Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/30/2015
Publication Date: 9/16/2016
Citation: Mc Cue, K.F., Lazo, G.R., Munyaneza, J.E. 2016. Sequence analysis of Candidatus Liberibacter solanacearum (Lso-C) isolated from carrot psyllids collected in Scandinavia. Meeting Proceedings. 2014. pp 152-156.
Interpretive Summary: The zebra chip disease of potato is caused by infection with the bacterium ‘Candidatus’ Liberibacter solanacearum. This bacterium is transmitted to the potato by the phloem-feeding tomato potato psyllid. This insect can spread the same bacterium to other solanaceous plants such as the tomato, pepper and eggplant where it also produces disease symptoms. A different psyllid insect has also been shown to transmit Liberibacter solanacearum to carrots causing disease symptoms. This is related to a bacterium transmitted by psyllids to citrus causing the devastating citrus greening or huánglóngbìng (HLB) disease. We have generated genomic sequence information from the bacteria infecting carrots by extracting the DNA of the psyllids. This has provided us with information on the Liberibacter genome isolated from carrots showing both identical regions as well as those containing specific differences compared to the bacterial genome infecting potatoes. With this sequence information we are discerning the differences between the bacteria in different location in Europe and between the European and American strains. This information will help monitor the occurrence and spread of the disease as well as help to find targets to combat this disease in multiple crops.
Technical Abstract: The fastidious prokaryote Candidatus Liberibacter solanacearum (Lso), transmitted by the tomato potato psyllid (Bactericera cockerelli), is associated with the Zebra Chip disease of potato. Plants infected with Liberibacter may experience significant yield losses and these plants also serve as potential reservoirs for Liberibacter to spread to other psyllid hosts with alternate crop feeding preferences, potentially introducing new epidemiological focal points among crops. New associations between Liberibacter species and crop plants have been detected in different parts of the world, presenting concerns about the potential roles of these strains in causing disease. Carrots (Daucus carota) showing damage from feeding of carrot psyllids (Trioza apicalis) were reported to be infected with Lso. Using sequence information generated from Lso positive psyllids collected in Finland, Norway and Sweden we have constructed a metagenomics map for this new Lso haplotype LsoC. We have compared the genomes of the LsoC to the closely related LsoB haplotype, the only Lso whose genome sequence is currently available. In addition differences between the Lso sequences derived from samples from each country were identified. These differences will aid in the monitoring of the regional populations.