Epigenetic and Hormonal Modulation in Plant–Plant Growth-Promoting Microorganism Symbiosis for Drought-Resilient Agriculture

Plant growth-promoting microorganisms (PGPMs) have emerged as valuable allies for enhancing plant growth, health, and productivity across diverse environmental conditions. However, the complex molecular mechanisms governing plant–PGPM symbiosis under the climatic hazard of drought, which is critically challenging global food security, remain largely unknown. This comprehensive review explores the involved molecular interactions that underpin plant–PGPM partnerships during drought stress, thereby offering insights into hormonal regulation and epigenetic modulation. This review explores the challenges and prospects associated with optimizing and deploying PGPMs to promote sustainable agriculture in the face of drought stress. In summary, it offers strategic recommendations to propel research efforts and facilitate the practical implementation of PGPMs, thereby enhancing their efficacy in mitigating drought-detrimental effects in agricultural soils.