School of Life Science, Institutes of Life Science and Green Development, Hebei University, Baoding, Hebei, China.
State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, China.
Microbiol Spectr. 2022 Dec 21;10(6):e0406622. doi: 10.1128/spectrum.04066-22. Epub 2022 Nov 29.
Aphids display wing polyphenism, and the mother can produce a wingless morph for reproduction and a winged morph for dispersal. It is believed that the wingless morph is an adaptive status under favorable conditions and is determined prenatally. In this study, we have found that winged nymphs of the pea aphid, Acyrthosiphon pisum, can change from winged to wingless during normal development. Our results showed that winged nymphs could become the wingless morph by apterization in response to changes from stressful to favorable conditions. The acquired wingless aphids had higher fecundity than the winged morph. However, this process of regression from winged to wingless morph was inhibited by Serratia symbiotica. The existence of the symbiont did not affect the body mass and fecundity of adult aphids, but it increased the body weight of nymphs and temporally increased the quantity of a primary symbiont, Buchnera aphidicola. Our results showed that despite temporal improvement of living conditions causing the induction of apterization of winged nymphs, the inhibition effect of S. symbiotica on this process was activated simultaneously. This finding, for the first time, reveals that the wingless morph can be changed postnatally, which explains a novel regulating mechanism of wing polyphenism driven by external abiotic stimuli and internal biotic regulation together in aphids. Wing polyphenism is an important adaptative response to environmental changes for aphids. Endosymbionts are widespread in aphids and also confer the ability to withstand unfavorable conditions. However, little is known about whether endosymbionts are involved in the wing polyphenism. In this study, we report a new finding that winged nymphs of the pea aphid could turn into adults without wings or wing-related structures through apterization when winged nymphs escaped from stressful to favorable environments. Further analysis revealed that the facultative symbiont S. symbiotica could prevent the temporal determination of the host in wing suppression by inhibiting apterization, to enhance its spread. Our findings provide a novel angle to understanding the wing polyphenism regulation of aphids.
蚜虫表现出翅膀多态性，其母体可以产生无翅型进行繁殖和有翅型进行扩散。人们认为无翅型是在有利条件下的适应性状态，并且是在产前决定的。在这项研究中，我们发现豌豆蚜（Acyrthosiphon pisum）的有翅若虫在正常发育过程中可以从有翅变为无翅。我们的结果表明，有翅若虫可以通过化蛹响应从胁迫到有利条件的变化而变为无翅形态。获得的无翅蚜虫比有翅形态具有更高的繁殖力。然而，这个从有翅到无翅形态的回归过程被共生菌 Serratia symbiotica 抑制。共生菌的存在并不影响成蚜的体重和繁殖力，但它增加了若虫的体重，并暂时增加了初级共生菌 Buchnera aphidicola 的数量。我们的结果表明，尽管生活条件的暂时改善导致有翅若虫的化蛹诱导，但共生菌 S. symbiotica 对这一过程的抑制作用同时被激活。这一发现首次表明，无翅形态可以在产后发生变化，这解释了蚜虫外部非生物刺激和内部生物调节共同驱动的翅膀多态性的新调节机制。翅膀多态性是蚜虫适应环境变化的重要反应。共生菌广泛存在于蚜虫中，也赋予了它们抵御不利条件的能力。然而，人们对共生菌是否参与翅膀多态性知之甚少。在这项研究中，我们报告了一个新的发现，当有翅若虫从胁迫环境逃到有利环境时，豌豆蚜的有翅若虫可以通过化蛹变成没有翅膀或与翅膀相关结构的成虫。进一步的分析表明，兼性共生菌 S. symbiotica 可以通过抑制化蛹来阻止宿主在翅膀抑制方面的时间决定，从而增强其传播。我们的发现为理解蚜虫的翅膀多态性调节提供了一个新的视角。
