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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Homologous Recombination and Xylella fastidiosa Host-Pathogen Associations in South America

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Coletta-Filho, Helvecio D. ; Francisco, Carolina S. ; Lopes, Joao R. S. ; Muller, Christian ; Almeida, Rodrigo P. P.
Total Authors: 5
Document type: Journal article
Source: PHYTOPATHOLOGY; v. 107, n. 3, p. 305-312, MAR 2017.
Web of Science Citations: 18

Homologous recombination affects the evolution of bacteria such as Xylella fastidiosa, a naturally competent plant pathogen that requires insect vectors for dispersal. This bacterial species is taxonomically divided into subspecies, with phylogenetic clusters within subspecies that are host specific. One subspecies, pauca, is primarily limited to South America, with the exception of recently reported strains in Europe and Costa Rica. Despite the economic importance of X. fastidiosa subsp. pauca in South America, little is known about its genetic diversity. Multilocus sequence typing (MLST) has previously identified six sequence types (ST) among plant samples collected in Brazil (both subsp. pauca and multiplex). Here, we report on a survey of X. fastidiosa genetic diversity (MLST based) performed in six regions in Brazil and two in Argentina, by sampling five different plant species. In addition to the six previously reported ST, seven new subsp. pauca and two new subsp. multiplex ST were identified. The presence of subsp. multiplex in South America is considered to be the consequence of a single introduction from its native range in North America more than 80 years ago. Different phylogenetic approaches clustered the South American ST into four groups, with strains infecting citrus (subsp. pauca); coffee and olive (subsp. pauca); coffee, hibiscus, and plum (subsp. pauca); and plum (subsp. multiplex). In areas where these different genetic clusters occurred sympatrically, we found evidence of homologous recombination in the form of bidirectional allelic exchange between subspp. pauca and multiplex. In fact, the only strain of subsp. pauca isolated from a plum host had an allele that originated from subsp. multiplex. These signatures of bidirectional homologous recombination between endemic and introduced ST indicate that gene flow occurs in short evolutionary time frames in X. fastidiosa, despite the ecological isolation (i.e., host plant species) of genotypes. (AU)

FAPESP's process: 11/13803-9 - Population structure and reciprocal inoculation of Xylella fastidiosa subsp. pauca occurring in neighbor orchards of citrus sinensis and Coffea arabica growing in the São Paulo State
Grantee:Helvecio Della Coletta Filho
Support type: Regular Research Grants
FAPESP's process: 11/14479-0 - Structure of populations and reciprocal inoculations of Xylella fastidiosa subsp. pauca occurring in neighboring cultures of citrus sinensis and Coffea arabica in conditions of São Paulo
Grantee:Carolina Sardinha Francisco
Support type: Scholarships in Brazil - Master