Brassinosteroids and drought-tolerant rhizobacteria synergy improves drought resilience of okra (Abelmoschus esculentus L.) under field conditions

Water scarcity is a main problem in agriculture, disrupting plant-water interactions and increasing oxidative stress, which negatively impacts crop productivity. The research aimed to evaluate the synergistic effect of pre-isolated and characterized IAA-producing bacterial strains ZE15 ( Bacillus subtilis ) and ZE11 ( Paenibacillus sp.) with Brassinosteroid (BR 10⁻⁸ M) under drought stress conditions. The results confirmed that the ZE15+ZE11 consortium inoculated with seed and foliarly applied BR considerably increased the okra growth and yield. Under both normal and drought stress, shoot dry weight (30 and 30%), root dry weight (34 and 33%), and SPAD (19 and 18%), respectively, significantly improved when ZE15+ZE11 and BR were applied over the control. While the enzymatic activities, viz. SOD (29 and 30%), APX (30 and 31%), and CAT (28 and 30%) were also significantly increased by T7 under control and drought conditions, respectively. Yield parameters also improved with the application of T7 treatment, including the number of fruits per plant (45 and 44%) and fruit diameter (30 and 29%) significantly increased under normal and drought conditions. In conclusion, it can be stated that the IAA-producing bacterial consortium (ZE15+ZE11) and brassinosteroids’ integration significantly enhanced okra growth, physiological traits, antioxidant activity, and yield under both normal and drought conditions in a sustainable manner. Future studies should focus on testing the integration across different crops and agro-ecosystems to validate its potential for sustainable drought-resilient agriculture.