scholarly journals Expression of the strA-strB streptomycin resistance genes in Pseudomonas syringae and Xanthomonas campestris and characterization of IS6100 in X. campestris.

1995 ◽  
Vol 61 (8) ◽  
pp. 2891-2897 ◽  
Author(s):  
G W Sundin ◽  
C L Bender
HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 547a-547
Author(s):  
Geunhwa Jung ◽  
James Nienhuis ◽  
Dermot P. Coyne ◽  
H.M. Ariyarathne

Common bacterial blight (CBB), bacterial brown spot (BBS), and halo blight (HB), incited by the bacterial pathogens Xanthomonas campestris pv. phaseoli (Smith) Dye, Pseodomonas syringae pv. syringa, and Pseudomonas syringae pv. phaseolicola, respectively are important diseases of common bean. In addition three fungal pathogens, web blight (WB) Thanatephorus cucumeris, rust Uromyces appendiculatus, and white mold (WM) Sclerotinia sclerotiorum, are also destructive diseases attacking common bean. Bean common mosaic virus is also one of most major virus disease. Resistance genes (QTLs and major genes) to three bacterial (CBB, BBS, and HB), three fungal (WB, rust, and WM), and one viral pathogen (BCMV) were previously mapped in two common bean populations (BAC 6 × HT 7719 and Belneb RR-1 × A55). The objective of this research was to use an integrated RAPD map of the two populations to compare the positions and effect of resistance QTL in common bean. Results indicate that two chromosomal regions associated with QTL for CBB resistance mapped in both populations. The same chromosomal regions associated with QTL for disease resistance to different pathogens or same pathogens were detected in the integrated population.


2005 ◽  
Vol 71 (12) ◽  
pp. 8284-8291 ◽  
Author(s):  
Huseyin Basim ◽  
Gerald V. Minsavage ◽  
Robert E. Stall ◽  
Jaw-Fen Wang ◽  
Savita Shanker ◽  
...  

ABSTRACT We characterized the copper resistance genes in strain XvP26 of Xanthomonas campestris pv. vesicatoria, which was originally isolated from a pepper plant in Taiwan. The copper resistance genes were localized to a 7,652-bp region which, based on pulsed-field gel electrophoresis and Southern hybridization, was determined to be located on the chromosome. These genes hybridized only weakly, as determined by Southern analysis, to other copper resistance genes in Xanthomonas and Pseudomonas strains. We identified five open reading frames (ORFs) whose products exhibited high levels of amino acid sequence identity to the products of previously reported copper genes. Mutations in ORF1, ORF3, and ORF4 removed copper resistance, whereas mutations in ORF5 resulted in an intermediate copper resistance phenotype and insertions in ORF2 had no effect on resistance conferred to a copper-sensitive recipient in transconjugant tests. Based on sequence analysis, ORF1 was determined to have high levels of identity with the CopR (66%) and PcoR (63%) genes in Pseudomonas syringae pv. tomato and Escherichia coli, respectively. ORF2 and ORF5 had high levels of identity with the PcoS gene in E. coli and the gene encoding a putative copper-containing oxidoreductase signal peptide protein in Sinorhizobium meliloti, respectively. ORF3 and ORF4 exhibited 23% identity to the gene encoding a cation efflux system membrane protein, CzcC, and 62% identity to the gene encoding a putative copper-containing oxidoreductase protein, respectively. The latter two ORFs were determined to be induced following exposure to low concentrations of copper, while addition of Co, Cd, or Zn resulted in no significant induction. PCR analysis of 51 pepper and 34 tomato copper-resistant X. campestris pv. vesicatoria strains collected from several regions in Taiwan between 1987 and 2000 and nine copper-resistant strains from the United States and South America showed that successful amplification of DNA was obtained only for strain XvP26. The organization of this set of copper resistance genes appears to be uncommon, and the set appears to occur rarely in X. campestris pv. vesicatoria.


1999 ◽  
Vol 181 (4) ◽  
pp. 1220-1228 ◽  
Author(s):  
Jiann-Hwa Chen ◽  
Yu-Ying Hsieh ◽  
Su-Lian Hsiau ◽  
Ta-Chun Lo ◽  
Chen-Chun Shau

ABSTRACT Thirty-two plasmid insertion mutants were independently isolated from two strains of Xanthomonas campestris pv. campestris in Taiwan. Of the 32 mutants, 14 (44%), 8 (25%), and 4 (12%) mutants resulted from separate insertions of an IS3 family member, IS476, and two new insertion sequences (IS), IS1478 and IS1479. While IS1478does not have significant sequence homology with any IS elements in the EMBL/GenBank/DDBJ database, IS1479 demonstrated 73% sequence homology with IS1051 in X. campestrispv. dieffenbachiae, 62% homology with IS52 inPseudomonas syringae pv. glycinea, and 60% homology with IS5 in Escherichia coli. Based on the predicted transposase sequences as well as the terminal nucleotide sequences, IS1478 by itself constitutes a new subfamily of the widespread IS5 family, whereas IS1479, along with IS1051, IS52, and IS5, belongs to the IS5 subfamily of the IS5 family. All but one of the IS476 insertions had duplications of 4 bp at the target sites without sequence preference and were randomly distributed. An IS476 insertion carried a duplication of 952 bp at the target site. A model for generating these long direct repeats is proposed. Insertions of IS1478 and IS1479, on the other hand, were not random, and IS1478 and IS1479 each showed conservation of PyPuNTTA and PyTAPu sequences (Py is a pyrimidine, Pu is a purine, and N is any nucleotide) for duplications at the target sites. The results of Southern blot hybridization analysis indicated that multiple copies of IS476, IS1478, and IS1479 are present in the genomes of all seven X. campestris pv. campestris strains tested and several X. campestrispathovars.


