Research results show that for the parent tomato there is a certain dose-dependent change in the size and weight of the fruit. More precisely, in a dose of 50 Gy, the size and weight of a tomato fruit is about 40% higher than in the control. A dose of 50 Gy was taken as a stimulating dose for a tomato in these soil and climatic conditions. It is shown that for the first generation of tomato there are no noticeable dose-dependent changes in mass and size. In other words, the effect found in the parent plant does not occur in its first generation. At the same time, if you do not take into account the minor variations, the mass and size of the experimental and control fruits are almost the same. For the parent plant, an increase in the radiation dose in the region (1–50) Gy leads first to a small and then to a sharp increase in the MDA content, and in the region (50 to 400) Gy, on the contrary, to a noticeable decrease. At the same time, the content of proline for the parent plant remains almost constant from 1 to 100 Gy, and above 100 Gy it slightly increases. It is assumed that at radiation doses below 100 Gy, the need for proline is low. Therefore, antioxidant enzymes play a major role in protecting plants from adverse conditions. In fact, at these relatively low doses, APX and CAT show high activity. However, in large doses, in all likelihood, along with SOD, there is a need for the protective role of proline and its synthesis is enhanced. It was shown that APX and CAT enzymes exhibit similar dose-dependent activity and, with high activity of these enzymes, SOD exhibits low, and with low CAT and APX activity, SOD exhibits high activity. It is assumed that antioxidant enzymes, to some extent, function in a balanced manner both among themselves and with respect to proline.