf tissue of sweet orange Pêra IAC (highly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: ESTs; Citrus variegated chlorosis; Biotic stress; CitEST; Phytopathogen.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000500024

Citrus plastid-related gene profiling based on expressed sequence tag analyses
Provedor de dados: Genetics and Molecular Biology
Autores: Calsa Jr.,Tercilio; Figueira,Antonio.
Plastid-related sequences, derived from putative nuclear or plastome genes, were searched in a large collection of expressed sequence tags (ESTs) and genomic sequences from the Citrus Biotechnology initiative in Brazil. The identified putative Citrus chloroplast gene sequences were compared to those from Arabidopsis, Eucalyptus and Pinus. Differential expression profiling for plastid-directed nuclear-encoded proteins and photosynthesis-related gene expression variation between Citrus sinensis and Citrus reticulata, when inoculated or not with Xylella fastidiosa, were also analyzed. Presumed Citrus plastome regions were more similar to Eucalyptus. Some putative genes appeared to be preferentially expressed in vegetative tissues (leaves and bark) or in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus variegated chlorosis; In silico; Sweet orange; Tangerine.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000500013

Feeding site preference of Dilobopterus costalimai Young and Oncometopia facialis (Signoret) (Hemiptera: Cicadellidae) on citrus plants
Provedor de dados: Neotropical Entomology
Autores: Marucci,Rosangela C.; Lopes,João R.S.; Vendramim,José D.; Corrente,José E.
The efficiency of Xylella fastidiosa transmission by sharpshooters on citrus plants is low and varies with the vector species. The feeding behavior of the sharpshooter vector related to X. fastidiosa acquisition and inoculation is one of the probable conditioning factors in transmission efficiency. The objective of this study was to assess the behavior of two sharpshooter species, Dilobopterus costalimai Young and Oncometopia facialis (Signoret), in selection of citrus nursery trees and feeding places and to ascertain the influence of sprouting on plant attractiveness to the vectors. Free choice tests were performed with the two species in observation chambers (63 x 63 x 120 cm), releasing 40 individuals per chamber. The number of dead insects were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus sinensis; Citrus variegated chlorosis; Sharpshooter vector; Host selection.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2004000600014

GUS gene expression driven by a citrus promoter in transgenic tobacco and 'Valencia' sweet orange
Provedor de dados: Pesquisa Agropecuária Brasileira
Autores: Azevedo,Fernando Alves de; Mourão Filho,Francisco de Assis Alves; Schinor,Evandro Henrique; Paoli,Luis Gustavo de; Mendes,Beatriz Madalena Januzzi; Harakava,Ricardo; Gabriel,Dean W.; Lee,Richard F.
The objective of this work was the transformation of tobacco and 'Valencia' sweet orange with the GUS gene driven by the citrus phenylalanine ammonia-lyase (PAL) gene promoter (CsPP). Transformation was accomplished by co-cultivation of tobacco and 'Valência' sweet orange explants with Agrobacterium tumefaciens containing the binary vector CsPP-GUS/2201. After plant transformation and regeneration, histochemical analyses using GUS staining revealed that CsPP promoter preferentially, but not exclusively, conferred gene expression in xylem tissues of tobacco. Weaker GUS staining was also detected throughout the petiole region in tobacco and citrus CsPP transgenic plants.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Xylella fastidiosa; PAL; Citrus variegated chlorosis; Cultivar resistance.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2006001100008

