Efficacy of Pulegone Pre-treatment in Mitigating the Oxidative Damage by NaCl Applied to Allium cepa L. Seeds

Background: Saline stress is an important environmental factor that limits the productivity of numerous agricultural crops, such as onion (Allium cepa L.), a vegetable present in gardens and used in various ways. Pulegone has been identified as a component that has a large number of biological functions. Objective: The aim of this study was to investigate the effect of pulegone (100 and 500 μg/mL) on the morphological and biochemical changes to onions induced by stressing seeds with NaCl. Methods: Soil composition, emergence percentage and its inhibition, emergence speed index (ESI), leaf and root parameters, malondialdehyde (MDA) content, free iron content and chelation/oxidation capacity (Fe²⁺) were measured following 120 days of treatment. Results: Pulegone was able to significantly improve the changes in ESI caused by saline stress, not restoring other emergence parameters. The leaf size was also improved by the pulegone, which did not affect the morphological changes of the roots. Conclusion: Our results suggest that the use of pulegone is a viable treatment to mitigate the effects of salt stress on A. cepa seeds.