Effect of florasulam on oxidative damage and apoptosis in larvae and adult zebrafish (Danio rerio)

Florasulam is widely used for weed control in wheat fields due to its high activity and low dosage. Previous studies on florasulam have focused on soil microbial and residue determination, however, its ecotoxicity to aquatic organisms is unclear. The toxicity of florasulam was evaluated in larvae (120 h) and adult (14 and 28 d) zebrafish. After florasulam (0.1 and 1 mu g L-1) exposure, reactive oxygen species levels in larvae and adult zebrafish significantly increased and antioxidant system was activated. Florasulam induced lipid peroxidation in larvae and adult zebrafish. Florasulam did not cause DNA damage to larvae but caused DNA damage to adult zebrafish. Changes in caspase 3/8/9 genes indicated that apoptosis was induced in larvae but inhibited in adult zebrafish. By calculating integrated biomarker response, caspase 3 and malondialdehyde could be used as early warning indicators of florasulam effect on larvae and adult zebrafish, respectively. The higher the exposure concentration, the greater the toxicity of florasulam to larvae and adult zebrafish. Increasing exposure time resulted in higher toxicity to adult zebrafish. Florasulam has different toxicity at larvae and adult zebrafish. In future studies to investigate florasulam toxicity to zebrafish, different zebrafish life stages (larvae and adult) need to be studied.