A novel bacterium from the hottest recorded place on earth enhances maize drought tolerance through multifaceted physiological modifications.

This study investigated the potential of native rhizobacteria from the Lut Desert, one of the hottest and most arid regions on Earth, to enhance drought tolerance in Maize (Zea mays L.). Bacterial isolates were screened for abiotic stress tolerance and plant growth-promoting traits. The selected strain, THU2, which demonstrated minimal growth inhibition under drought, heat, and salinity stress, was used in comprehensive greenhouse and field experiments under both optimal and water-deficit conditions. Results revealed that THU2 inoculation significantly improved maize growth and physiological performance, increasing shoot fresh weight by approximately 40-50% under optimal conditions and by over 100% under water-deficit conditions compared to mock. Key mechanisms identified included: (1) root and xylem modifications that improved water uptake and transport; (2) stomatal regulation leading to enhanced water-use efficiency and photosynthetic rate; and (3) biochemical protection through elevated proline content (up to 53% increase) and reduced oxidative damage (up to 35% reduction in MDA). Field trials confirmed the greenhouse findings, with THU2-inoculated plants showing superior growth, higher photosynthetic efficiency, and increased yield under drought stress. This research demonstrates that the extreme-adapted bacterium THU2 is a highly effective bio-inoculant, offering a sustainable strategy to improve crop resilience in water-limited environments.