Symbionts modify interactions between insects and natural enemies in the field.
Symbionts modify interactions between insects and natural enemies in the field.
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DOI：
10.1111/1365-2656.12586
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发表时间：
2016-11
期刊：
影响因子：
--
通讯作者：
Godfray HC
中科院分区：
文献类型：
--
作者：
Hrček J;McLean AH;Godfray HC
真核生物通常是可遗传共生细菌群落的宿主，其中许多对宿主的生存和繁殖并不是必需的。有实验室证据表明，这些兼性共生体可以提供有用的适应能力，例如增加对天敌的抵抗力。然而，当寄主受到一系列自然寄生虫和病原体的攻击时，我们不知道共生体如何影响寄主的适应性。在这里，我们测试了两种保护性共生体--昆虫区和防御汉密尔顿氏菌--在自然条件下是否提高了它们的寄主豌豆蚜(Acyrthosiphon Pisum)的适合度。我们将两个豌豆蚜虫品系的实验种群放置在五个潮湿的草甸地点，每个品系都有或没有共生体，以使它们暴露在敌人物种的自然集合中。然后取回这些蚜虫，并评估由寄生蜂、真菌病原体和其他原因造成的死亡率。我们发现，Regiella和Hamiltonella都减少了被特定天敌杀死的蚜虫比例，在实验室和笼子实验中，它们被证明对这些天敌具有保护作用。然而，由于其他天敌死亡率的增加和携带共生菌的成本，这一优势被抵消(哈密尔顿属)或逆转(区域属)。因此，共生体通过改变不同天敌的相对成功程度来影响群落结构。我们的结果表明，保护性共生体不一定对宿主有利，甚至可能表现得更像寄生虫而不是互助者。然而，细菌共生体可能在决定食物网的结构和动态方面发挥重要作用。
Eukaryotes commonly host communities of heritable symbiotic bacteria, many of which are not essential for their hosts' survival and reproduction. There is laboratory evidence that these facultative symbionts can provide useful adaptations, such as increased resistance to natural enemies. However, we do not know how symbionts affect host fitness when the latter are subject to attack by a natural suite of parasites and pathogens. Here, we test whether two protective symbionts, Regiella insecticola and Hamiltonella defensa, increase the fitness of their host, the pea aphid (Acyrthosiphon pisum), under natural conditions. We placed experimental populations of two pea aphid lines, each with and without symbionts, in five wet meadow sites to expose them to a natural assembly of enemy species. The aphids were then retrieved and mortality from parasitoids, fungal pathogens and other causes assessed. We found that both Regiella and Hamiltonella reduce the proportion of aphids killed by the specific natural enemies against which they have been shown to protect in laboratory and cage experiments. However, this advantage was nullified (Hamiltonella) or reversed (Regiella) by an increase in mortality from other natural enemies and by the cost of carrying the symbiont. Symbionts therefore affect community structure by altering the relative success of different natural enemies. Our results show that protective symbionts are not necessarily advantageous to their hosts, and may even behave more like parasites than mutualists. Nevertheless, bacterial symbionts may play an important role in determining food web structure and dynamics.
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影响因子：
6.7
作者：
Martinez J;Ok S;Smith S;Snoeck K;Day JP;Jiggins FM
通讯作者：
Jiggins FM
影响因子：
4
作者：
Brisson, Jennifer A.;Stern, David L.
通讯作者：
Stern, David L.
DOI：
10.1126/science.1259504
发表时间：
2015-09-04
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Johnson PT;de Roode JC;Fenton A
通讯作者：
Fenton A
影响因子：
6.7
作者：
Ahmed MZ;Li SJ;Xue X;Yin XJ;Ren SX;Jiggins FM;Greeff JM;Qiu BL
通讯作者：
Qiu BL
影响因子：
2.2
作者：
Montllor, CB;Maxmen, A;Purcell, AH
通讯作者：
Purcell, AH