Comparative genomics of the liberibacteral plant pathogens

Abstract

The pathogenic 'Candidatus Liberibacter' species have caused tremendous economic losses to agricultural crops. Since these bacteria are, generally, not yet unculturable, information regarding genetics and pathogenesis of the pathogens is limited. Comparative analyses of multiple Liberibacter genomes provide unprecedented insights into the evolutionary history, phylogenetic diversity, and metabolomic capacities among pathogenic bacteria. In addition, genomic analyses of plant disease-associated Liberibacters have led to the identification of potential or putative pathogenicity and virulence factors, as well as biomarkers associated with Liberibacter-host plant interactions. The availability of specific biomarkers associated with Liberibacter-host plant interactions will aid in the development of improved, reliable diagnostic protocols for early (i.e., presymptomatic), rapid Liberibacter detection as part of disease management strategies. Since no host resistance has been found in Liberibacter-associated diseases, knowledge of specific Liberibacter genes and their products associated with pathogenicity and virulence, as well as interactions with psyllid vectors, will lead to the identification of potential targets for mitigating Liberibacter acquisition and transmission by psyllids, host plant infection, and disease development. Finally, genomics-based research will facilitate improved understanding of the complex and diverse mechanisms of Liberibacter-plant interactions.