Deceptive chemical signals induced by a plant virus attract insect vectors to inferior hosts
Deceptive chemical signals induced by a plant virus attract insect vectors to inferior hosts
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DOI：
10.1073/pnas.0907191107
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发表时间：
2010-02-23
影响因子：
11.1
通讯作者：
Mescher, Mark C.
中科院分区：
文献类型：
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作者：
Mauck, Kerry E.;De Moraes, Consuelo M.;Mescher, Mark C.
以前的研究表明，媒介传播的病原体可以改变其宿主和媒介的表型，从而影响它们之间相互作用的频率和性质，对疾病的传播和传播具有重大影响。对于昆虫传播的病原体来说，寄主的气味特别有可能成为操纵的目标，因为植物和动物喂养的昆虫都使用来自寄主的挥发性化合物作为关键的觅食线索。在这里，我们记录了一种广泛存在的植物病原体黄瓜花叶病毒（CMV）对其寄主植物之一（Cucurbita pepo cv.）的质量和吸引力的影响。两种蚜虫载体，桃蚜和棉蚜。我们的研究结果表明，巨细胞病毒极大地降低了寄主植物的质量——蚜虫在被感染的植物上表现不佳，并迅速从它们身上迁移出去——但通过诱导植物挥发性混合物的释放增加了被感染植物对蚜虫的吸引力，否则与健康植物的释放相似。因此，巨细胞病毒似乎欺骗性地吸引病媒到受感染的植物上，然后它们迅速扩散，这一模式非常有利于巨细胞病毒采用的非持续性传播机制，与之前报道的需要持续取食蚜虫才能传播的持续性传播病毒的模式非常不同。我们的研究结果除了提供了一个记录的病原体诱导宿主植物质量对载体的欺骗信号的例子外，还表明传播机制是形成病原体诱导的宿主植物表型变化的主要因素。此外，我们的研究结果产生了一个普遍的假设，即当媒介传播的植物或动物病原体降低了媒介的宿主质量时，病原体诱导的宿主表型变化经常会增加媒介的吸引力，这将涉及到现有宿主位置线索的夸大。
Previous studies have shown that vector-borne pathogens can alter the phenotypes of their hosts and vectors in ways that influence the frequency and nature of interactions between them, with significant implications for the transmission and spread of disease. For insect-borne pathogens, host odors are particularly likely targets for manipulation, because both plant-and animal-feeding insects use volatile compounds derived from their hosts as key foraging cues. Here, we document the effects of a widespread plant pathogen, Cucumber mosaic virus (CMV), on the quality and attractiveness of one of its host plants (Cucurbita pepo cv. Dixie) for two aphid vectors, Myzus persicae and Aphis gossypii. Our results indicate that CMV greatly reduces host-plant quality-aphids performed poorly on infected plants and rapidly emigrated from them-but increases the attractiveness of infected plants to aphids by inducing elevated emissions of a plant volatile blend otherwise similar to that emitted by healthy plants. Thus, CMV appears to attract vectors deceptively to infected plants from which they then disperse rapidly, a pattern highly conducive to the nonpersistent transmission mechanism employed by CMV and very different from the pattern previously reported for persistently transmitted viruses that require sustained aphid feeding for transmission. In addition to providing a documented example of a pathogen inducing a deceptive signal of host-plant quality to vectors, our results suggest that the transmission mechanism is a major factor shaping pathogen-induced changes in host-plant phenotypes. Furthermore, our findings yield a general hypothesis that, when vector-borne plant or animal pathogens reduce host quality for vectors, pathogen-induced changes in host phenotypes that enhance vector attraction frequently will involve the exaggeration of existing host-location cues.