ARS | Publication request: Complete genome sequence analyses and functional implications of ‘Candidatus Liberibacter solanacearum’, the bacterium associated with potato zebra chip diseases

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 20, 2011
Publication Date: June 1, 2011
Citation: Lin, H., Glynn, J., Civerolo, E.L. 2011. Complete genome sequence analyses and functional implications of ‘Candidatus Liberibacter solanacearum’, the bacterium associated with potato zebra chip diseases. American Phytopathological Society Abstracts. 101:S105.

Technical Abstract: Zebra Chip (ZC) is an emerging plant disease that causes the decline of potato shoots and generally results in unusable tubers. ZC is characterized by discoloration or striped pattern of necrosis of tubers. Fried chips from ZC-diseased tubers are commercially unacceptable. The disease has significantly impacted the U.S. potato industry as well as potato growing regions worldwide. ZC is associated with ‘Candidatus Liberibacter solanacearum (Lso)’, a fastidious alpha-proteobacterium that is transmitted by a phloem-feeding psyllid vector, Bactericera cockerelli Sulc. Taxonomically, Lso is related to ‘Candidatus Liberibacter asiaticus’ (Las), a putative causal agent of citrus huanglongbing. Research on ZC disease has been hampered by the fact that the bacterium is unculturable, such that pure target genomic DNA is unavailable. In spite of these limitations, high quality Lso genomic DNA was obtained using an immune-capture technique. The complete 1.26 Mbp metagenome sequences of Lso were based on Lso DNA isolated from potato psyllids. The coding inventory of the ‘Candidatus Liberibacter solanacearum’ genome was analyzed and compared to related bacteria of Rhizobiaceae to identify genes and predict possible physiological functions. The analyses revealed a number of unique transporters and metabolic pathways, all potentially contributing to ZC pathogenesis. Similar to Las, Lso has a reduced genome which likely reflects its fastidious nature. Information derived from this study will facilitate development of effective strategies for controlling ZC disease.