Effects of combined pollution of tetracycline and sulfamethazine on tomato growth and antibiotic absorption

Food safety has raised immense concern globally. Due to the improper use of chemical fertilizers and pesticides, antibiotic pollution in vegetable land is becoming increasingly serious. In this study, the effects of single and combined pollution of tetracycline and sulfamethazine on tomato plants were studied. The results showed that tomato plants simultaneously absorbed tetracycline and sulfamethazine from soil and transferred them to leaves, stems and fruits. The contents of tetracycline and sulfamethazine in plant tissues elevated with the increase of soil antibiotics, which were higher in the growth stage than that in the late growth stage. Antibiotics exhibited the highest concentration in roots, followed by leaves, stems and fruits. At the concentrations of 25 and 50 mg/kg, both tetracycline and sulfamethazine hampered the growth and physiology of tomato in terms of photosynthetic rate, chlorophyll content, plant height and biomass. High concentration of antibiotic contamination led to the accumulation of nitrogen, phosphorus and potassium in leaves, reduced the carbon/nitrogen ratio in leaves, and reduced the vitamin C and sugar contents in fruits. Overall, our results indicated that the combined pollution of antibiotics can strengthen the impact on plant growth, physiological indicators and biomass.