Acclimation to salinity stress through maintaining the redox status by H₂O₂ and arginine application in Vicia faba

The generation of reactive oxygen/nitrogen species under either natural or stressful conditions activates antioxidant systems to balance the redox status in plant cells. The effect of seed priming with low concentrations of H₂O₂ and/or arginine (Arg) was examined on redox status of salinity-stressed Vicia faba in the present study. Salinity stress produced H₂O₂ and caused oxidative damage to photosynthetic pigments and membrane lipids represented by reduction in chlorophyll contents and carbohydrate production, and high accumulation of malondialdehyde, denoted as oxidative distress. Under saline conditions, Arg and/or H₂O₂ priming increased the activity of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase), non-enzymatic antioxidants (phenols, flavonoids, anthocyanins and carotenoids), proline and total antioxidant activity (based on the FRAP method) followed by a reduction in the malondialdehyde content and an increase in the chlorophylls and water soluble carbohydrates contents. Altogether, the seed priming with H₂O₂ and Arg could constitute a ‘priming memory’ in seeds of V. faba, which recruited upon a subsequent salinity stress-exposure and induced stress-tolerance of primed beans trough invoking antioxidant systems.