Detection of siderophores in endophytic bacteria Methylobacterium spp. associated with Xylella fastidiosa subsp. pauca
Provedor de dados: Pesquisa Agropecuária Brasileira
Autores: Lacava,Paulo Teixeira; Silva-Stenico,Maria Estela; Araújo,Welington Luiz; Simionato,Ana Valéria Colnaghi; Carrilho,Emanuel; Tsai,Siu Mui; Azevedo,João Lúcio.
The objective of this work was to study the production of siderophores by endophytic bacteria Methylobacterium spp., which occupy the same ecological niche as Xylella fastidiosa subsp. pauca (Xfp) in citrus plants. The siderophore production of Methylobacterium strains was tested according to chromeazurol agar assay test (CAS), Csáky test (hydroxamate-type) and Arnow test (catechol-type). In addition, the ability of Xfp to use siderophores, in vitro, produced by endophytic bacteria as source of iron, was evaluated. All 37 strains of Methylobacterium spp. tested were CAS-positive for siderophore production. Methylobacterium spp. produced hydroxamate-type, but not catechol-type siderophores. In vitro growth of Xfp was stimulated by the presence of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus variegated chlorosis; Endophytes; Heterologous siderophores; Iron; Symbionts.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2008000400011

Identification of a non-host plant of Xylella fastidiosa to rear healthy sharpshooter vectors
Provedor de dados: Scientia Agricola
Autores: Marucci,Rosangela Cristina; Giustolin,Teresinha Augusta; Miranda,Marcelo Pedreira de; Miquelote,Helen; Almeida,Rodrigo Piacentini Paes de; Lopes,João Roberto Spotti.
Rearing leafhopper (Hemiptera: Cicadellidae) vectors free of Xylella fastidiosa is a requirement for studies of various aspects of vector-pathogen interactions. The selection of a plant that allows vector development but not bacterial multiplication is desirable to produce healthy vectors. In this study, two leafhopper hosts, Vernonia condensata ('boldo') and Aloysia virgata ('lixeira') were needle inoculated with citrus and coffee strains of X. fastidiosa to evaluate if these plants support pathogen colonization. The inoculated plants did not present symptoms and the pathogen was not detected by culture and PCR tests, neither soon after inoculation (7-14 days) nor later, at 1, 4, 6 and 12 months after inoculation. To obtain healthy adults of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Vernonia condensata; Citrus variegated chlorosis; Coffee leaf scorch; Sharpshooter vectors; Rearing technique.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000400010

Cloning and expression of cellulase XF-818 of Xylella fastidiosa in Escherichia Coli
Provedor de dados: Scientia Agricola
Autores: Wulff,Nelson Arno; Carrer,Helaine; Pascholati,Sérgio Florentino.
Xylella fastidiosa's genome was the first of a plant pathogen to be completely sequenced. Through comparative sequence analysis many genes were identified and, among them, several potentially involved in plant-pathogen interaction. However, the biological role of each gene should be assigned experimentally. On this regard, heterologous protein expression is a powerful tool to produce proteins from such genes, allowing their characterization. X. fastidiosa lives inside xylem vessels and eventually would degrade pit membranes from xylem cells to move radialy into the host. The identification of several putative plant cell wall degrading enzymes on X. fastidiosa genome prompted the assession of the function of such proteins. The open reading frame (ORF)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus variegated chlorosis; Cellulases; Cloning and expresssion.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000400016

Host colonization differences between citrus and coffee isolates of Xylella fastidiosa in reciprocal inoculation
Provedor de dados: Scientia Agricola
Autores: Prado,Simone de Souza; Lopes,João Roberto Spotti; Demétrio,Clarice Garcia Borges; Borgatto,Adriano Ferreti; Almeida,Rodrigo Piacentini Paes de.
Citrus variegated chlorosis (CVC) and coffee stem atrophy (CSA) are important diseases in Brazil associated with closely-related strains of Xylella fastidiosa, but little is know about host aoverlappingnd importance of citrus and coffee as inoculum sources of these strains. In this study, reciprocal-inoculation experiments were performed to determine if CVC and CSA isolates are biologically similar within citrus and coffee plants. These two hosts were mechanically inoculated with a CVC and a CSA isolate of X. fastidiosa at four concentrations ranging between10³ and 10(9) colony forming units CFU mL-1. At two, four and eight months after inoculation, the infection efficiency and bacterial populations of the isolates in each host were determined by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Citrus variegated chlorosis; Coffee leaf scorch; Inoculum concentration; Bacterial population; Epidemiology.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000300005

