Obligate symbiont involved in pest status of host insect
Obligate symbiont involved in pest status of host insect
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DOI：
10.1098/rspb.2007.0620
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发表时间：
2007-08-22
影响因子：
4.7
通讯作者：
Fukatsu, Takema
中科院分区：
文献类型：
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作者：
Hosokawa, Takahiro;Kikuchi, Yoshitomo;Fukatsu, Takema
能够有效利用农业植物的特定昆虫基因型的起源不仅是害虫控制和管理等应用领域的重要课题，而且也是进化生物学等基础学科的重要课题。传统的观点认为，这些与害虫相关的生态学性状是由昆虫基因组中编码的基因决定的。在这里，然而，我们报告说，害虫的地位，昆虫主要是由共生体基因型，而不是由昆虫基因型。一种有害的臭虫物种，Megacopta punctatissima，在作物豆类上表现良好，而一种密切相关的非有害物种，Megacopta cribraria，在植物上的卵孵化率低。当它们的专性肠道共生细菌在物种之间进行实验交换时，它们在作物豆类上的表现惊人地完全相反：有害物种的卵孵化率低，而非有害物种恢复正常的卵孵化率，表现出良好的性能。卵孵化率低是由于若虫死亡率在孵化前或孵化后，这是与共生体从非害虫蝽，无论宿主昆虫物种。我们的发现为害虫的进化起源提供了新的线索，可能会导致害虫控制和管理的新方法。
The origin of specific insect genotypes that enable efficient use of agricultural plants is an important subject not only in applied fields like pest control and management but also in basic disciplines like evolutionary biology. Conventionally, it has been presupposed that such pest-related ecological traits are attributed to genes encoded in the insect genomes. Here, however, we report that pest status of an insect is principally determined by symbiont genotype rather than by insect genotype. A pest stinkbug species, Megacopta punctatissima, performed well on crop legumes, while a closely related non-pest species, Megacopta cribraria, suffered low egg hatch rate on the plants. When their obligate gut symbiotic bacteria were experimentally exchanged between the species, their performance on the crop legumes was, strikingly, completely reversed: the pest species suffered low egg hatch rate, whereas the non-pest species restored normal egg hatch rate and showed good performance. The low egg hatch rates were attributed to nymphal mortality before or upon hatching, which were associated with the symbiont from the non-pest stinkbug irrespective of the host insect species. Our finding sheds new light on the evolutionary origin of insect pests, potentially leading to novel approaches to pest control and management.