Screening of microbes from hypersaline habitats reveals distinct functional modes of drought mitigation in maize

Abstract Background and aims Drought limits maize ( Zea mays L.) productivity worldwide. Microorganisms from hypersaline habitats possess traits that may mitigate water deficit through osmotic stress adaptations. We aimed to evaluate isolates from these environments as bioinputs for maize and to resolve whether their effects act via resistance (maintenance under stress) and/or resilience (recovery after rehydration). Methods We tested 65 bacterial and fungal isolates from rhizosphere sediments of halophytic plants in apicuns (hypersaline tidal flats) and salt flats. Maize was grown in non-sterile soil under greenhouse conditions with seed inoculation, irrigated initially, then exposed to progressive drought and rehydration. We measured SPAD chlorophyll index, leaf temperature, relative water content, proline, chlorophyll a, shoot dry mass, shoot-to-root ratio, and a drought visual score, and analyzed data with univariate contrasts and multivariate ordination. Results Several isolates improved performance relative to the droughted control. Resistance responses included maintenance of SPAD, moderated leaf temperature, and preserved relative water content. Resilience responses included recovery of SPAD and shoot growth after rehydration. The largest number of effective isolates belonged to Bacillaceae, notably Halobacillus and Virgibacillus . The most consistent response was observed for a Modicisalibacter isolate (Halomonadaceae), which combined thermal buffering, SPAD stability, enhanced root investment, and increased shoot biomass. Additional gains were observed with Halomonas and Aspergillus. Conclusions Hypersaline-derived microbes provide complementary functional strategies that differentially sustain maize during drought and recovery. Trait-guided screening offers a rational basis to design multi-strain inoculants targeting resistance and resilience phases under water-limited agriculture.