Abstract <p>Salinity is a leading cause of crop failures worldwide and a major threat to global food security. Application of biostimulants showed a high potential to become a valuable strategy for plant adaptation to adverse growth conditions, especially salinity. This attempt was carried out to evaluate the efficiency of <i>Serendipita indica</i> and phenylalanine on physio-biochemical traits of purslane (<i>Portulaca</i> <i>oleracea</i> L.) plant under salt stress. In this direction, a greenhouse study was conducted as a factorial experiment in a completely randomized design. The investigated factors were NaCl concentrations (0, 100 and 200 mM), fungus inoculation (with or without inoculation of <i>S. indica</i>) and foliar spray of phenylalanine (0, 100 and 200 mg L^–1). Our results demonstrated that the treatment of purslane plants with <i>S. indica</i> and phenylalanine significantly mitigated the harmful effects of salt stress, with more pronounced anti-stress effects observed in simultaneously inoculated plants. Additionally, the activity of antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT), was significantly enhanced in biostimulant-treated plants, particularly in CAT activity. Moreover, the biostimulants positively influenced cell membrane integrity, reduced lipid peroxidation, and enhanced osmotic stress tolerance in purslane plants. Furthermore, the application of biostimulants increased the accumulation of proline, an osmoprotectant solute, which aids in regulating the osmotic potential of cells and scavenging excess reactive oxygen species. The findings of this study emphasize the potential of <i>S. indica</i> and phenylalanine in improving plant resilience to salinity stress and their positive effects on secondary metabolite contents.</p>