Incidência de Dilobopterus costalimai Young e Acrogonia citrina Marucci &amp; Cavichioli, em pomares cítricos no noroeste paranaense - DOI: 10.4025/actasciagron.v30i3.3502
Provedor de dados: Acta Scientiarum: Agronomy
Autores: Gonçalves, Alline Maria Orbolato; UEM; Molina, Rúbia de Oliveira; UEM; Nunes, William Mário de Carvalho; UEM; Zanutto, Carlos Alexandre; UEM.
As cigarrinhas das famílias Cicadellidae e Cercopidae são vetores da bactéria Xylella fastidiosa Wells, causadora da Clorose variegada dos citros. Esta doença traz sérios prejuízos à lavoura de citros no Noroeste Paranaense, e é estudada no Brasil desde 1987, quando foi descoberta pela primeira vez na região de Colina, São Paulo. Os vetores transmitem a X. fastidiosa quando se alimentam sugando a seiva do xilema, local onde a bactéria se instala, obstruindo a passagem da seiva. Este trabalho teve o objetivo de avaliar a ocorrência das cigarrinhas vetoras Dilobopterus costalimai e Acrogonia citrina em pomar comercial de citros. O experimento foi realizado no sítio “Laranjeiras I”, município de Nova Esperança, região noroeste do Paraná, no período de julho...
Palavras-chave: 5.01.00.00-9 Agronomia Cicadellidae; Citrus sinensis; Xylella fastidiosa; Clorose Variegada dos Citros Fitossanidade Cicadellidae; Citrus sinensis; Xylella fastidiosa; Citrus variegated chlorosis.
Ano: 2008
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/3502

Populational fluctuation of vectors of Xylella fastidiosa, wells in sweet orange [Citrus sinensis (L.) Osbeck] varieties of northwest Paraná State, Brazil
Provedor de dados: Brazilian Archives of Biology and Technology
Autores: Molina,Rúbia de Oliveira; Gonçalves,Aline Maria Orbolato; Zanutto,Carlos Alexandre; Nunes,William Mário de Carvalho.
The aim of the present study was to assess the population flutuation of the sharpshooters species subfamily Cicadellinae belonging to the tribes Cicadellini and Proconiini, in sweet orange [Citrus sinensis( L). Osbeck] commercial orchards of the northwest region of Paraná State , Brazil. Samplings were carried out the employing every time 24 yellow sticky cards. Identification of the species showed that the most representative were Dilobopterus costalimai of the Cicadellini tribe and Acrogonia citrina of the Proconiini tribe.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sharpshooter; Cicadellidae; Citrus variegated chlorosis.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000300007

CO2 assimilation, photosynthetic light response curves, and water relations of 'Pêra' sweet orange plants infected with Xylella fastidiosa
Provedor de dados: Brazilian Journal of Plant Physiology
Autores: Habermann,Gustavo; Machado,Eduardo Caruso; Rodrigues,João Domingos; Medina,Camilo Lázaro.
Plants with citrus variegated chlorosis (CVC), a disease caused by the xylem-limited bacteria Xylella fastidiosa, have leaves with water deficiency symptoms and are associated with decreases on the net photosynthesis and transpiration rates. Using healthy and CVC-affected 'Pêra' sweet orange plants on 'Rangpur' lime rootstock, the leaf gas exchange variables were measured with an open-gas portable photosynthesis system. All plants were watered and the leaf water potential (Yw) was measured by isopiestic thermocouple psychrometric technique. The net photosynthesis (A) vs. internal leaf CO2 concentration (A/Ci curves) was analyzed. The relative effect of stomatal resistance on photosynthesis (S%) and the estimation of carboxylation efficiency were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: A/Ci curves; Citrus variegated chlorosis; Citrus sinensis L. Osbeck; Photosynthetic photon flux density; Photosynthetic metabolism; Stomata.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202003000200003