GC/TOF-MS-Based Metabolomics Reveals Altered Metabolic Profiles in Wood-Feeding Termite Coptotermes formosanus Shiraki Digesting the Weed Mikania micrantha Kunth

SIMPLE SUMMARY: Mikania micrantha Kunth is among the most invasive weeds in the world, causing extensive damage to both natural ecosystems and agroforestry systems. Mechanical removal is one of the most effective and straightforward approaches to controlling this weed, but this results in extensive lignocellulosic waste, and effective approaches to exploiting this abundant biomass are limited. Coptotermes formosanus Shiraki is not only an important subterranean termite pest species but also a considerable decomposer with the ability to digest lignocellulose. In this study, we evaluated the effects of a diet composed of M. micrantha leaves on C. formosanus workers. The workers increased their dietary intake when fed M. micrantha leaves, with a concomitant gradual increase in mortality rate. From the metabolic profiles, changes in metabolites and their related metabolic pathways suggested that termites can utilize M. micrantha-derived lignocellulose, but their antioxidant activity and signal transduction may be suppressed. Overall, this study identified key metabolites and pathways associated with the response of these termites to dietary changes and the effect of M. micrantha on termites. ABSTRACT: Effective approaches to exploiting the biomass of the abundant invasive weed Mikania micrantha Kunth are limited. Termites have been a focus of significant attention as mediators of biomass-processing owing to their ability to digest lignocellulose. Here, the GC/TOF-MS approach was employed to assess the effects of a diet composed of M. micrantha leaves on Coptotermes formosanus workers, with the growth performance of these workers also being assessed. The workers increased their dietary intake when fed M. micrantha leaves, with a concomitant gradual increase in mortality rate. A total of 62 differentially abundant metabolites and nine significantly affected pathways were found when comparing termites fed M. micrantha leaves to pinewood. Key metabolites, including carbohydrates, polyols, 4-hydroxyphenylacetic acid, and their related metabolic pathways, suggested that termites can digest and utilize M. micrantha-derived lignocellulose. However, changes in the tryptophan metabolism, tyrosine metabolism, and sphingolipid metabolism suggest an adverse effect of M. micrantha leaves on antioxidant activity and signal transduction in termites. Overall, this study identified the key metabolites and pathways associated with the response of these termites to dietary changes and the effect of M. micrantha on termites.