Abstract Description

Abiotic stresses such as salinity impose severe challenges on plant growth and survival by disrupting redox homeostasis and inducing oxidative stress. Marchantia polymorpha, a liverwort and basal land plant, serves as a valuable model for studying plant stress response mechanisms due to its evolutionary position and relatively simple physiology. In this study, we investigated the role of exogenous ascorbic acid (AsA), a key antioxidant, modulating redox balance in M. polymorpha exposed to salinity stress. Plants were subjected to 50 mM NaCl with or without AsA supplementation, and both physiological and biochemical responses were assessed. Salinity stress led to significant accumulation of reactive oxygen species (ROS), reduced photosynthetic efficiency, lipid peroxidation and altered antioxidant enzyme activity. Supplementation with AsA alleviated oxidative stress by reducing ROS accumulation, enhancing the activity of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase and catalase, and restoring photosynthetic activity. AsA-treated plants exhibited improved growth and survival under saline conditions compared to untreated controls. These findings highlight the role of AsA as an effective modulator of redox homeostasis in M. polymorpha under salinity stress and provide insights into conserved mechanisms of stress tolerance. Understanding such redox-based strategies not only deepens our knowledge of plant stress physiology but also offers potential applications in improving crop resilience to environmental stresses.