Glyphosate escalates horizontal transfer of conjugative plasmid harboring antibiotic resistance genes

ABSTRACT

Glyphosate has been frequently detected in water environments because of the wide use for controlling weed in farm lands and urban areas. Presently, the focus of the majority of studies is placed on the toxicity of glyphosate on humans and animals. However, the effects of glyphosate on horizontal transfer of conjugative plasmid carrying antibiotic resistance gene (ARG) are largely unknown. Here, we explored the ability and potential mechanism of glyphosate for accelerating horizontal transfer of conjugative plasmid-mediated ARG. The results showed that glyphosate can effectively boost horizontal transfer rate of conjugative plasmid carrying ARG. The possible mechanism analysis demonstrated that over-production of reactive oxygen species and reactive nitrogen species effectively regulated expression levels of bacterial outer membrane protein and conjugative transfer-related genes, thereby resulting into elevated horizontal transfer rate of plasmid-mediated ARG. In conclusion, this study casts new understanding into the biological effects of glyphosate on ARG.

GRAPHICAL ABSTRACT

KEYWORDS:

• Glyphosate
• reactive oxygen species
• reactive nitrogen species
• antibiotic resistance gene
• horizontal transfer

Research highlights

Glyphosate promotes production of ROS and RNS.

ROS and RNS enhance bacterial OMP expression.

ROS and RNS regulate conjugative transfer-related genes.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by grants from the Science and Technology Research Project of Hebei Province Higher Education (QN2020242); Natural Science Foundation of Hebei Province (C2020207012); Science Research and Development Program of Hebei University of Economics and Business (2020YB14); and National Natural Science Foundation of China (81903282).