Transplanting drought-Protective Bacteria to enhance clove basil's (Ocimum gratissimum) drought tolerance

Modern horticulture relies heavily on chemical inputs to ensure plant growth and health. While the benefits of plant-associated microbes in promoting drought tolerance are well established, their consistent performance under field-like conditions remains limited. We hypothesize that a minimal, drought-adapted bacterial community-composed of strains isolated from resilient plants-can not only outperform single-strain inoculants, but also confer drought tolerance across plant cultivars when transplanted into a sensitive host such as clove basil. To test this hypothesis, three drought-tolerant bacterial strains from the Pseudomonas fluorescence genus were selected and their effects on clove basil (Ocimum gratissimum) plants were evaluated under severe drought stress conditions. The protectiveness of bacteria and their efficacy increased by growing the bacterial consortium size from one to three strains. A minimal community of three bacterial strains increased clove basil growth, nutrient content, stress tolerance and essential oil constituents under drought conditions. We propose that the minimal bacterial community enhance drought resilience in clove basil by boosting nutrient uptake and increasing the production of key secondary metabolites such as linalool and caryophyllene. By leveraging the potential of a minimal bacterial community, this research presents a pathway toward enhancing vegetable drought tolerance, contributing to a more sustainable and resilient horticultural practice.