Salicornia persica is a salt-loving plant. This plant has antimicrobial properties. This study performed in the design of completely random with salinity treatment at 4 levels of 0, 100, 200 and 400 ppm of NaCl and Titanium dioxide nanoparticles at concentrations of 0, 5 and 50 mg/ml, with 3 repetitions. The antibacterial investigation of the plant under stress and treatment was done by determining its MIC and MBC against bacteria using broth Microdilution method. The results showed that the interaction effects of salinity and nanoparticle on the amount of anthocyanin was significant, and the highest amount of anthocyanin was related to salinity of 400 ppm and nanoparticle of 50 mg/ml, and the lowest amount was related to salinity of 200 and nanoparticle of 5 mg/ml, the antibacterial effect of the plant extract under salinity of 200 and nanoparticle of 5 mg/ml showed the highest antibacterial activity compared to other treatments. The MIC results of the plant extract on E. coli, S. aureus, P. aeruginosa and S. pyogenes was reported as 0.78, 0.78, 0.39, 0.78 mg/ml respectively. Also, the results of MBCs of plant extract on mentioned bacteria were reported as 1.56, 0.78, 0.78 and 1.56 mg/ml respectively. Based on the obtained results, it can be concluded that salt stress and titanium dioxide nanoparticles increased the antibacterial activity of the plant. Also salinity stress and titanium dioxide nanoparticles increased malondyaldehye, total phenol and flavonoids.
