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

Salinity represents a critical agricultural threat that reduces the productivity of several crops. Tomato (Solanum lycopersicum), recognized as the world´s second most significant horticultural commodity globally, is salt-sensitive. This research evaluated seed priming treatments (hydro, halo, bacterio, and halo-bacterio) at different phenological stages under two salinity conditions (0 and 16 mM NaCl) as a biotechnological alternative to mitigate salt stress and increase production. Using physiological variables and multivariate statistical analyses, this research demonstrated that priming treatments modified the physiological, nutritional, and productive metabolism of tomato plants. Bacteriopriming, using an endophytic and halophytic bacterial consortium isolated from halophytes, enhanced germination variables and N, P, Ca and Zn absorption in seedlings. In the vegetative and reproductive stage and under stress, halo-bacteriopriming consistently enhanced concentrations of K, Mg, and Zn in leaves and fruits, but decreased Na absorption. This nutritional balance allowed not only a higher concentration of chlorophyll but also a significant increase in yield and beta-carotene concentration in tomato fruits. For the first time, this research demonstrated that the halo-bacteriopriming with this kind of bacteria is a biotechnological strategy to mitigate saline stress, optimizing not only tomato growth, but also its nutraceutical quality. It significantly outperformed the plant response in all stages of development compared to those from control, hydro, and halo-primed treatments.