Microbiology and Cell Science Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America.
Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, Illinois, United States of America.
PLoS One. 2014 Jan 8;9(1):e84469. doi: 10.1371/journal.pone.0084469. eCollection 2014.
The full genomes of two uncultured plant pathogenic Liberibacter, Ca. Liberibacter asiaticus and Ca. Liberibacter solanacearum, are publicly available. Recently, the larger genome of a closely related cultured strain, Liberibacter crescens BT-1, was described. To gain insights into our current inability to culture most Liberibacter, a comparative genomics analysis was done based on the RAST, KEGG, and manual annotations of these three organisms. In addition, pathogenicity genes were examined in all three bacteria. Key deficiencies were identified in Ca. L. asiaticus and Ca. L. solanacearum that might suggest why these organisms have not yet been cultured. Over 100 genes involved in amino acid and vitamin synthesis were annotated exclusively in L. crescens BT-1. However, none of these deficiencies are limiting in the rich media used to date. Other genes exclusive to L. crescens BT-1 include those involved in cell division, the stringent response regulatory pathway, and multiple two component regulatory systems. These results indicate that L. crescens is capable of growth under a much wider range of conditions than the uncultured Liberibacter strains. No outstanding differences were noted in pathogenicity-associated systems, suggesting that L. crescens BT-1 may be a plant pathogen on an as yet unidentified host.
两种未培养的植物病原利克氏菌，亚洲韧皮杆菌和茄科雷尔氏菌的全基因组已公开。最近，相关的已培养菌株韧皮杆菌 BT-1 的较大基因组也被描述。为了深入了解我们目前无法培养大多数利克氏菌的原因，我们基于 RAST、KEGG 和这三种生物的手动注释对其进行了比较基因组分析。此外，还对三种细菌中的致病性基因进行了检查。亚洲韧皮杆菌和茄科雷尔氏菌存在明显的缺陷，这可能表明为什么这些生物尚未被培养。100 多个参与氨基酸和维生素合成的基因仅在韧皮杆菌 BT-1 中被注释。然而，迄今为止，这些缺陷在使用的丰富培养基中都不是有限的。韧皮杆菌 BT-1 独有的其他基因包括那些参与细胞分裂、严格反应调节途径和多个双组分调节系统的基因。这些结果表明，与未培养的利克氏菌菌株相比，韧皮杆菌能够在更广泛的条件下生长。与致病性相关的系统没有明显差异，这表明韧皮杆菌 BT-1 可能是一种尚未确定宿主的植物病原体。
