|SHIM, WAN BO|
Submitted to: Journal of Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 6/30/2008
Publication Date: 12/1/2008
Citation: Ma, L., Shim, W., Woloshuk, C., Kang, S., Kistler, H.C. 2008. Fusarium Comparative Genomics Reveals Genome Dynamics and Its Impacts on Pathogenesis [abstract]. Journal of Phytopathology. 90:S3.11.
Technical Abstract: Collectively, Fusaria are the most important plant pathogens, causing disease in nearly every agriculturally important plant. To employ the power of comparative genomics in understanding pathogenesis, three closely related species, F. graminearum, F. verticillioides and F. oxysporum, have been sequenced and analyzed. The sequence relatedness among these carefully selected genomes allows an unprecedented ability to determine orthologs, and to identify species-specific features. Over 90% of the F. verticillioides genome can be unambiguously aligned to the syntenic regions in F. oxysporum with an average 90% sequence identity. Specifically, all the eleven chromosomes in F. verticillioides have corresponding chromosomes in F. oxysporum and F. graminearum. In contrast, four of the F. oxysporum chromosomes, accounting for over 15 Mb, lack significant orthologous sequence in the other two genomes. These F. oxysporum-specific chromosomes are enriched for genes that encode secreted proteins including the known virulence factors such as, SIX (Secreted in Xylem) proteins and plant cell wall degrading enzymes. Various transposable elements also are over-represented in these chromosomes. Chromosome polymorphism among strains of the species complex is reflected in electrophoretic karyotype variation and confirmed by preliminary sequence analysis of a second strain of F. oxysporum. The prevalence of the chromosomal polymorphism within the species complex, which has wide host range, may indicate the association of these species-specific chromosomes and adaptation of the organism to diverse ecological niches. Examining sequence content and evolutionary mechanisms underlying the acquisition and diversification of such genetic material will open the door to understanding the development of pathogenesis and host specificity.