Investigation of the diversity of effector genes in the banana pathogen, Fusarium oxysporum f. sp cubense, reveals evidence of horizontal gene transfer
Investigation of the diversity of effector genes in the banana pathogen, Fusarium oxysporum f. sp cubense, reveals evidence of horizontal gene transfer
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DOI：
10.1111/mpp.12594
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发表时间：
2018-05-01
影响因子：
4.9
通讯作者：
Aitken, Elizabeth A. B.
中科院分区：
文献类型：
--
作者：
Czislowski, Elizabeth;Fraser-Smith, Sam;Aitken, Elizabeth A. B.
据推测，植物病原真菌的毒力是通过分泌干扰宿主植物防御反应的小效应蛋白介导的。在尖孢镰刀菌中，已经鉴定了一个效应子家族，木质部分泌（SIX）基因。我们试图描述香蕉感染F. oxysporum F. sp. cubense（Foc.）为Foc的23个遗传谱系生成全基因组测序数据，随后查询14个已知的SIX基因（SIX 1-SIX 14）。鉴定的SIX基因的序列在更大的Foc分离株集合中得到证实。为Foc中鉴定的每个SIX基因生成系谱，以进一步研究Foc中SIX基因的进化。在Foc内，SIX基因谱的变化，包括特定SIX同源物的存在，与致病性种族结构的Foc相关。此外，SIX基因树的拓扑结构与从EF-1 α/RPB 1/RPB 2（翻译延伸因子-1 α/RNA聚合酶II亚基I/RNA聚合酶II亚基II）推断的种下遗传学拓扑结构不一致。一系列的拓扑约束模型为Foc中SIX基因的水平传递提供了有力的证据。Foc中致病基因的水平遗传反驳了以前的假设，即趋同进化驱动了Foc的多系同源性。这项工作对Foc的管理具有重要意义，包括改进诊断和育种方案。
It is hypothesized that the virulence of phytopathogenic fungi is mediated through the secretion of small effector proteins that interfere with the defence responses of the host plant. In Fusarium oxysporum, one family of effectors, the Secreted In Xylem (SIX) genes, has been identified. We sought to characterize the diversity and evolution of the SIX genes in the banana-infecting lineages of F. oxysporum f. sp. cubense (Foc). Whole-genome sequencing data were generated for the 23 genetic lineages of Foc, which were subsequently queried for the 14 known SIX genes (SIX1-SIX14). The sequences of the identified SIX genes were confirmed in a larger collection of Foc isolates. Genealogies were generated for each of the SIX genes identified in Foc to further investigate the evolution of the SIX genes in Foc. Within Foc, variation of the SIX gene profile, including the presence of specific SIX homologues, correlated with the pathogenic race structure of Foc. Furthermore, the topologies of the SIX gene trees were discordant with the topology of an infraspecies phylogeny inferred from EF-1 alpha/RPB1/RPB2 (translation elongation factor-1 alpha/RNA polymerase II subunit I/RNA polymerase II subunit II). A series of topological constraint models provided strong evidence for the horizontal transmission of SIX genes in Foc. The horizontal inheritance of pathogenicity genes in Foc counters previous assumptions that convergent evolution has driven the polyphyletic phylogeny of Foc. This work has significant implications for the management of Foc, including the improvement of diagnostics and breeding programmes.