Common Genes and Genomic Breaks: A Detailed Case Study of the Xylella fastidiosa Genome Backbone and Evolutionary Insights
Alessandro M. Varani, Wanessa C. Lima, Leandro M. Moreira, Mariana C. de Oliveira, Rangel de Souza, Edwin Civerolo, Ana Tereza R. de Vasconcelos and Marie-Anne Van Sluys
from: Plant Pathogenic Bacteria: Genomics and Molecular Biology (Edited by: Robert W. Jackson). Caister Academic Press, U.K. (2009)
It has been more than seven years since the first genome sequence of a plant pathogen, Xylella fastidiosa strain 9a5c, was published. At present, more than 10 genomes of the γ-Proteobacteria Xanthomonadales group are available for comparative genomics, and several studies related to functional genomics have been conducted, resulting in insights about the evolution, virulence and pathogenicity of this group of plant pathogens. The subject of this review is to explore the history of the chromosome backbone evolution and differentiation among four X. fastidiosa strains, and address the question of how and when those organisms became pathogenically competent. To address this question, three main lines of discussion are developed: (a) correlation of the bacterial life style with their genes involved in virulence and pathogenicity; (b) definition of the minimal core genome using a comparative approach; and (c) looking at the disruptions and rearrangements caused by mobile genetic elements. The discussion raised here allowed us to assess the differential evolutionary profiles inside the Xanthomonadales read more ...