Salinity Mitigation in Tomato Using a Halophilic Endophytic Consortium by Seed Priming: From Germination to Production

Salinity is a critical agricultural threat that reduces the productivity of several crops. Tomato (Solanum lycopersicum) is the world’s second most significant horticultural commodity, which struggles due to salt concentrations in irrigation water, even in hydroponic systems. This research evaluated seed priming treatments (hydro-, halo-, bacterio-, and halo-bacteriopriming) at different phenological stages under two salinity conditions (0 and 16 mM NaCl) to improve crop production. After evaluating physiological variables and multivariate statistical analyses, this study’s main breakthroughs are: Priming treatments modified the physiological, nutritional, and productive metabolism of tomato plants. Bacterio- and halo-bacteriopriming using an endophytic and halophytic bacterial consortium reduced germination time, enhancing uniformity and synchronizing seedling emergence. Bacteriopriming enhanced N, P, Ca and Zn absorption in seedlings. In the vegetative and reproductive stages, bacteriopriming consistently increased concentrations of K, Mg, and Zn in leaves and fruits but depleted Na uptake. Improving the nutritional balance resulted in not only a higher concentration of chlorophyll but also an increase in the yield and beta-carotene concentration in tomato fruits. The results demonstrated that halo-bacteriopriming may be a biotechnological strategy for mitigating saline stress, optimizing tomato growth and nutraceutical quality, because it outperformed the plant response in all stages of development compared to the control and hydro- and haloprimed treatments.