Abstract: Sulphur oxide is one of the most serious problems of air pollution on the environment, especially human and plant health. This study was conducted to clarify the effect of sulphur dioxide (SO2) stress on some of the biochemical characteristics of tomato plant, Lycopersicum esculentum Mill. The plants were exposed to three doses of SO2 (0, 5, 10 mg.m-3), the exposure period was inclusive to 1 and 2 hours for each day. In order to reduce the toxicity of sulphur dioxide, the plants were treated by spraying them with trehalose sugar at concentrations of 0,50 and 100 mg.L-1. The results of the experiment showed that increasing the concentration of SO2 as well as increasing its exposure led to an increase in the activity of enzyme antioxidants (superoxide dismutase, SOD; peroxidase, POD; catalase CAT) and non-enzymatic antioxidants (Proline, Vitamin C, Lycopene), while the antioxidant activities decreased when spraying trehalose, especially at concentration 100 mg.L-1. It also recorded a positive effect in mitigating the negative effects of sulphur dioxide stress.
