Evolution of the EKA family of powdery mildew avirulence-effector genes from the ORF 1 of a LINE retrotransposon.
Evolution of the EKA family of powdery mildew avirulence-effector genes from the ORF 1 of a LINE retrotransposon.
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DOI：
10.1186/s12864-015-2185-x
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发表时间：
2015-11-10
期刊：
影响因子：
4.4
通讯作者：
Sacristán S
中科院分区：
文献类型：
--
作者：
Amselem J;Vigouroux M;Oberhaensli S;Brown JK;Bindschedler LV;Skamnioti P;Wicker T;Spanu PD;Quesneville H;Sacristán S
Avrk 1和Avra 10无毒（AVR）基因编码的效应子，增加真菌小麦白粉病菌大麦（Bgh），白粉病病原体，在易感大麦植物的致病性。在抗性大麦中，MLK 1和MLA 10抗性蛋白识别AVRK 1和AVRA 10的存在，引发典型的基因对基因相互作用的过敏反应。Avrk 1和Avra 10在Bgh基因组中有1350多个同源基因，形成了EKA（Effectors homologous to Avrk 1 and Avra 10）基因家族。我们测试的假设，即EKA家族起源于I类LINE反转录转座子的简并拷贝，通过分析的EKA家族的基因组中的Bgh分离DH 14与生物信息学工具，专门开发的基因组中的转座因子（TE）的分析。与Avrk 1和Avra 10同源的I类LINE逆转录转座子拷贝占Bgh注释基因组的6.5%，其中，我们鉴定了293个AVR/效应子候选基因。我们还通过实验鉴定了表明EKA家族成员中几种预测蛋白质翻译的肽，这些蛋白质在吸器中的相对丰度高于菌丝。我们的分析表明，Avrk 1和Avra 10已经从I类LINE反转录转座子的ORF 1基因的一部分进化而来。Avra 10和Avrk 1作为来自截短的反转录转座子拷贝的效应子的共同选择解释了Bgh基因组中大量的同源物，这些同源物可以作为新的效应基因可能进化的动态水库。这些数据为逆转录转座子在新的生物学功能的进化中的募集提供了进一步的证据。本文的在线版本（doi：10.1186/s12864-015-2185-x）包含补充材料，可供授权用户使用。
The Avrk1 and Avra10 avirulence (AVR) genes encode effectors that increase the pathogenicity of the fungus Blumeria graminis f.sp. hordei (Bgh), the powdery mildew pathogen, in susceptible barley plants. In resistant barley, MLK1 and MLA10 resistance proteins recognize the presence of AVRK1 and AVRA10, eliciting the hypersensitive response typical of gene for gene interactions. Avrk1 and Avra10 have more than 1350 homologues in Bgh genome, forming the EKA (Effectors homologous to Avrk1 and Avra10) gene family. We tested the hypothesis that the EKA family originated from degenerate copies of Class I LINE retrotransposons by analysing the EKA family in the genome of Bgh isolate DH14 with bioinformatic tools specially developed for the analysis of Transposable Elements (TE) in genomes. The Class I LINE retrotransposon copies homologous to Avrk1 and Avra10 represent 6.5 % of the Bgh annotated genome and, among them, we identified 293 AVR/effector candidate genes. We also experimentally identified peptides that indicated the translation of several predicted proteins from EKA family members, which had higher relative abundance in haustoria than in hyphae. Our analyses indicate that Avrk1 and Avra10 have evolved from part of the ORF1 gene of Class I LINE retrotransposons. The co-option of Avra10 and Avrk1 as effectors from truncated copies of retrotransposons explains the huge number of homologues in Bgh genome that could act as dynamic reservoirs from which new effector genes may evolve. These data provide further evidence for recruitment of retrotransposons in the evolution of new biological functions. The online version of this article (doi:10.1186/s12864-015-2185-x) contains supplementary material, which is available to authorized users.