NBS-LRR-mediated resistance triggered by aphids: viruses do not adapt; aphids adapt via different mechanisms.
NBS-LRR-mediated resistance triggered by aphids: viruses do not adapt; aphids adapt via different mechanisms.
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DOI：
10.1186/s12870-016-0708-5
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发表时间：
2016-01-22
影响因子：
5.3
通讯作者：
Lecoq H
中科院分区：
文献类型：
--
作者：
Boissot N;Thomas S;Chovelon V;Lecoq H
蚜虫是农作物上的一种严重害虫。通过用它们的口针探测，它们与植物相互作用，它们传播病毒，当它们到达韧皮部时，它们开始持续的摄取。许多植物对蚜虫的抗性已经被鉴定出来，其中几种已经被部署。然而，已经观察到一些阻力被打破。在甜瓜中，已在一些甜瓜产区部署了一种抗蚜虫的基因，并在某些农业系统中观察到了携带增值税的植物上的蚜群发育。VAT基因是一种NBS-LRR基因，它对棉蚜具有抗性，并且在非持续传播的病毒接种时也表现出对非持久性传播病毒的抗性。因此，我们利用蚜虫的多样性来描述对蚜虫和病毒的抗性模式，并研究了蚜虫和病毒可能适应VAT基因的机制。利用建立在感病背景中的VAT转基因品系，我们利用一组6个棉铃虫生物型描述了抗蚜性的VAT谱，以及对由蚜虫引发的病毒的抗性。这两种抗性表型之间的差异表明，蚜虫对VAT介导的抗性的适应不仅是通过无毒因子的改变，而且还通过对诱导的防御的适应。在用来自或向增值税植物的蚜虫连续接种的三种病毒进行的实验中，病毒没有进化来绕过增值税介导的抗性。我们通过用一组13个反映甜瓜自然多样性的甜瓜材料测试每一种蚜虫的生物型，证实了这两种抗性表型之间的差异。遗传研究表明，由蚜虫引发的对病毒的抗性模式由VAT基因座和至少另一个遗传距离较短的基因座上的不同等位基因控制。因此，对蚜虫引发的病毒的抗性是由一个基因簇控制的。在Flor模式下，无毒基因的变化决定了病原菌克服植物基因赋予的抗性的能力。VAT基因属于适合这种害虫/病原体-植物相互作用的抗性基因家族，我们揭示了另一种可能存在于植物与害虫或病原体之间的其他相互作用中的蚜虫适应机制。本文的在线版本(doi：10.1186/s12870-0160708-5)包含补充材料，授权用户可以使用。
Aphids are serious pest on crops. By probing with their stylets, they interact with the plant, they vector viruses and when they reach the phloem they start a continuous ingestion. Many plant resistances to aphids have been identified, several have been deployed. However, some resistances breaking down have been observed. In the melon, a gene that confers resistance to aphids has been deployed in some melon-producing areas, and aphid colony development on Vat-carrying plants has been observed in certain agrosystems. The Vat gene is a NBS-LRR gene that confers resistance to the aphid species Aphis gossypii and exhibits the unusual characteristic of also conferring resistance to non-persistently transmitted viruses when they are inoculated by the aphid. Thus, we characterized patterns of resistance to aphid and virus using the aphid diversity and we investigated the mechanisms by which aphids and viruses may adapt to the Vat gene. Using a Vat-transgenic line built in a susceptible background, we described the Vat- spectrum of resistance to aphids, and resistance to viruses triggered by aphids using a set of six A. gossypii biotypes. Discrepancies between both resistance phenotypes revealed that aphid adaptation to Vat-mediated resistance does not occur only via avirulence factor alterations but also via adaptation to elicited defenses. In experiments conducted with three virus species serially inoculated by aphids from and to Vat plants, the viruses did not evolve to circumvent Vat-mediated resistance. We confirmed discrepancies between both resistance phenotypes by testing each aphid biotype with a set of thirteen melon accessions chosen to reflect the natural diversity of the melon. Inheritance studies revealed that patterns of resistance to virus triggered by aphids are controlled by different alleles at the Vat locus and at least another locus located at a short genetic distance. Therefore, resistance to viruses triggered by aphids is controlled by a gene cluster. Under the Flor model, changes in the avirulence gene determine the ability of the pathogen to overcome the resistance conferred by a plant gene. The Vat gene belongs to a resistance gene family that fits this pest/pathogen–plant interaction, and we revealed an additional mechanism of aphid adaptation that potentially exists in other interactions between plants and pests or pathogens. The online version of this article (doi:10.1186/s12870-016-0708-5) contains supplementary material, which is available to authorized users.