scholarly journals Coffee Leaf Scorch Bacterium: Axenic Culture, Pathogenicity, and Comparison with Xylella fastidiosa of Citrus

Plant Disease ◽  
1998 ◽  
Vol 82 (1) ◽  
pp. 94-97 ◽  
Author(s):  
J. E. O. de Lima ◽  
V. S. Miranda ◽  
J. S. Hartung ◽  
R. H. Brlansky ◽  
A. Coutinho ◽  
...  
Keyword(s):  
Shoot Growth ◽  
Xylella Fastidiosa ◽  
Polymerase Chain Reaction Amplification ◽  
Axenic Culture ◽  
Enzyme Linked Immunosorbent Assay ◽  
Leaf Scorch ◽  
Mature Leaves ◽  
Reaction Amplification ◽  
Polymerase Chain ◽  
Cultured Bacteria

Symptoms of coffee leaf scorch (CLS) appear on young flushes of field plants as large marginal and apical scorched areas on recently mature leaves. Affected leaves drop, shoot growth is stunted, and apical leaves are small and chlorotic. Symptoms may progress to shoot dieback. Only scorched leaves which could not be related to other known agents consistently contained bacteria and bacterial agglomerates when observed with light microscopy. Only plants with these symptoms were positive in enzyme-linked immunosorbent assay (ELISA) tests using antiserum to Xylella fastidiosa Wells et al. The bacterium Xylella fastidiosa Wells et al. was isolated in November 1995 from coffee (Coffea arabica) leaves with scorch symptoms on supplemented periwinkle wilt medium. Colonies were circular, dome-shaped, white, and 0.5 to 1.5 mm in diameter. Two of 10 young coffee seedlings stem-inoculated with a suspension of the isolated X. fastidiosa in January 1996 showed leaf scorch symptoms 3 to 5 months later, contained bacteria in xylem extracts, and reacted positively in ELISA using antiserum to the citrus variegated chlorosis (CVC) strain of X. fastidiosa. ELISA-positive bacteria were reisolated from this plant. None of the symptomless plants, including controls, revealed bacteria on microscopic examinations, ELISA, or isolation attempts. Antisera developed against cultured bacteria from both CLS and CVC plants reacted positively against plant extracts of both diseases in dot immunobinding assays (DIBA). The level of detection was about 5 × 105 bacteria ml-1 for both homologous and heterologous reactions. The polymerase chain reaction amplification products produced by CLS and CVC strains of X. fastidiosa were indistinguishable. Geographical distribution of these strains is not the same. CLS is widespread and usually occurs if coffee is adjacent to CVC-affected citrus. However, CVC does not always occur when citrus is grown adjacent to CLS-affected coffee. The bacteria are closely related, if not identical.

Detection of IncP replicon-specific regions in DNA from Antarctic microbiota

2007 ◽  
Vol 2 (3) ◽  
pp. 378-384 ◽  
Author(s):  
Tatiana Imperio ◽  
Roberto Bargagli ◽  
Laura Marri
Keyword(s):  
Polymerase Chain Reaction Amplification ◽  
Broad Host Range ◽  
Limited Information ◽  
Broad Host Range Plasmid ◽  
Victoria Land ◽  
Pcr Products ◽  
Total Community ◽  
Reaction Amplification ◽  
Polymerase Chain ◽  
Cultured Bacteria

AbstractPlasmids capable of horizontal transfer contribute to the adaptability of bacteria, as they may provide genes that enable their hosts to cope with different selective pressures. Only limited information is available on plasmids from Antarctic habitats, and up until now surveys have only used traditional methods of endogenous plasmid isolation. The method based on primer systems, designed on the basis of published sequences for plasmids from different incompatibility (Inc) groups, is appropriate to detect the replicon-specific regions of corresponding plasmids in cultured bacteria, or in total community DNA, which share sufficient DNA similarity with reference plasmids at the amplified regions. In this study, we applied broad-host-range plasmid-specific primers to DNA from microbial samples collected at six different locations in Northern Victoria Land (Antarctica). DNA preparations were used as targets for PCR (polymerase chain reaction) amplification with primers for the IncP (trfA2) and IncQ (oriV ) groups. PCR products were Southern blotted and hybridized with PCR-derived probes for trfA2 and oriV regions. This approach detected the occurrence of IncP-specific sequences in eight out of fifteen DNA samples, suggesting a gene-mobilizing capacity within the original habitats.

scholarly journals A Survey for Strains of Xylella fastidiosa in Citrus Affected by Citrus Variegated Chlorosis and Citrus Blight in Brazil

Plant Disease ◽  
1997 ◽  
Vol 81 (10) ◽  
pp. 1196-1198 ◽  
Author(s):  
M. J. G. Beretta ◽  
G. A. Barthe ◽  
T. L. Ceccardi ◽  
R. F. Lee ◽  
K. S. Derrick
Keyword(s):  
Xylella Fastidiosa ◽  
Polymerase Chain Reaction Amplification ◽  
Chain Reaction ◽  
Citrus Variegated Chlorosis ◽  
Mulberry Leaf ◽  
Reaction Amplification ◽  
Citrus Blight ◽  
Dna Fragment ◽  
Polymerase Chain ◽  
Consensus Primers

