Genomic Insights into the Evolutionary Origin of Xanthomonas axonopodis pv. citri and Its Ecological Relatives
Genomic Insights into the Evolutionary Origin of Xanthomonas axonopodis pv. citri and Its Ecological Relatives
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DOI：
10.1128/aem.01654-14
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发表时间：
2014-10-01
影响因子：
4.4
通讯作者：
Patil, Prabhu B.
中科院分区：
文献类型：
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作者：
Midha, Samriti;Patil, Prabhu B.
轴足黄单胞菌致病变种柑桔溃疡病（Citri，Xac）是柑桔细菌性溃疡病（Citrus Bacterial Canker，CBC）的病原，是世界性的严重病害。与CBC一样，其他水果（如芒果、石榴和葡萄）中的几种重要疾病也是由对宿主表现出显著特异性的黄单胞菌致病变种引起的。虽然柑橘和芒果疾病在100多年前就有记载，但石榴和葡萄疾病分别在20世纪50年代和70年代才被发现。有趣的是，所有这些致病型引起的疾病首先在印度发现。我们基于基因组的系统发育研究表明，这些不同的病原体属于一个单一的物种，这些致病型可能只是一组快速进化的菌株。此外，最近报道的致病变种，如那些感染葡萄和石榴，形成独立的克隆谱系，而柑橘和芒果的致病变种，已经知道了很长一段时间，形成一个克隆谱系。对它们的染色体组间关系的这种理解，进一步使我们能够理解产生这些致病型的谱系中的主要和独特的变异。全基因组测序研究，包括生态亲属从他们假定的原产国，使我们能够了解Xac和其他致病变种，感染水果的进化历史。
Xanthomonas axonopodis pv. citri (Xac) is the causal agent of citrus bacterial canker (CBC) and is a serious problem worldwide. Like CBC, several important diseases in other fruits, such as mango, pomegranate, and grape, are also caused by Xanthomonas pathovars that display remarkable specificity toward their hosts. While citrus and mango diseases were documented more than 100 years ago, the pomegranate and grape diseases have been known only since the 1950s and 1970s, respectively. Interestingly, diseases caused by all these pathovars were noted first in India. Our genome-based phylogenetic studies suggest that these diverse pathogens belong to a single species and these pathovars may be just a group of rapidly evolving strains. Furthermore, the recently reported pathovars, such as those infecting grape and pomegranate, form independent clonal lineages, while the citrus and mango pathovars that have been known for a long time form one clonal lineage. Such an understanding of their phylogenomic relationship has further allowed us to understand major and unique variations in the lineages that give rise to these pathovars. Whole-genome sequencing studies including ecological relatives from their putative country of origin has allowed us to understand the evolutionary history of Xac and other pathovars that infect fruits.