Remarkable recent changes in the genetic diversity of the avirulence gene AvrStb6 in global populations of the wheat pathogen Zymoseptoria tritici.
Remarkable recent changes in the genetic diversity of the avirulence gene AvrStb6 in global populations of the wheat pathogen Zymoseptoria tritici.
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小麦病原菌Zymoseptoria triumphoria全球种群无毒基因AvrStb6遗传多样性的近期显著变化。
DOI：
10.1111/mpp.13101
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发表时间：
2021-09
影响因子：
4.9
通讯作者：
Kanyuka K
中科院分区：
文献类型：
--
作者：
Stephens C;Ölmez F;Blyth H;McDonald M;Bansal A;Turgay EB;Hahn F;Saintenac C;Nekrasov V;Solomon P;Milgate A;Fraaije B;Rudd J;Kanyuka K
小麦壳针孢斑点病（STB）是由三孢发酵壳针孢菌（Zymoseptoria triacetylum）引起的小麦重要病害之一。最近，已经鉴定了小麦受体样激酶Stb6和小麦间的基因对基因相互作用的两个因子，即小麦受体样激酶Stb6和玉米分泌的效应蛋白AvrStb6。先前的分析显示，早期的玉米单胞菌分离物集合中存在高度多样性的AvrStb6单倍型，高达约18%的分析分离物具有与参考分离物IPO323中最初鉴定的AvrStb6相同的无毒力同种型。由于Stb6存在于全球许多商业小麦品种中，我们的目的是评估AvrStb6遗传多样性的潜在变化和最近的玉米群体中允许逃避Stb6介导的抗性的单倍型的发生率。在这里，我们使用AvrStb6的靶向重测序表明，该基因普遍存在于2013 - 2017年从世界主要小麦种植区采样的田间分离株中。然而，与先前AvrStb6群体研究的数据相反，我们报告了在现代三孢木单胞菌分离株中完全不存在最初描述的AvrStb6无毒力同种型。此外，发现非常少量的单倍型（每个编码AvrStb6蛋白同种型调节对含Stb6小麦的毒力）在现代玉米单胞菌分离株中占主导地位。发现AvrStb6的单一毒力同种型在全球人群中特别丰富。这些发现表明，尽管Z.trillium在抗性宿主上有性繁殖的能力，AvrStb6无毒单倍型倾向于在随后的群体中被消除。AvrStb6亚型多样性的快照之间的早期与最近的自然Zymoseptoria triumphium种群显示了显着的多样性下降和全球性的转移到Stb6小麦的毒力。
Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici, is one of the most economically important diseases of wheat. Recently, both factors of a gene‐for‐gene interaction between Z. tritici and wheat, the wheat receptor‐like kinase Stb6 and the Z. tritici secreted effector protein AvrStb6, have been identified. Previous analyses revealed a high diversity of AvrStb6 haplotypes present in earlier Z. tritici isolate collections, with up to c.18% of analysed isolates possessing the avirulence isoform of AvrStb6 identical to that originally identified in the reference isolate IPO323. With Stb6 present in many commercial wheat cultivars globally, we aimed to assess potential changes in AvrStb6 genetic diversity and the incidence of haplotypes allowing evasion of Stb6‐mediated resistance in more recent Z. tritici populations. Here we show, using targeted resequencing of AvrStb6, that this gene is universally present in field isolates sampled from major wheat‐growing regions of the world in 2013–2017. However, in contrast to the data from previous AvrStb6 population studies, we report a complete absence of the originally described avirulence isoform of AvrStb6 amongst modern Z. tritici isolates. Moreover, a remarkably small number of haplotypes, each encoding AvrStb6 protein isoforms conditioning virulence on Stb6‐containing wheat, were found to predominate among modern Z. tritici isolates. A single virulence isoform of AvrStb6 was found to be particularly abundant throughout the global population. These findings indicate that, despite the ability of Z. tritici to sexually reproduce on resistant hosts, AvrStb6 avirulence haplotypes tend to be eliminated in subsequent populations. A snapshot of AvrStb6 isoforms diversity amongst earlier versus more recent natural Zymoseptoria tritici populations revealed a marked decrease in diversity and a global shift to virulence on Stb6 wheat.
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影响因子：
4.9
作者：
Clement, M;Posada, D;Crandall, KA
通讯作者：
Crandall, KA
DOI：
10.3390/plants7020027
发表时间：
2018-03-28
期刊：
Plants (Basel, Switzerland)
影响因子：
--
作者：
Alotaibi SS;Sparks CA;Parry MAJ;Simkin AJ;Raines CA
通讯作者：
Raines CA
影响因子：
4
作者：
Dong, Suomeng;Raffaele, Sylvain;Kamoun, Sophien
通讯作者：
Kamoun, Sophien
影响因子：
10.7
作者：
Katoh K;Standley DM
通讯作者：
Standley DM
影响因子：
6.6
作者：
Leigh, Jessica W.;Bryant, David
通讯作者：
Bryant, David