Effects of tetracycline and oxytetracycline on growth and chlorophyll fluorescence in lettuce seedlings

Abstract

At present, the problem of antibiotic pollution in soil is becoming more and more serious, and antibiotics entering the soil can be absorbed by plants, causing normal physiological metabolism inhibition. In this experiment, the effects of tetracycline(TC) and oxytetracycline(OTC) on the growth of lettuce were studied. Matrix culture experiments were used to investigate the effects of different levels (0, 2, 10, 50, and 250 mg/kg) of TC and OTC on the growth of lettuce, chlorophyll fluorescence parameters, and antioxidant enzyme activities. The results showed that TC and OTC caused different degrees of inhibition on the growth of lettuce due to the different concentrations. Under antibiotic's treatment, Fv/Fm, Fv '/Fm' and Y (II) of lettuce also showed a downward trend under tetracycline(TCs) treatment, however, the non-photochemical quenching (NPQ) of absorbed light energy showed an increasing trend. TCs also inhibited the antioxidant enzyme activity of lettuce, SOD activity was reduced by 3.27 (light concentration) and 52.68% (high concentration), and POD activity was decreased by 6.27 (light concentration) to 55.86% (high concentration) compared to control. The results showed that TCs could cause oxidative stress on plant growth, which should be concerned.