The evolution of the Gp-Rbp-1 gene in Globodera pallida includes multiple selective replacements
The evolution of the Gp-Rbp-1 gene in Globodera pallida includes multiple selective replacements
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DOI：
10.1111/j.1364-3703.2011.00769.x
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发表时间：
2012-08-01
影响因子：
4.9
通讯作者：
Grenier, Eric
中科院分区：
文献类型：
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作者：
Carpentier, Jean;Esquibet, Magali;Grenier, Eric
Globodera pallida SPRYSEC Gp-Rbp-1基因编码一种分泌蛋白，其诱导由马铃薯抗病基因Gpa 2介导的效应子触发免疫（ETI）。尽管如此，尚不清楚安第斯山脉、沿着科迪勒拉山脉发现的茄属物种的丰富性或线虫引入欧洲如何影响Gp-Rbp-1的多样性及其被Gpa 2识别。我们生成了一个数据集的157个高度多态性的Gp-Rbp-1序列，并确定了三个Gp-Rbp-1的进化途径：北方秘鲁，秘鲁分支I/欧洲和智利的路径。这些可能是由线虫的被动传播和影响野生宿主物种的性质和多样性的气候变化造成的。我们还证实，通过对Gp-Rbp-1的选择压力的分析，该基因在正/多样化选择下进化，但在所描述的三种进化途径中不同。使用这个扩展的序列数据集，我们能够在正选择下检测到八个位点。六个网站似乎是特别感兴趣的，因为它们的预测本地化的B30.2域的扩展循环和/或支持几种计算方法。P/S 187位置先前被鉴定为对与GPA 2的相互作用的影响。其他五个氨基酸多态性的功能的重要性进行了研究，使用农杆菌瞬时转化试验。这些新的残基，但是，似乎是直接参与Gpa 2介导的植物防御机制。因此，在位置187处观察到的P/S多态性仍然是足以解释Gpa 2识别Gp-Rbp-1的唯一变异。
The Globodera pallida SPRYSEC Gp-Rbp-1 gene encodes a secreted protein which induces effector-triggered immunity (ETI) mediated by the Solanum tuberosum disease resistance gene Gpa2. Nonetheless, it is not known how the Andes orogeny, the richness in Solanum species found along the Cordillera or the introduction of the nematode into Europe have affected the diversity of Gp-Rbp-1 and its recognition by Gpa2. We generated a dataset of 157 highly polymorphic Gp-Rbp-1 sequences and identified three Gp-Rbp-1 evolutionary pathways: the Northern Peru, Peru clade I/European and Chilean paths. These may have been shaped by passive dispersion of the nematode and by climatic variations that have influenced the nature and diversity of wild host species. We also confirmed that, by an analysis of the selection pressures acting on Gp-Rbp-1, this gene has evolved under positive/diversifying selection, but differently among the three evolutionary pathways described. Using this extended sequence dataset, we were able to detect eight sites under positive selection. Six sites appear to be of particular interest because of their predicted localization to the extended loops of the B30.2 domain and/or support by several computational methods. The P/S 187 position was previously identified for its effect on the interaction with GPA2. The functional importance of the other five amino acid polymorphisms observed was investigated using Agrobacterium transient transformation assays. None of these new residues, however, appears to be directly involved in Gpa2-mediated plant defence mechanisms. Thus, the P/S polymorphism observed at position 187 remains the sole variation sufficient to explain the recognition of Gp-Rbp-1 by Gpa2.