Genome scans on experimentally evolved populations reveal candidate regions for adaptation to plant resistance in the potato cyst nematode Globodera pallida
Genome scans on experimentally evolved populations reveal candidate regions for adaptation to plant resistance in the potato cyst nematode Globodera pallida
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DOI：
10.1111/mec.14240
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发表时间：
2017-09-01
影响因子：
4.9
通讯作者：
Montarry, J.
中科院分区：
文献类型：
--
作者：
Eoche-Bosy, D.;Gautier, M.;Montarry, J.
提高抗性耐受性涉及到能够预测病原菌种群的适应速度。确定病原菌对植物抗性适应的遗传基础是更好地理解和预测这一现象的有用步骤。灰飞虱是马铃薯的一种主要害虫，其抗性QTL为GpaV(Vm)。然而，由于苍白球虫种群能够在几代内适应这种抗性，其持久性受到威胁。本研究的目的是通过结合实验进化和高密度基因组扫描来研究参与抗性破坏的基因组区域。我们对来自两个独立群体的个体池(Pool-Seq)进行了全基因组重测序，这些个体来自于两个独立的群体，这些群体在感病和抗病马铃薯品种上进行了实验进化。大约160万个SNPs被用来进行基因组扫描，使用最近的一项模型测试，以进行适应性分化和与特定于人群的协变量的关联。我们确定了275个异常值，并对其中31个进行了基因环境调查，其中31个异常值也显示适应谱系的多样性显著降低。一些候选基因组区域含有编码效应物的基因，并富含SPRYSECs，在孢囊线虫中已知参与致病和(A)毒力。经过验证的候选SNPs将提供一个有用的分子工具来跟踪自然群体中的毒力等位基因频率，并制定有效的策略来利用马铃薯的抗性，使其耐久性最大化。
Improving resistance durability involves to be able to predict the adaptation speed of pathogen populations. Identifying the genetic bases of pathogen adaptation to plant resistances is a useful step to better understand and anticipate this phenomenon. Globodera pallida is a major pest of potato crop for which a resistance QTL, GpaV(vm), has been identified in Solanum vernei. However, its durability is threatened as G. pallida populations are able to adapt to the resistance in few generations. The aim of this study was to investigate the genomic regions involved in the resistance breakdown by coupling experimental evolution and high-density genome scan. We performed a whole-genome resequencing of pools of individuals (Pool-Seq) belonging to G. pallida lineages derived from two independent populations having experimentally evolved on susceptible and resistant potato cultivars. About 1.6 million SNPs were used to perform the genome scan using a recent model testing for adaptive differentiation and association to population-specific covariables. We identified 275 outliers and 31 of them, which also showed a significant reduction in diversity in adapted lineages, were investigated for their genic environment. Some candidate genomic regions contained genes putatively encoding effectors and were enriched in SPRYSECs, known in cyst nematodes to be involved in pathogenicity and in (a) virulence. Validated candidate SNPs will provide a useful molecular tool to follow frequencies of virulence alleles in natural G. pallida populations and define efficient strategies of use of potato resistances maximizing their durability.