Comparative and functional genomic analyses of the pathogenicity of phytopathogen Xanthomonas campestris pv. campestris
Comparative and functional genomic analyses of the pathogenicity of phytopathogen Xanthomonas campestris pv. campestris
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DOI：
10.1101/gr.3378705
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发表时间：
2005-06-01
期刊：
影响因子：
7
通讯作者：
He, CZ
中科院分区：
文献类型：
--
作者：
Qian, W;Jia, YT;He, CZ
野油菜黄单胞菌致病变种（Xanthomonascampestrispathovarcampestris，Xcc）是十字花科蔬菜黑腐病的病原菌，在世界范围内造成严重的农业损失。这种细菌是研究植物-细菌相互作用的模式生物。我们测序了Xcc 8004的全基因组（5，148，708 bp），其相对于Xcc ATCC 33913高度保守。比较基因组学分析表明，除了两个IS 1478元件之间的复制轴上的显著基因组规模重排外，基因块的丢失和获得，而不是点突变，构成了两个Xcc菌株之间的主要遗传变异。对Xcc 8004的高密度转座子插入突变体文库（16，512个克隆）针对宿主植物（甘蓝）的筛选鉴定出75个在蛋白质编码序列（CDS）和基因间区域中的非冗余、单拷贝插入。除了已知的毒力因子外，发现完全毒力需要几个额外的代谢途径和调节系统，如脂肪酸降解、IV型分泌系统、细胞信号传导以及氨基酸和核苷酸代谢。在已鉴定的致病性相关基因中，在Xcc 8004特异性染色体片段中发现了3个功能未知的基因，揭示了基因组动态与Xcc毒力之间的直接相关性。目前的比较和功能基因组分析相结合，提供了有价值的信息Xcc致病性的遗传基础，这可能提供新的见解，朝着发展有效的方法来预防这一重要的植物疾病。
Xanthomonas campestris pathovar campestris (Xcc) is the causative agent of crucifer black rot disease, which causes severe losses in agricultural yield world-wide. This bacterium is a model organism for studying plant-bacteria interactions. We sequenced the complete genome of Xcc 8004 (5,148,708 bp), which is highly conserved relative to that of Xcc ATCC 33913. Comparative genomics analysis indicated that, in addition to a significant genomic-scale rearrangement cross the replication axis between two IS1478 elements, loss and acquisition of blocks of genes, rather than point mutations, constitute the main genetic variation between the two Xcc strains. Screening of a high-density transposon insertional mutant library (16,512 clones) of Xcc 8004 against a host plant (Brassica oleraceae) identified 75 nonredundant, single-copy insertions in protein-coding sequences (CDSs) and intergenic regions. In addition to known virulence factors, full virulence was found to require several additional metabolic pathways and regulatory systems, such as fatty acid degradation, type IV secretion system, cell signaling, and amino acids and nucleotide metabolism. Among the identified pathogenicity-related genes, three of unknown function were found in Xcc 8004-specific chromosomal segments, revealing a direct correlation between genomic dynamics and Xcc virulence. The present combination of comparative and functional genomic analyses provides valuable information about the genetic basis of Xcc pathogenicity, which may offer novel insight toward the development of efficient methods for prevention of this important plant disease.