Zhang Chang-Rong, Shan Hong-Wei, Xiao Na, Zhang Fan-Di, Wang Xiao-Wei, Liu Yin-Quan, Liu Shu-Sheng
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
Sci Rep. 2015 Oct 29;5:15898. doi: 10.1038/srep15898.
Where multiple symbionts coexist in the same host, the selective elimination of a specific symbiont may enable the roles of a given symbiont to be investigated. We treated the Mediterranean species of the whitefly Bemisia tabaci complex by oral delivery of the antibiotic rifampicin, and then examined the temporal changes of its primary symbiont "Candidatus Portiera aleyrodidarum" and secondary symbiont "Ca. Hamiltonella defensa" as well as host fitness for three generations. In adults treated with rifampicin (F0), the secondary symbiont was rapidly reduced, approaching complete disappearance as adults aged. In contrast, the primary symbiont was little affected until later in the adult life. In the offspring of these adults (F1), both symbionts were significantly reduced and barely detectable when the hosts reached the adult stage. The F1 adults laid few eggs (F2), all of which failed to hatch. Mating experiments illustrated that the negative effects of rifampicin on host fitness were exerted via female hosts but not males. This study provides the first evidence of differential temporal reductions of primary and secondary symbionts in whiteflies following an antibiotic treatment. Studies that disrupt functions of bacterial symbionts must consider their temporal changes.
当多种共生体在同一宿主中共存时，选择性消除特定共生体可能有助于研究特定共生体的作用。我们通过口服抗生素利福平处理了烟粉虱复合种的地中海物种，然后研究了其主要共生体“‘候选’粉虱内共生菌”和次要共生体“‘候选’汉密尔顿氏菌”的时间变化以及宿主连续三代的适合度。在用利福平处理的成虫（F0）中，次要共生体迅速减少，随着成虫变老接近完全消失。相比之下，主要共生体直到成虫后期才受到轻微影响。在这些成虫的后代（F1）中，当宿主发育到成虫阶段时，两种共生体都显著减少且几乎检测不到。F1代成虫产卵很少（F2），且所有卵都未能孵化。交配实验表明，利福平对宿主适合度的负面影响是通过雌性宿主而非雄性宿主施加的。本研究首次证明了抗生素处理后粉虱中主要和次要共生体在时间上的不同程度减少。破坏细菌共生体功能的研究必须考虑它们的时间变化。
