Silicon (Si) enhances salt tolerance in sea barley (Hordeum marinum) by promoting growth, detoxifying reactive oxygen species, and stimulating antioxidant defense mechanisms

Salinity is a significant environmental stress that adversely impacts plant growth and productivity, posing a significant challenge for sustainable agriculture. While the role of silicon (Si) in enhancing plant resilience against various stresses, including salinity, has been recognized, its specific effects on sea barley (Hordeum marinum) under saline conditions require further exploration. The originality of this study lies in its detailed analysis of ROS detoxification and the enhancement of antioxidant defenses, aspects that have not been extensively studied in Hordeum marinum before. This study provides novel insights into the potential of silicon (0.5 mM Na2SiO3) to mitigate the adverse impacts of salinity (150 mM NaCl) on sea barley. The findings showed that under salt stress, growth parameters, soluble protein levels, and antioxidant enzyme activities such as Superoxide Dismutase (SOD), Catalase (CAT), and Guaiacol Peroxidase (GPX) were significantly reduced. Additionally, the levels of hydrogen peroxide (H2O2) and lipid peroxidation increased under saline conditions. Interestingly, silicon supply effectively counteracted these detrimental effects by improving plant growth, water status, soluble protein content, and antioxidant enzyme activities and reducing H2O2 and malondialdehyde (MDA) contents. Importantly, this study reveals that silicon enhanced salt tolerance in sea barley, in particular through the detoxification of reactive oxygen species and the stimulation of antioxidant defense mechanisms. This study underscores the potential of incorporating silicon in agricultural practices to enhance crop resilience and productivity in salt-affected regions, thus offering significant socioeconomic benefits to the agricultural sector.