SciELO - Scientific Electronic Library Online

vol.29 issue1Identification and taxonomy of some entomopathogenic Paecilomyces spp. (Ascomycota) isolates using rDNA-ITS SequencesIndividual sensitivity to cytogenetic effects of benzo[alpha]pyrene in cultured human lymphocytes: influence of glutathione S-transferase M1 genotype author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Genetics and Molecular Biology

Print version ISSN 1415-4757On-line version ISSN 1678-4685


PACHECO, Flávia Teresa Hansen et al. Specific amplification of iron receptor genes in Xylella fastidiosa strains from different hosts. Genet. Mol. Biol. [online]. 2006, vol.29, n.1, pp.137-141. ISSN 1415-4757.

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, ragweed, periwinkle and grape also infected by X. fastidiosa were also shown by the chromeazurol bioassay to produce siderophores. In order to correlate siderophore production with the presence of siderophore-related genes, a polymerase chain reaction (PCR) was developed using specific primers for the catechol-type ferric enterobactin receptor (pfeA) and the hydroxamate-type ferrisiderophore receptor (fiuA) genes of strain 9a5c. The PCR results confirmed our hypothesis by demonstrating that amplification products were detected in all strains except for those isolates that did not produce siderophores.

Keywords : citrus variegated chlorosis; plant pathogen; iron-transportation; pyoverdine; enterobactin; polyketide synthase; peptide synthetase.

        · text in English     · English ( pdf epdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License