Synergistic Impact of Melatonin and Putrescine Interaction in Mitigating Salinity Stress in Snap Bean Seedlings: Reduction of Oxidative Damage and Inhibition of Polyamine Catabolism

While the individual influences of melatonin (MT) and polyamines (PAs) have been widely studied under various abiotic stresses, little is known about their interaction salinity stress. In present study, salt stress applied by 50 mM sodium chloride (NaCl) on snap bean seedlings has supplemented with 20 ?M MT and/or 100 putrescine (Put) (individually in combination). The results indicated that stress, combination + Put achieved highest significant increase shoot fresh dry weight, chlorophyll (Chl a), Chl a b, carotenoids, total soluble sugars, proline, K, Ca, cell membrane stability index (CMSI), as well catalase (CAT) peroxidase (POX) activities. This improvement was associated an obvious decrease Na, Na/K ratio, oxidative damage reducing leaf contents methylglyoxal (MG), hydrogen peroxide (H2O2), rate lipid peroxidation (malondialdehyde; MDA). Moreover, demonstrated activities diamine oxidase (DAO) polyamine (PAO) leading to reduction oxidation. Meanwhile, individually gave relative water content (RWC), superoxide dismutase (SOD), ascorbate (APX). Conclusively, treatment could degradation enhance tolerance seedlings.