Location: Hard Winter Wheat Genetics ResearchTitle: A horizontal gene transfer led to the acquisition of fructan metabolic pathway in a gall midge
|CHENG, XIAOYHAN - Kansas State University|
|GRACES-CARRERA, SANDRA - National Institute Of Agriculture Research|
|WHITWORTH, R.JEFF - Kansas State University|
|PARK, YOONSEONG - Kansas State University|
Submitted to: Advanced Biosystems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2020
Publication Date: 2/21/2020
Citation: Cheng, X., Graces-Carrera, S., Whitworth, R., Fellers, J.P., Park, Y., Chen, M. 2020. A horizontal gene transfer led to the acquisition of fructan metabolic pathway in a gall midge. Advanced Biosystems. https://doi.org/10.1002/adbi.201900275.
Interpretive Summary: Hessian fly is an important insect pest of wheat that causes stunting and lodging. In this study, we found that Hessian fly has at least ten genes for enzymes that digest fructan, which is a storage polymer of fructose in plants. Most animals do not have enzymes that digest fructans. The ten genes were most similar to those from bacteria. The results indicate that an ancient horizontal gene transfer from bacteria to Hessian fly was followed by gene duplication and possibly functional specialization of the ten copies. Deeper understanding of the carbohydrate metabolism of Hessian fly could lead to innovative methods of control.
Technical Abstract: Fructans, which are fructose polymers, are used as energy reserves by microbes and plants but not by animals. Here, we report that the gall midge Mayetiola destructor, and likely other herbivorous animal species, gained the ability to utilize dietary fructans directly as storage polysaccharides by assimilating a bacterial metabolic pathway via horizontal gene transfer (HGT) followed by gene expansion and differentiation. Multiple genes encoding levanases/inulinases originating from a bacterium showed high expression levels and enzymatic activities in different tissues, including nondigestive fat bodies and eggs, both of which contained significant amounts of fructans. This study provides evidence of an HGT event that led to adaptive evolution and reshaping of the endogenous metabolism of an insect and is likely common in other herbivorous animal species.