Global food demand and insecurity are intensifying due to rapid population growth, the loss of arable land, climate change, and pollution. Among the critical challenges in global agriculture is soil salinization, in which high NaCl concentrations can severely inhibit germination and crop establishment. Cakile maritima, a halophyte from the Brassica genus, can tolerate salinity levels up to 400 mM NaCl, far exceeding the tolerance of most crops, making it a promising model for studying salt stress resistance. This study investigates the effects of seed halopriming as an effective strategy to enhance salt tolerance in C. maritima. The research evaluates germination rates, seedling establishment, mineral status, oxidative stress markers, and genetic responses under increasing NaCl concentrations. Halopriming with NaCl pre-activates the plant’s antioxidant defence mechanisms and upregulates stress-responsive genes, improving the plant’s resilience to saline conditions. While salinity caused significant physiological challenges, primed seeds demonstrated superior performance compared to non-primed controls, with enhanced germination and an improved tolerance to oxidative stress. These findings underscore the potential of halopriming as a cost-effective and sustainable technique to improve crop performance in saline environments. This study highlights the importance of advancing seed priming technologies for developing resilient crops to address global food security challenges in the face of climate change.

Soil salinity inhibits germination and seedling establishment, causing patchy crop stands, uneven growth, and poor yields. This study aims to evaluate the early-stage salinity tolerance of Brassicaceae seeds inoculated with plant growth-promoting bacterial (PGPB) strains (E1 and T7) isolated from saline soils. Non-inoculated and inoculated seeds of Lobularia maritima, Sinapis alba, and Brassica napus were cultivated under control and salinity conditions, first in agar plates to assess a germination inhibitory concentration of salt for each species and later in soil irrigated with water containing 0 or 75 mM NaCl. Our results indicate that T7 was the only strain able to increase the germination of L. maritima under saline conditions. However, an increase in shoot biomass, root length, and number of branches was observed in L. maritima and S. alba plants inoculated with T7 and in B. napus with E1. Concomitantly, those seedlings exhibited less oxidative damage and greater capacity to balance plant reactive oxygen species production. This study suggests that inoculation of seeds with halotolerant PGPB strains is a suitable strategy for improving the negative effects of salinity in the early stages. Nonetheless, the observed specific plant–host interaction highlights the need for establishing tailored PGPB–crop associations for specific unfavourable environmental conditions.

1. Summary: Salt stress triggers overlapping osmotic and ionic effects. In halophytes, rapid acclimation can obscure how early responses are coordinated across organs. The use of facultative halophytes and salt shocks provides a useful framework to resolve this transition. We investigated the first 24 h of salt shock responses in the facultative halophyte Lobularia maritima by integrating physiological, ionomic, transcriptional and phytohormonal analyses to resolve organ- and time-dependent acclimation dynamics. Salt shock induced a rapid but transient osmotic effect, with shoot turgor recovery after 8 h. This recovery was associated with sustained osmotic adjustment, proline accumulation and increased Na ⁺ levels in shoots. Conversely, photosynthetic impairment persisted beyond osmotic recovery. Salt exposure rapidly reshaped shoot and root ionomes and was associated with dynamic expression of LmSOS1 , LmNHX1 , and LmHKT1 , consistent with coordinated Na ⁺ partitioning. Oxidative responses diverged between organs; shoots maintained a stable oxidative state, while roots exhibited progressive loss of meristem viability. Abscisic acid (ABA) was strongly accumulated at all time points and emerged as the dominant regulator of early responses. These results show that early salt acclimation in L. maritima is rapid but spatially and functionally uncoupled, combining fast shoot osmotic adjustment with persistent photosynthetic constraints and increased root vulnerability.