Molecular and Physiological Responses of Plants to Salinity and Drought Stress: Implications for Crop Improvement and Climate Resilience

Two of the most pervasive abiotic factors that pose a serious danger to global agricultural output and food security are salinity and drought. This chapter provides a comprehensive overview of the biochemical and physiological responses of plants to drought and salinity stress. These environmental challenges disrupt key processes such as cellular metabolism, photosynthesis, ion regulation, and water uptake, ultimately hindering plant growth and development. This chapter talks about how antioxidant systems, osmo-protectants, transcription factors, and signaling pathways can all improve stress tolerance. Interactions between drought and salinity reveal both overlapping and distinct pathways, while advances in omics approaches have identified critical genes and metabolic routes that underpin adaptation. Case examples from rice, wheat, and maize highlight the success of breeding programs and biotechnological strategies in enhancing stress resilience. The integration of molecular breeding, plant growth regulators, beneficial microorganisms, and nanotechnology further strengthens crop performance under stress. Overall, the chapter emphasizes that sustainable management of drought and salinity depends on a multi-faceted approach that blends conventional practices with modern innovations to build climate-resilient agriculture and ensure food security.