University of Exeter, Exeter, UK.
FEMS Microbiol Lett. 2010 Sep 1;310(2):182-92. doi: 10.1111/j.1574-6968.2010.02065.x. Epub 2010 Jul 15.
Banana Xanthomonas wilt is a newly emerging disease that is currently threatening the livelihoods of millions of farmers in East Africa. The causative agent is Xanthomonas campestris pathovar musacearum (Xcm), but previous work suggests that this pathogen is much more closely related to species Xanthomonas vasicola than to X. campestris. We have generated draft genome sequences for a banana-pathogenic strain of Xcm isolated in Uganda and for a very closely related strain of X. vasicola pathovar vasculorum, originally isolated from sugarcane, that is nonpathogenic on banana. The draft sequences revealed overlapping but distinct repertoires of candidate virulence effectors in the two strains. Both strains encode homologues of the Pseudomonas syringae effectors HopW, HopAF1 and RipT from Ralstonia solanacearum. The banana-pathogenic and non-banana-pathogenic strains also differed with respect to lipopolysaccharide synthesis and type-IV pili, and in at least several thousand single-nucleotide polymorphisms in the core conserved genome. We found evidence of horizontal transfer between X. vasicola and very distantly related bacteria, including members of other divisions of the Proteobacteria. The availability of these draft genomes will be an invaluable tool for further studies aimed at understanding and combating this important disease.
香蕉束顶病毒病是一种新出现的疾病，目前正威胁着东非数百万农民的生计。病原体是香蕉束顶病毒（Xcm），但先前的研究表明，这种病原体与黄单胞菌（Xanthomonas vasicola）的亲缘关系比与野油菜黄单胞菌（X. campestris）更为密切。我们为在乌干达分离出的香蕉致病型 Xcm 菌株和与该菌株密切相关的、原本从甘蔗中分离出的非致病型香蕉黄单胞菌（X. vasicola）叶脉型菌株生成了基因组草图。这两个菌株的候选致病效应子重叠但又有区别。两个菌株都编码了雷尔氏菌（Ralstonia solanacearum）中假单胞菌（Pseudomonas syringae）效应物 HopW、HopAF1 和 RipT 的同源物。在脂多糖合成和 IV 型菌毛方面，以及在核心保守基因组中至少数千个单核苷酸多态性方面，香蕉致病型和非香蕉致病型菌株也有所不同。我们发现了黄单胞菌与非常远缘的细菌之间存在水平转移的证据，包括其他细菌门的成员。这些基因组草图的提供将是进一步研究理解和防治这种重要疾病的宝贵工具。
