Mountain Pine Beetles Colonizing Historical and Naive Host Trees Are Associated with a Bacterial Community Highly Enriched in Genes Contributing to Terpene Metabolism
Mountain Pine Beetles Colonizing Historical and Naive Host Trees Are Associated with a Bacterial Community Highly Enriched in Genes Contributing to Terpene Metabolism
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DOI：
10.1128/aem.00068-13
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发表时间：
2013-06-01
影响因子：
4.4
通讯作者：
Raffa, Kenneth F.
中科院分区：
文献类型：
--
作者：
Adams, Aaron S.;Aylward, Frank O.;Raffa, Kenneth F.
山松甲虫（Dendroctonus ponderosae）是一种原产于北美西部的皮层下食草动物，可以通过克服宿主树木的防御来杀死健康的针叶树，其中主要包括高萜烯浓度。这些甲虫对抗有毒化合物的机制尚不清楚。在这里，我们探讨了一个组成部分的假设，甲虫相关的细菌共生体有助于D。ponderosae通过协助萜烯解毒来克服树木的防御。这种共生体可能会促进宿主树的过渡期间，目前正在推动气候变化的范围扩大。例如，这种昆虫最近突破了加拿大落基山脉的历史地球物理屏障，提供了对幼稚树宿主的访问，并与东部森林建立了前所未有的联系。我们使用不依赖培养的技术来描述与D相关的细菌群落。黄松甲虫和它们的画廊，从它们的历史主机，扭叶松，和它们的更近的主机，杂交P.扭叶松-班克松。我们发现，这些社区丰富的基因参与萜烯降解与其他植物生物质加工微生物群落相比。这些松甲虫微生物群落由假单胞菌属、Rahnella属、沙雷氏菌属和伯克霍尔德氏菌属的成员主导，并且参与萜烯降解的大多数基因属于这些属。我们的工作提供了与树皮甲虫相关的细菌群落的第一个宏基因组，并且与在皮层下环境中生存所需的树木防御解毒的潜在微生物贡献一致。
The mountain pine beetle, Dendroctonus ponderosae, is a subcortical herbivore native to western North America that can kill healthy conifers by overcoming host tree defenses, which consist largely of high terpene concentrations. The mechanisms by which these beetles contend with toxic compounds are not well understood. Here, we explore a component of the hypothesis that beetle-associated bacterial symbionts contribute to the ability of D. ponderosae to overcome tree defenses by assisting with terpene detoxification. Such symbionts may facilitate host tree transitions during range expansions currently being driven by climate change. For example, this insect has recently breached the historical geophysical barrier of the Canadian Rocky Mountains, providing access to naive tree hosts and unprecedented connectivity to eastern forests. We use culture-independent techniques to describe the bacterial community associated with D. ponderosae beetles and their galleries from their historical host, Pinus contorta, and their more recent host, hybrid P. contorta-Pinus banksiana. We show that these communities are enriched with genes involved in terpene degradation compared with other plant biomass-processing microbial communities. These pine beetle microbial communities are dominated by members of the genera Pseudomonas, Rahnella, Serratia, and Burkholderia, and the majority of genes involved in terpene degradation belong to these genera. Our work provides the first metagenome of bacterial communities associated with a bark beetle and is consistent with a potential microbial contribution to detoxification of tree defenses needed to survive the subcortical environment.