Effect of iron plaque on antibiotic uptake and metabolism in water spinach (Ipomoea aquatic Forsk.) grown in hydroponic culture

Ferrous ion was added to the culture solution, followed by the introduction of tetracyclines (TCs), to explore the effect of iron plaque (IP) on the uptake and translocation of TCs by water spinach (Ipomoea aquatic Forsk.). The adsorption amount of TCs on the root surface positively correlated with the amount of IP, except for doxycycline and minocycline. The bioconcentration factor of TCs in roots increased and fitted well with the amount of IP. The concentration of TCs in acrial tissues was three to four orders of magnitude lower than that in roots, and the translocation factor of TCs also fitted well with the amount of IP in a negative linear relationship. Furthermore, IP significantly influenced the metabolism of TCs in water spinach. The accumulation of TC metabolites increased with the increment of IP in roots rather than in acrial tissues, which showed the significance of IP in the metabolism and accumulation of TCs in aquatic plants. Therefore, the metabolism of TCs should not be ignored if IP is induced on the root surface, and the distribution of metabolites should be taken into consideration for the risk assessment and antibiotic pollution control for aquatic plants.

Automated summary

Iron plaque (IP) in water spinach was found to have an impact on the uptake and translocation of tetracyclines (TCs), with the amount of IP positively correlating with the bioconcentration factor of TCs in roots and the accumulation of TC metabolites. The concentration of TCs in aerial tissues was significantly lower than in roots, showing a negative correlation with the translocation factor of TCs. The study suggests that metabolism of TCs in aquatic plants should not be overlooked when assessing the risk of antibiotic pollution.