Effects of parasitism on aphid nutritional and protective symbioses
Effects of parasitism on aphid nutritional and protective symbioses
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DOI：
10.1111/mec.12550
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发表时间：
2014-03-01
影响因子：
4.9
通讯作者：
Oliver, Kerry M.
中科院分区：
文献类型：
--
作者：
Martinez, Adam J.;Weldon, Stephanie R.;Oliver, Kerry M.
昆虫通常携带可遗传的共生体，可以与食用植物或天敌相互作用。所有豌豆蚜（Acyrthosiphon pisum）都需要感染营养共生体 Buchnera，许多豌豆蚜还感染汉密尔顿氏菌（Hamiltonella），后者可以预防寄生蜂蚜虫（Aphidius ervi）。基于汉密尔顿氏菌的保护需要称为 APSE 的噬菌体，其保护水平因菌株和相关 APSE 的不同而异。包括 A.ervi 在内的内寄生物可能会从保护营养共生和抑制保护性共生中受益，而蚜虫及其遗传共生体在受到黄蜂攻击时具有一致的利益。我们研究了寄生对蚜虫营养和保护性共生体丰度的影响。首先，我们确定了与多种共生体菌株和蚜虫基因型相关的保护强度，因为这些可能会影响共生体反应。出乎意料的是，一些兼性共生体治愈的豌豆基因型对寄生具有抗性，并且抗性蚜虫品系携带没有提供额外保护的汉密尔顿氏菌菌株。易感蚜虫克隆携带保护菌株。 qPCR 估计表明，寄生显着影响 Buchnera 和 Hamiltonella 滴度，多种因素导致变异。在易感品系中，寄生导致在幼虫黄蜂出现时附近布赫内拉菌数量增加，这与寄生虫操作一致，但在抗性品系中，效果各不相同。寄生还导致 APSE 增加，随后汉密尔顿菌减少，我们讨论了这种反应与保护表型的关系。总之，我们表明寄生改变了宿主内营养和保护共生的生态，对这种拮抗相互作用中的所有参与者都可能产生重大影响。
Insects often carry heritable symbionts that negotiate interactions with food plants or natural enemies. All pea aphids, Acyrthosiphon pisum, require infection with the nutritional symbiont Buchnera, and many are also infected with Hamiltonella, which protects against the parasitoid Aphidius ervi. Hamiltonella-based protection requires bacteriophages called APSEs with protection levels varying by strain and associated APSE. Endoparasitoids, including A.ervi, may benefit from protecting the nutritional symbiosis and suppressing the protective one, while the aphid and its heritable symbionts have aligned interests when attacked by the wasp. We investigated the effects of parasitism on the abundance of aphid nutritional and protective symbionts. First, we determined strength of protection associated with multiple symbiont strains and aphid genotypes as these likely impact symbiont responses. Unexpectedly, some A.pisum genotypes cured of facultative symbionts were resistant to parasitism and resistant aphid lines carried Hamiltonella strains that conferred no additional protection. Susceptible aphid clones carried protective strains. qPCR estimates show that parasitism significantly influenced both Buchnera and Hamiltonella titres, with multiple factors contributing to variation. In susceptible lines, parasitism led to increases in Buchnera near the time of larval wasp emergence consistent with parasite manipulation, but effects were variable in resistant lines. Parasitism also resulted in increases in APSE and subsequent decreases in Hamiltonella, and we discuss how this response may relate to the protective phenotype. In summary, we show that parasitism alters the within-host ecology of both nutritional and protective symbioses with effects likely significant for all players in this antagonistic interaction.