Influence of seed priming with NaCl on growth and biochemical responses of wheat (triticum aestivum l.) under salinity stress

Salinity constrains wheat growth through osmotic imbalance, ion toxicity, oxidative damage, and disruption of photosynthetic metabolism.This study evaluated whether 30 mM NaCl seed priming could improve the response of a wheat genotype (Triticum aestivum L., var.Halba) to 0, 100, 150, and 200 mM NaCl.A completely randomized 2 × 4 factorial experiment was conducted with three replications.Relative to their respective controls, saline treatments reduced plant height, leaf area, shoot fresh and dry mass, and total chlorophyll, although some traits showed non-monotonic differences between intermediate and severe salinity levels.Priming was associated with higher SOD activity and generally higher APX activity, although APX declined from 8.0 to 7.1 U mg⁻¹ protein between 150 and 200 mM NaCl in primed plants.CAT activity peaked at 100 mM NaCl after priming and declined at higher concentrations.Primed plants, under salinity, accumulated more proline and had lower MDA concentrations than corresponding unprimed plants, consistent with stronger osmotic adjustment and reduced lipid peroxidation.The most distinctive response was total soluble protein (TSP): primed plants maintained high TSP under moderate salinity (100-150 mM) but showed a marked decline at 200 mM, whereas unprimed plants showed the opposite trend.This pattern suggests a shift in protein allocation or turnover under severe stress, although protein identity and turnover were not measured.Overall, the data support NaCl priming as a physiological preconditioning treatment, while molecular validation and field experiments are required to establish the underlying mechanism and agronomic value.