Parental glyphosate exposure primes tomato offspring for enhanced growth and stress tolerance

Pesticide application has been a common and effective approach of ensuring agricultural productivity, despite the growing concern about their environmental impacts. Although the acute effects of soil residues of the herbicide glyphosate (GLY) have been demonstrated on non-target plants, its long-term consequences are still unknown. Hence, this study aimed to determine if GLY can prompt an intergenerational response in crops, using tomato plants (Solanum lycopersicum L.) as a model. Seeds from parental plants (F0) exposed to GLY (0, 2.5, and 5.0 mg/kg; F0_CTR, F0_GLY2.5, and F0_GLY5.0, respectively) were germinated and then subjected to GLY exposure (0, 1.25, and 2.5 mg/kg) for 30 days, to analyse the intergenerational response in terms of biometrical growth, oxidative stress indicators, and antioxidant metabolism. While GLY affected root and shoot growth, regardless of plant provenance, plants from GLY-exposed parents showed less growth inhibitions, particularly in roots at the lowest dosage (1.25 mg/kg). Moreover, the enhancement of the antioxidant capacity in F0_CTR plants' - reflected by increased proline content and enzymatic activity - was not enough to prevent oxidative damage, as evidenced by increased H₂O₂ concentrations and lipid peroxidation. In contrast, plants of GLY-treated parents showed no signs of oxidative disorders and exhibited a reduced need to enhance enzymatic activity; the exception was catalase, whose activity increased in F0_GLY5.0 plants under 2.5 mg/kg GLY. Overall, plant response to GLY depended on both their own exposure concentration and that of their parents, suggesting an intergenerational response to GLY soil residues and providing important data for future risk evaluations.