Polymerase chain reaction amplification of DNA from various strains of Xylella fastidiosa with tRNA consensus primers produced three different fingerprint groups. The citrus variegated chlorosis (CVC) and mulberry leaf scorch strains were unique and readily separated from each other and all other strains tested. Internal primers were designed based on the sequence of a DNA fragment unique to the CVC strain. An assay was developed with a mixture of these primers and those reported to detect 18 strains of X. fastidiosa. The assay was used to survey citrus in Brazil. The strain identified to be the cause of CVC was found in constant association with trees with CVC symptoms. On occasion, trees with no symptoms were found to have the CVC strain; this was presumably due to presymptomatic infections. No other strains were found in this survey, and X. fastidiosa was not associated with citrus blight.

scholarly journals Coffee Leaf Scorch Caused by a Strain of Xylella fastidiosa from Citrus

Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 501-505 ◽  
Author(s):  
W.-B. Li ◽  
W. D. Pria ◽  
D. C. Teixeira ◽  
V. S. Miranda ◽  
A. J. Ayres ◽  
...  
Keyword(s):  
Xylella Fastidiosa ◽  
Leaf Size ◽  
Coffea Canephora ◽  
Enzyme Linked Immunosorbent Assay ◽  
Lateral Shoot ◽  
Disease Symptoms ◽  
Citrus Variegated Chlorosis ◽  
Leaf Scorch ◽  
Coffee Plants ◽  
Polymerase Chain

Citrus variegated chlorosis (CVC) and coffee leaf scorch (CLS) are two economically important diseases in Brazil caused by the bacterium Xylella fastidiosa. Strains of the bacterium isolated from the two plant hosts are very closely related, and the two diseases share sharpshooter insect vectors. In order to determine if citrus strains of X. fastidiosa could infect coffee and induce CLS disease, plant inoculations were performed. Plants of coffee, Coffea arabica ‘Mundo Novo’, grafted on Coffea canephora var. robusta ‘Apuatão 2258’ were mechanically inoculated with triply cloned strains of X. fastidiosa isolated from diseased coffee and citrus. Three months postinoculation, 5 of the 10 plants inoculated with CLS-X. fastidiosa and 1 of the 10 plants inoculated with CVC-X. fastidiosa gave positive enzyme-linked immunosorbent assay (ELISA) and/or polymerase chain reaction (PCR). Eight months postinoculation, another six plants inoculated with CVC-X. fastidiosa gave positive PCR results. The two X. fastidiosa strains were isolated from the inoculated plants and showed the same characteristics as the original clones by microscopy, ELISA, and PCR. None of the plants inoculated with sterile periwinkle wilt (PW) medium as controls gave positive reactions in diagnostic tests, and none developed disease symptoms. Six months postinoculation, seven plants inoculated with CLS-X. fastidiosa and eight inoculated with CVC-X. fastidiosa began to develop characteristic CLS symptoms, including apical and marginal leaf scorch, defoliation, and reductions of internode length, leaf size, and plant height, terminal clusters of small chlorotic and deformed leaves, and lateral shoot dieback. We have demonstrated that X. fastidiosa from citrus plants is pathogenic for coffee plants. This has important consequences for the management of CLS disease and has implications for the origin of citrus variegated chlorosis disease.

Polymerase chain reaction amplification and typing of rotavirus in environmental samples

1995 ◽  
Vol 31 (5-6) ◽  
pp. 371-374 ◽  
Author(s):  
R. Gajardo ◽  
R. M. Pintó ◽  
A. Bosch
Keyword(s):  
Polymerase Chain Reaction ◽  
Environmental Samples ◽  
Polymerase Chain Reaction Amplification ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Group A ◽  
Reaction Amplification ◽  
Stool Specimens ◽  
Polymerase Chain

A reverse transcription polymerase chain reaction (RT-PCR) assay is described that has been developed for the detection and serotyping of group A rotavirus in stool specimens and concentrated and non-concentrated sewage specimens.

scholarly journals Molecular Characterization of hobo-Mediated Inversions in Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 647-656
Author(s):  
William B Eggleston ◽  
Nac R Rim ◽  
Johng K Lim
Keyword(s):  
X Chromosome ◽  
Polymerase Chain Reaction Amplification ◽  
Polytene Chromosomes ◽  
Chromosomal Inversions ◽  
Hobo Element ◽  
Reaction Amplification ◽  
Notch Locus ◽  
Polymerase Chain

Abstract The structure of chromosomal inversions mediated by hobo transposable elements in the Uc-1 X chromosome was investigated using cytogenetic and molecular methods. Uc-1 contains a phenotypically silent hobo element inserted in an intron of the Notch locus. Cytological screening identified six independent Notch mutations resulting from chromosomal inversions with one breakpoint at cytological position 3C7, the location of Notch. In situ hybridization to salivary gland polytene chromosomes determined that both ends of each inversion contained hobo and Notch sequences. Southern blot analyses showed that both breakpoints in each inversion had hobo-Notch junction fragments indistinguishable in structure from those present in the Uc-1 X chromosome prior to the rearrangements. Polymerase chain reaction amplification of the 12 hobo-Notch junction fragments in the six inversions, followed by DNA sequence analysis, determined that each was identical to one of the two hobo-Notch junctions present in Uc-1. These results are consistent with a model in which hobo-mediated inversions result from homologous pairing and recombination between a pair of hobo elements in reverse orientation.

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