Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/2011
Publication Date: 8/16/2011
Citation: Bansal, R., Hulbert, S., Schemerhorn, B.J., Reese, J.C., Withworth, J.R., Stuart, J.J., Chen, M. 2011. Hessian fly - associated bacteria: transmission, essentiality, and composition. PLoS One. 6(8):e23170. Interpretive Summary: Hessian fly is an important insect pest on wheat that causes stunting of seedlings and lodging of adult plants. In this study, we analyzed for the first time bacteria associated with different developmental stages of the Hessian fly. Diverse bacteria were found in Hessian fly larvae, pupae, and adults. Most of the bacteria were transferred to the next generation through eggs (maternal transmission). Elimination of bacteria from the insect through antibiotics resulted in high mortality of larvae, suggesting that symbiotic bacteria were essential for the insect to survive on wheat seedlings. Similar bacteria were also found in Hessian fly-infested wheat, suggesting that Hessian fly larvae transmit bacteria into plant tissue, and that these transmitted bacteria may play a role in the wheat-Hessian fly interaction. This research provides a foundation for future research on the role of bacteria in Hessian fly biology and virulence.
Technical Abstract: Plant-feeding insects have been recently found to use microbes to manipulate host plants. Gall midges are one of the largest groups of insects that manipulate host plants extensively. In this study, we systematically analyzed for the first time bacteria associated with the Hessian fly (HF, Mayetiola destructor), an important pest of wheat and a model system for studying gall midge – plant interactions. Diverse bacteria were found in different developmental HF stages. Fluorescent in situ hybridization detected a bacteriocyte-like structure in developing eggs. Bacterial rDNA was also detected in eggs by PCR using primers that targeted to different bacterial groups. These results suggested that HF hosted different types of bacteria that were transmitted to the next generation maternally. Deprivation of bacteria from the insect through antibiotics resulted in high mortality of HF larvae, indicating that symbiotic bacteria were essential for the insect to survive on wheat seedlings. A preliminary survey identified various types of bacteria associated with different HF stages, including bacterial genera Enterobacter, Pantoea, Stenotrophomonas, Pseudomonas, Bacillus, Ochrobactrum, Acinetobacter, Alcaligenes, Nitrosomonas, Arcanobacterium, Microbacterium, Paenibacillus, and Klebsiella. Similar bacteria were also found in HF-infested wheat, suggesting that HF larvae transmit bacteria into plant tissue, and that these transmitted bacteria may play a role in the wheat-HF interaction.