Abiotic stress conditions like salinity, drought, and climate change threaten agriculture and food security worldwide. Drought and salt stress alleviation in plants might be substantially facilitated by plant growth-promoting bacteria (PGPB). The main research questions addressed were: Do the selected native PGPB strains tolerate abiotic stress such as pH variation, salt, and drought stress under in vitro conditions? Do native PGPB strains and a reduced rate of NPK chemical fertilization improve tomato seedling growth parameters compared to seedlings given 100%NPK? Two endophytic bacteria isolated from the roots of mangroves in the United Arab Emirates, Bacillus wiedmannii (S1) and Bacillus licheniformis (S2), were used to inoculate the plants. The strains and their mixture underwent tolerance testing to abiotic stresses, including pH, salinity, and drought stress. To induce salt stress, 100 mM NaCl solution was applied to the tomato plants after germination in the pot experiment. During the last two weeks of the study, plants were not irrigated to initiate drought stress.

A fully randomised design with three replicates demonstrated that the PGPB strains could improve the digital biomass, leaf area, plant height, greenness average, and the normalized digital vegetation index under induced saline and drought conditions. Inoculated plants that were exposed to drought stress exhibited enhanced levels of digital biomass (Figure 1a), leaf area, plant height, average greenness, and normalized digital vegetation index by 102%, 75%, 15%, 20%, and 2%, respectively compared to plants that received the complete dose of NPK fertilizer during drought stress. Digital biomass (Figure 1b), leaf area, plant height, and normalized digital vegetation index were higher in PGPB-inoculated plants when subjected to salt stress by 87%, 37%, 39%, and 21%, respectively, compared to plants receiving 100% NPK. This study concluded that mangrove-derived PGPB could encourage tomato seedlings' growth and resilience to salt and drought stress under minimum chemical fertilizer application.