Inactivation of Wolbachia Reveals Its Biological Roles in Whitefly Host

Abstract

BackgroundThe whitefly Bemisia tabaci is cryptic species complex composed of numerous species. Individual species from the complex harbor a diversity of bacterial endosymbionts including Wolbachia. However, while Wolbachia is known to have a number of different roles, its role in B. tabaci is unclear. Here, the antibiotic rifampicin is used to selectively eliminate Wolbachia from B. tabaci so as to enable its roles in whitefly development and reproduction to be explored. The indirect effects of Wolbachia elimination on the biology of Encarsia bimaculata, a dominant parasitoid of B. tabaci in South China, were also investigated.Methodology/Principal FindingqRT-PCR and FISH were used to show that after 48 h exposure to 1.0 mg/ml rifampicin, Wolbachia was completely inactivated from B. tabaci Mediterranean (MED) without any significant impact on either the primary symbiont, Portiera aleyrodidarum or any of the other secondary endosymbionts present. For B. tabaci MED, Wolbachia was shown to be associated with decreased juvenile development time, increased likelihood that nymphs completed development, increased adult life span and increased percentage of female progeny. Inactivation was associated with a significant decrease in the body size of the 4th instar which leads us to speculate as to whether Wolbachia may have a nutrient supplementation role. The reduction in nymph body size has consequences for its parasitoid, E. bimaculata. The elimination of Wolbachia lead to a marked increase in the proportion of parasitoid eggs that completed their development, but the reduced size of the whitefly host was also associated with a significant reduction in the size of the emerging parasitoid adult and this was in turn associated with a marked reduction in adult parasitoid longevity.Conclusions/Significance Wolbachia increases the fitness of the whitefly host and provides some protection against parasitization. These observations add to our understanding of the roles played by bacterial endosymbionts.

The Intracellular Bacterium Wolbachia Uses Parasitoid Wasps as Phoretic Vectors for Efficient Horizontal Transmission

“…Then the three groups were used for Wolbachia qRT-PCR detection 24–72 h after they were fed or probed by parasitoids using the primers and protocols described in Xue et al [49]. …”

Simkania negevensis, an insight into the biology and clinical importance of a novel member of the Chlamydiales order

“…Simkaniaceae comprise three genera: Simkania, Fritschea and Syngnamydia; the latter two genera are reported as Candidatus strains, since they have not been yet recovered by culture. Fritschea were first identified in 2003 as endosymbionts of arthropods and are subdivided into two Candidatus species: F. bemisiae and F. eriococci (Everett et al, 2005;Thao et al, 2003;Xue et al, 2012). Syngnamydia, which also includes two Candidatus species (S. venezia and S. salmonis), were recently described as pathogens in fishes, causing epitheliocystis, a disease characterized by large cysts in the gills (Fehr et al, 2013;Nylund et al, 2015).…”

Is there a role for symbiotic bacteria in plant virus transmission by insects?

“…In addition to the primary symbiont, several secondary symbionts have been reported in whitefly populations surveyed worldwide, including Arsenophonus, Hamiltonella, Wolbachia, Rickettsia, Cardinium, Fritschea and Orientia [85][86][87]. These secondary symbionts are facultative residents and play more diverse roles in the association with whiteflies, for example by conferring resistance to insecticides [88,89] and high temperatures [90] and by protecting the insects from natural enemies [91][92][93][94]. Negative effects of secondary symbionts have also been reported.…”