Salicornia persica is a halophyte plant. This plant has antibacterial properties. The present research is in the design of completely random levels with salinity treatment at four levels (0, 100, 200 and 400 ppm of NaCl) and iron oxide nanoparticles (0, 2 and 15 mg/ml) with three repetitions. The antibacterial investigation of the plant under treatment was done by determining the MIC and MBC against pathogenic bacteria using broth microdilution method. The results showed that the interaction effects of salinity and nanoparticles on the amount of malondialdehyde was significant, and the highest amount was related to the salinity of 400 ppm and the nanoparticle of 15 mg/ml, and the lowest value was related to the control plant under the treatment of 2 mg/ml nanoparticle, the antibacterial effect of control plant extract under the treatment of nanoparticle of 2 mg/ml showed the highest antibacterial activity compared to other treatments. The MIC results of the mentioned plant extract on E. coli, S. aureus, P. aeruginosa and S. pyogenes were reported as 0.78, 0.19, 0.78 and 0.39 mg/ml, respectively. Also, the result of MBC of plant extract on mentioned bacteria is 1.56, 0.38, 0.78 and 1.56 mg/ml, respectively. Based on the obtained results, it can be concluded that salt stress and iron nanoparticles increased the antibacterial activity of the plant. Also salinity stress and iron nanoparticles increased malondyaldehye, total phenol and anthocyanins.
