Effects of antibiotics on secondary metabolism and oxidative stress in oilseed rape seeds

Cruciferae brassica oilseed rape is the third largest oilseed crop in the world and the first in China, as well as a fertilizer-dependent crop. With the increased application of organic fertilizers from livestock manure in agricultural production in recent years, the resulting antibiotic pollution and its ecological health effects have attracted widespread attention. In this study, typical tetracycline and sulfonamide antibiotics tetracycline (TC) and sulfamethoxazole (SMZ) were used to investigate the effects of antibiotics on rapeseed quality and oxidative stress at the level of secondary metabolism on the basis of examining the effects of the two drugs on the growth of soil-cultivated rapeseed seedlings. The results showed that both plant height and biomass of rapeseed seedlings were significantly suppressed and ROS were significantly induced in rapeseed by exposure to high concentrations (2.5 mg/kg) of TC and SMZ. Carotenoids, tocopherols, and SOD enzymes were involved in the oxidative stress response to scavenge free radicals in rapeseed, but phenolic acids and flavonoids contents were decreased, which reduced the quality of the seeds to some extent.