Glyphosate is among the world’s most commonly used herbicides in agriculture and weed control. In the past decade, research has come forth suggesting that agrochemical use could have unintended consequences for non-target organisms, such as the honey bee (Apis mellifera L.), the earth’s most prominent insect pollinator. Hemolymph is the only biofluid in the honey bee that circulates in the insect body which can provide critical information for the metabolite response after glyphosate exposure. Metabolomics of honey bee hemolymph can provide overall biological functioning of the honey bee at the molecular level in response to an external stressor such as glyphosate, however, few studies have been focused on this area. In this study, 1H NMR-based metabolomics was applied to investigate the effects of glyphosate on Apis mellifera L. under a general herbicide application concentration over a course of 10 days. As a result, the metabolic profiling of Apis mellifera L. was significantly affected at day 2 when no physical behavior difference could be observed. Four essential amino acids leucine, lysine, valine, and isoleucine showed downregulation with significant difference (p&lt;0.05). The high perturbation of the four essential amino acids could be a sign of the honey bee’s stress response to the glyphosate by balancing the cell osmolytes. The metabolic profiling was not separated very well at day 5 which indicating a self-balancing process of the honey bees. However, after 10 days of treatment, the non-essential amino acid proline was notably downregulated. Proline has been linked to flight metabolism in honey bees, along with sucrose which is the primary metabolic source for flight. The reduced levels of both proline and sucrose in the day 10 group suggest that metabolic priority was shifted away from flight and redirected to more vital processes. The results of this study demonstrate that sublethal concentrations of glyphosate likely have a long-term effect on the regulation of essential metabolites related to honey bee development and fitness.

Metabolomic analysis of honey bee (Apis mellifera L.) response to glyphosate exposure

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.