Insecticide applications to soil contribute to the development of Burkholderia mediating insecticide resistance in stinkbugs
Insecticide applications to soil contribute to the development of Burkholderia mediating insecticide resistance in stinkbugs
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DOI：
10.1111/mec.13265
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发表时间：
2015-07
影响因子：
4.9
通讯作者：
Kanako Tago;Y. Kikuchi;Sinji Nakaoka;Chie Katsuyama;M. Hayatsu
中科院分区：
文献类型：
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作者：
Kanako Tago;Y. Kikuchi;Sinji Nakaoka;Chie Katsuyama;M. Hayatsu
一些土壤伯克氏菌菌株能够降解有机磷杀虫剂，并与臭虫建立共生关系，使寄主昆虫对杀虫剂产生抗性。然而，共生降解伯克霍尔德菌在自由生活环境中适应非营养盐的生态学尚不清楚。我们假设施用杀虫剂会影响降解杀虫剂的伯克霍尔德菌的动力学，从而控制共生降解伯克霍尔德菌从土壤向臭虫的传播。本研究利用微生态系统研究了处理过氮肥的土壤中可培养伯克霍尔德菌（即共生和非共生氮肥降解菌和非降解菌）的密度和多样性的变化。在5次施用农药的孵育过程中，降解菌的密度从不到检测限增加到106个/g左右。随着降解生物密度的增加，优势种数量呈下降趋势；最终，一个物种占了优势。这一过程可以根据竞争排斥原理用Vmax和Km值来解释降解菌对硫磷的代谢。我们对从微生物中分离的代表性菌株进行了系统发育分析，并评估了它们与臭蝽建立共生关系的能力。将与步行者病菌建立共生关系的菌株归为一类，其中包括通常从臭虫中分离出来的共生体。集群外的菌株不一定与宿主相关联。在土壤降解动力学的初始阶段，群落中的降解物占主导地位。因此，只需少量施用灭虫硫磷就可以使共生降解物与宿主结合，并可能导致共生介导的杀虫剂抗性的出现。
Some soil Burkholderia strains are capable of degrading the organophosphorus insecticide, fenitrothion, and establish symbiosis with stinkbugs, making the host insects fenitrothion‐resistant. However, the ecology of the symbiotic degrading Burkholderia adapting to fenitrothion in the free‐living environment is unknown. We hypothesized that fenitrothion applications affect the dynamics of fenitrothion‐degrading Burkholderia, thereby controlling the transmission of symbiotic degrading Burkholderia from the soil to stinkbugs. We investigated changes in the density and diversity of culturable Burkholderia (i.e. symbiotic and nonsymbiotic fenitrothion degraders and nondegraders) in fenitrothion‐treated soil using microcosms. During the incubation with five applications of pesticide, the density of the degraders increased from less than the detection limit to around 106/g of soil. The number of dominant species among the degraders declined with the increasing density of degraders; eventually, one species predominated. This process can be explained according to the competitive exclusion principle using Vmax and Km values for fenitrothion metabolism by the degraders. We performed a phylogenetic analysis of representative strains isolated from the microcosms and evaluated their ability to establish symbiosis with the stinkbug Riptortus pedestris. The strains that established symbiosis with R. pedestris were assigned to a cluster including symbionts commonly isolated from stinkbugs. The strains outside the cluster could not necessarily associate with the host. The degraders in the cluster predominated during the initial phase of degrader dynamics in the soil. Therefore, only a few applications of fenitrothion could allow symbiotic degraders to associate with their hosts and may cause the emergence of symbiont‐mediated insecticide resistance.