Investigation of the stimulating effects of proline on germination in two different tomato cultivars exposed to copper stress

Plants are always interacting with their environment in which they live, and they exposed to stress when the environmental conditions become severe. Excess copper creates a kind of heavy metal stress effect that causes toxic effects on plants. Proline is an antioxidant and osmolyte compound, which plays an essential role in stress tolerance in living organisms. Tomato is both an important agricultural product and an economically valuable export item for our country. In the present study, the effects of copper excess on germination of two different tomato varieties, local and certified, were investigated. Also, the mitigating effects of exogenously applied proline against copper stress during germination were investigated in the study. For this purpose, antioxidant enzyme activities such as catalase, superoxide dismutase, ascorbate peroxidase and guaiacol peroxidase were analysed in addition to basic stress parameters such as germination number, root length, relative water content, lipid peroxidation levels and hydrogen peroxide content. When the results are examined, it is concluded that proline applied at particular concentrations has a mitigating effect against copper excess.