Salt Stress Responses in Salvia officinalis:Role of Antioxidants, Osmoprotectants,and Secondary Metabolites

Salinity stress negatively impacts plant growth and physiological processes, leading to reduced productivity and yield.This study examined the effects of different salt stress levels and exposure durations on Salvia officinalis, focusing on photosynthetic pigments, oxidative stress markers, osmoprotectants, and secondary metabolites.Chlorophyll a content significantly decreased with increasing salinity, with a reduction of up to 50% at 200 mM NaCl, while chlorophyll b and carotenoids remained stable, indicating a protective regulatory mechanism.Hydrogen peroxide and lipid peroxidation levels showed a biphasic response, increasing at lower salinity levels (25-50 mM NaCl), stabilizing at moderate stress (100 mM NaCl), and rising again under severe conditions (150-200 mM NaCl).Proline and soluble sugars accumulated in a dose-and time-dependent manner, with proline playing a crucial role in osmotic adjustment.Total flavonoids and phenolic content significantly increased under low to moderate salinity (25-100 mM NaCl) and short-term exposure, emphasizing their role in antioxidant defense.These findings suggest that S. officinalis employs a complex adaptive strategy involving pigment regulation, oxidative stress mitigation, osmoprotectant accumulation, and secondary metabolite biosynthesis to address salinity stress.Further research is necessary to clarify the regulatory mechanisms behind these responses.