Location: Hard Winter Wheat Genetics ResearchTitle: Pyrosequencing reveals the predominance of Pseudomonadaceae in gut microbiome of a Gall Midge Author
Submitted to: Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/3/2014
Publication Date: 6/11/2014
Citation: Bansal, R., Hulbert, S., Reese, J., Whitworth, R.J., Stuart, J., Chen, M. 2014. Pyrosequencing reveals the predominance of Pseudomonadaceae in gut microbiome of a Gall Midge. Pathogens. 3(2):459-472. Interpretive Summary: The gut of insects hosts various microbes. Gut microbes perform a wide range of functions useful to the host, such as synthesizing vitamins and essential amino acids, preventing growth of harmful pathogens, and utilizing energy substrates that cannot be used directly by the host itself. Gut microbes in plant-feeding insects also play a role in insect-plant interactions. The Hessian fly is a very important insect pest of wheat. In this study, we analyzed the composition of microbes in the Hessian fly larval gut for the first time. We found that the Hessian fly larval gut hosts diverse bacteria. The composition of microbes changes in different larval stages of the insect. The research provides a foundation for future research on the roles of gut microbes in Hessian fly biology and its interaction with wheat.
Technical Abstract: Gut microbes are known to play various roles in insects such as digestion of inaccessible nutrients, synthesis of deficient amino acids, and interaction with ecological environments, including host plants. Here, we analyzed the gut microbiome in Hessian fly, a serious pest of wheat. A total of 3,654 high quality sequences of the V3 hypervariable region of the 16S rRNA gene were obtained through 454-pyrosequencing. From these sequences, 311 operational taxonomic units (OTUs) were obtained at the >97% similarity cutoff. In the gut of 1st instar, otu01, a member of Pseudomonas, was predominant, representing 90.2% of total sequences. otu13, an unidentified genus in the Pseudomonadaceae family, represented 1.9% of total sequences. The remaining OTUs were each less than 1%. In the gut of the 2nd instar, otu01 and otu13 decreased to 85.5% and 1.5%, respectively. otu04, a member of Buttiauxella, represented 9.7% of total sequences. The remaining OTUs were each less than 1%. In the gut of the 3rd instar, otu01 and otu13 further decreased to 29.0% and 0%, respectively. otu06, otu08, and otu16, also three members of the Pseudomonadaceae family were 13.2%, 8.6%, and 2.3%, respectively. In addition, otu04 and otu14, two members of the Enterobacteriaceae family, were 4.7% and 2.5%; otu18 and otu20, two members of the Xanthomonadaceae family, were 1.3% and 1.2%, respectively; otu12, a member of Achromobacter, was 4.2%; otu19, a member of Undibacterium, was 1.4%; and otu9, otu10, and otu15, members of various families, were 6.1%, 6.3%, and 1.9%, respectively. The investigation into dynamics of Pseudomonas, the most abundant genera, revealed that its population level was at peak in freshly hatched or 1 day larvae as well as in later developmental stages, thus suggesting a prominent role for this bacterium in Hessian fly development and in its interaction with host plants. This study is the first comprehensive survey on bacteria associated with the gut of a gall midge, and provides a foundation for future studies to elucidate the roles of gut microbes in Hessian fly virulence and biology.