Investigation of the effects of different ammonia concentrations on tribenuron methyl toxicity in Chara contraria

Subacute effects of different ammonia concentrations, tribenuron methyl herbicide, and their combinations on enzymatic and non-enzymatic antioxidants, TBARS, and protein contents in Chara contraria were investigated. Accordingly, the macrophyte was exposed to different ammonia concentrations alone or combined with the herbicide for 14 days. Enzyme activities of APx, DHAR, GPx, and GST and T-SH, NP-SH, PB-SH, TBARS, and protein levels were analyzed spectrophotometrically. While APx activity increased in all exposure groups compared to the control, DHAR and GPx activities decreased. GST enzyme activity decreased groups with herbicide, low ammonia concentration, and their combinations compared to the control. However, it increased in all the groups that contain the high ammonia concentration. Levels of T-SH and PB-SH did not change with respect to control in groups that they were mixed with tribenuron methyl and high concentration ammonia with herbicide. However, the low ammonia concentration increased in the group in which this concentration was given with the herbicide and high ammonia concentration group. NP-SH amounts did not change in any group. TBARS levels decreased in all the exposure groups compared to control. Protein amount increased in the low ammonia concentration group and all the herbicide combination groups. According to our results, APx and GPx activities and TBARS and thiol levels can be used as a biomarker for ammonia, tribenuron methyl and their combinations in C. contraria.