Ciprofloxacin and glyphosate co-exposure alters soybean development and reprograms metabolic pathways

Abstract

The increasing occurrence of pharmaceutical residues and herbicides in agricultural soils raises concerns about their impactson crop development. Here, we first screened the effects of 22 emerging contaminants on soybean (Glycine max L.) germinationand subsequently assessed the individual and combined effects of ciprofloxacin (CIP) and glyphosate (G) duringearly development. A multidisciplinary strategy was applied, integrating morphophysiological measurements, stress-relatedbiomarkers, and ^1H NMR-based metabolomic profiling from germination to the R1 stage. Soybean seedlings exposed toCIP (0.10 and 1.00 mg L–1), alone or with G, showed dose-dependent phytotoxicity, with CIP 1.00 mg L–1 significantlyreducing shoot length, leaf number, and biomass. Remarkably, co-exposure with glyphosate modulated CIP-induced effectsin a parameter-dependent manner, with both attenuation and enhancement depending on the measured trait. At R1, prolineand GABA showed slight, non-significant increases, while metabolomics revealed reduced glucose and elevated alanine andsqualene, suggesting alterations in energy, amino acid, and lipid metabolism. These metabolic disruptions were attenuatedunder co-exposure. Overall, CIP significantly alters soybean physiology and metabolism, while G modulates CIP-inducedeffects in a parameter-dependent manner, showing both attenuation and enhancement depending on the evaluated trait. Thefindings highlight the ecological relevance of pharmaceutical–herbicide mixtures and demonstrate the value of metabolomicsfor detecting early biochemical responses in crops.