EPIDEMIOLOGY AND MANAGEMENT OF XYLELLA FASTIDIOSA (XF) AND OTHER EXOTIC AND INVASIVE DISEASES AND INSECT PESTS
Location: Crop Diseases, Pests and Genetics
Title: Comparative Analyses Of The ‘Candidatus Liberibacter’ Species Reductive Genome Features
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 10, 2010
Publication Date: June 1, 2010
Citation: Doddapaneni, H., Lin, H., Duan, Y., Lou, B., Chen, C., Vahling, C.M., Lijuan, Z., Civerolo, E.L. 2010. Comparative Analyses Of The ‘Candidatus Liberibacter’ Species Reductive Genome Features. Phytopathology. 100:S30.
‘Candidatus Liberibacter’ species are gram-negative a-proteobacteria that are associated with some destructive plant diseases such as citrus Huanglongbing and potato ‘zebra chip’. These bacteria are transmitted by psyllids and are classified into four species. Using whole genome amplification and 454 pyrosequencing, we have sequenced the genomes of ‘Ca. Liberibacter asiaticus’ (Las) and ‘Ca. Liberibacter solanacearum’ (Lso). A total of 1,136 and 1,126 CDS were predicted in Las and Lso, respectively. Comparative genomics and metabolic pathway analyses have revealed some details, such as the presence of reductive oxidative phosphorylation, the reduction or complete absence of metabolic enzymes and secretion systems in these genomes. There are 867 conserved proteins, of which, 531 proteins shared =70% similarity and may represent the core genome of the ‘Ca. Liberibacter’ species. The remaining 336 proteins showed greater diversification and a significant portion of those are associated with membrane and transport functions, and that may help define their speciation. Similarly, Lso and Las genomes differ by > 25% quantitatively among six functional COG categories. Five of these categories are related to external interactions that are associated with a pathogenic lifestyle. The reduced metabolic capabilities, which reflect their fastidious nature, along with the presence of pseudogenes suggest ongoing genome decay in this group of bacteria.