Agroscope Changins-Wädenswil ACW, Division of Plant Protection, Swiss National Competence Center for Fire Blight, CH-8820 Wädenswil, Switzerland.
J Biotechnol. 2011 Aug 20;155(1):34-9. doi: 10.1016/j.jbiotec.2010.10.075. Epub 2010 Oct 30.
Evolutionary genomics is coming into focus with the recent availability of complete sequences for many bacterial species. A hypothesis on the evolution of virulence factors in the plant pathogen Erwinia amylovora, the causative agent of fire blight, was generated using comparative genomics with the genomes E. amylovora, Erwinia pyrifoliae and Erwinia tasmaniensis. Putative virulence factors were mapped to the proposed genealogy of the genus Erwinia that is based on phylogenetic and genomic data. Ancestral origin of several virulence factors was identified, including levan biosynthesis, sorbitol metabolism, three T3SS and two T6SS. Other factors appeared to have been acquired after divergence of pathogenic species, including a second flagellar gene and two glycosyltransferases involved in amylovoran biosynthesis. E. amylovora singletons include 3 unique T3SS effectors that may explain differential virulence/host ranges. E. amylovora also has a unique T1SS export system, and a unique third T6SS gene cluster. Genetic analysis revealed signatures of foreign DNA suggesting that horizontal gene transfer is responsible for some of these differential features between the three species.
随着许多细菌物种的完整序列的最近可用，进化基因组学成为焦点。使用比较基因组学方法，对植物病原体梨火疫病菌（Erwinia amylovora）的毒力因子进化进行了假设，该病原体是火疫病的病原体。假定的毒力因子被映射到基于系统发育和基因组数据的拟议的欧文氏菌属的系统发生树上。鉴定了几个毒力因子的祖先起源，包括蔗聚糖生物合成、山梨糖醇代谢、三个 T3SS 和两个 T6SS。其他因子似乎是在致病物种分化后获得的，包括第二个鞭毛基因和参与多糖生物合成的两个糖基转移酶。梨火疫病菌的单核苷酸多态性包括 3 个独特的 T3SS 效应子，这可能解释了不同的毒力/宿主范围。梨火疫病菌还具有独特的 T1SS 输出系统和独特的第三个 T6SS 基因簇。遗传分析显示了外源 DNA 的特征，表明水平基因转移是这些三个物种之间的一些差异特征的原因。
