Protective role of exogenously supplied salicylic acid and PGPB (Stenotrophomonas sp.) on spinach and soybean cultivars grown under salt stress

•Soil salinity deteriorate growth and yield of spinach and soybean cultivars.•Exogenous application of SA and PGPB improves growth and biomass of cultivars under salt stress.•Exogenous SA and PGPB control ROS and LPO production and increased proline and protein contents under salt stress.•Exogenous protectants induced variation in the appearance of new protein bands.•PGPB is more effective salinity protectant than SA for tested cultivars.