2010 ◽  
Vol 36 (1) ◽  
pp. 109-114 ◽  
Author(s):  
Hong ZHANG ◽  
Zhi-Long REN ◽  
Yin-Gang HU ◽  
Chang-You WANG ◽  
Wan-Quan JI

2014 ◽  
Vol 81 (1) ◽  
pp. 432-440 ◽  
Author(s):  
T. Sotelo ◽  
M. Lema ◽  
P. Soengas ◽  
M. E. Cartea ◽  
P. Velasco

ABSTRACTGlucosinolates (GSLs) are secondary metabolites found inBrassicavegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about theirin vitrobiocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enrichedBrassicacrops on suppressingin vitrogrowth of two bacterial (Xanthomonas campestrispv. campestris andPseudomonas syringaepv. maculicola) and two fungal (AlternariabrassicaeandSclerotiniascletoriorum)Brassicapathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of differentBrassicaspecies, have potential to inhibit pathogen growth and offer new opportunities to study the use ofBrassicacrops in biofumigation for the control of multiple diseases.


Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 401-412 ◽  
Author(s):  
Randall F Warren ◽  
Peter M Merritt ◽  
Eric Holub ◽  
Roger W Innes

Abstract The RPS5 disease resistance gene of Arabidopsis mediates recognition of Pseudomonas syringae strains that possess the avirulence gene avrPphB. By screening for loss of RPS5-specified resistance, we identified five pbs (avrPphB susceptible) mutants that represent three different genes. Mutations in PBS1 completely blocked RPS5-mediated resistance, but had little to no effect on resistance specified by other disease resistance genes, suggesting that PBS1 facilitates recognition of the avrPphB protein. The pbs2 mutation dramatically reduced resistance mediated by the RPS5 and RPM1 resistance genes, but had no detectable effect on resistance mediated by RPS4 and had an intermediate effect on RPS2-mediated resistance. The pbs2 mutation also had varying effects on resistance mediated by seven different RPP (recognition of Peronospora parasitica) genes. These data indicate that the PBS2 protein functions in a pathway that is important only to a subset of disease-resistance genes. The pbs3 mutation partially suppressed all four P. syringae-resistance genes (RPS5, RPM1, RPS2, and RPS4), and it had weak-to-intermediate effects on the RPP genes. In addition, the pbs3 mutant allowed higher bacterial growth in response to a virulent strain of P. syringae, indicating that the PBS3 gene product functions in a pathway involved in restricting the spread of both virulent and avirulent pathogens. The pbs mutations are recessive and have been mapped to chromosomes I (pbs2) and V (pbs1 and pbs3).


2008 ◽  
Vol 34 (3) ◽  
pp. 228-231 ◽  
Author(s):  
Willian Mário de Carvalho Nunes ◽  
Maria Júlia Corazza ◽  
Silvana Aparecida Crestes Dias de Souza ◽  
Siu Mui Tsai ◽  
Eiko Eurya Kuramae

A simple, quick and easy protocol was standardized for extraction of total DNA of the bacteria Xanthomonas axonopodis pv. phaseoli. The DNA obtained by this method had high quality and the quantity was enough for the Random Amplified Polymorphic DNA (RAPD) reactions with random primers, and Polymerase Chain Reaction (PCR) with primers of the hypersensitivity and pathogenicity gene (hrp). The DNA obtained was free of contamination by proteins or carbohydrates. The ratio 260nm/380nm of the DNA extracted ranged from 1.7 to 1.8. The hrp gene cluster is required by bacterial plant pathogen to produce symptoms on susceptible hosts and hypersensitive reaction on resistant hosts. This gene has been found in different bacteria as well as in Xanthomonas campestris pv. vesicatoria (9). The primers RST21 and RST22 (9) were used to amplify the hrp gene of nine different isolates of Xanthomonas axonopodis pv. phaseoli from Botucatu, São Paulo State, Brazil, and one isolate, "Davis". PCR amplified products were obtained in all isolates pathogenic to beans.


2002 ◽  
Vol 68 (9) ◽  
pp. 4604-4612 ◽  
Author(s):  
Catherine A. Axtell ◽  
Gwyn A. Beattie

ABSTRACT We constructed and characterized a transcriptional fusion that measures the availability of water to a bacterial cell. This fusion between the proU promoter from Escherichia coli and the reporter gene gfp was introduced into strains of E. coli, Pantoea agglomerans, and Pseudomonas syringae. The proU-gfp fusion in these bacterial biosensor strains responded in a quantitative manner to water deprivation caused by the presence of NaCl, Na2SO4, KCl, or polyethylene glycol (molecular weight, 8000). The fusion was induced to a detectable level by NaCl concentrations of as low as 10 mM in all three bacterial species. Water deprivation induced proU-gfp expression in both planktonic and surface-associated cells; however, it induced a higher level of expression in the surface-associated cells. Following the introduction of P. agglomerans biosensor cells onto bean leaves, the cells detected a significant decrease in water availability within only 5 min. After 30 min, the populations were exposed, on average, to a water potential equivalent to that imposed by approximately 55 mM NaCl. These results demonstrate the effectiveness of a proU-gfp-based biosensor for evaluating water availability on leaves. Furthermore, the inducibility of proU-gfp in multiple bacterial species illustrates the potential for tailoring proU-gfp-based biosensors to specific habitats.


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