Effector Gene Suites in Some Soil Isolates of Fusarium oxysporum Are Not Sufficient Predictors of Vascular Wilt in Tomato
Effector Gene Suites in Some Soil Isolates of Fusarium oxysporum Are Not Sufficient Predictors of Vascular Wilt in Tomato
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DOI：
10.1094/phyto-12-16-0437-r
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发表时间：
2017-07-01
期刊：
影响因子：
3.2
通讯作者：
Kistler, H. Corby
中科院分区：
文献类型：
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作者：
Jelinski, Nicolas A.;Broz, Karen;Kistler, H. Corby
对74个尖孢镰刀菌土壤分离株进行了已知效应基因的检测。oxysporum F.从佛罗里达的Manatee县的相同田地获得的番茄枯萎病菌株（FOL MN-25）。基于这些基因的存在或不存在，四个单倍型被定义，其中两个代表96%的调查菌株。这两种最常见的效应单倍型含有全部或不含测定的3号生理小种效应基因。我们假设，土壤菌株与所有调查的效应基因，类似于FOL MN-25，将对番茄致病，而缺乏所有效应菌株将是非致病性的。然而，接种实验表明，存在的效应基因单独是不足以确保对番茄的致病性。有趣的是，含有全套未突变效应基因（FOS 4-4）的非致病性分离株似乎经历了染色体重排，但仍与FOL MN-25保持植物相容性。这些观测结果证实了F.尖孢镰刀菌基因组的研究，并支持这一结论，致病性之间的自由生活的群体F。尖孢菌是一个复杂的过程。因此，单独的效应基因的存在可能不是一个准确的预测致病性之间的土壤分离物的F。尖孢菌属
Seventy-four Fusarium oxysporum soil isolates were assayed for known effector genes present in an F. oxysporum f. sp. lycopersici race 3 tomato wilt strain (FOL MN-25) obtained from the same fields in Manatee County, Florida. Based on the presence or absence of these genes, four haplotypes were defined, two of which represented 96% of the surveyed isolates. These two most common effector haplotypes contained either all or none of the assayed race 3 effector genes. We hypothesized that soil isolates with all surveyed effector genes, similar to FOL MN-25, would be pathogenic toward tomato, whereas isolates lacking all effectors would be nonpathogenic. However, inoculation experiments revealed that presence of the effector genes alone was not sufficient to ensure pathogenicity on tomato. Interestingly, a nonpathogenic isolate containing the full suite of unmutated effector genes (FOS 4-4) appears to have undergone a chromosomal rearrangement yet remains vegetatively compatible with FOL MN-25. These observations confirm the highly dynamic nature of the F. oxysporum genome and support the conclusion that pathogenesis among free-living populations of F. oxysporum is a complex process. Therefore, the presence of effector genes alone may not be an accurate predictor of pathogenicity among soil isolates of F. oxysporum.