Rhizosphere dynamics and microbial mechanisms for improving plant resilience to soil salinity

The rhizosphere is a critical interface where salinity-induced ionic, osmotic, and oxidative stresses are shaped by reciprocal interactions between plant roots, soil properties, and microorganisms. The paper discusses how microbial traits governing ion transport, antioxidant capacity, hormonal signaling, and nutrient mobilization contribute to plant resilience to soil salinity and examines the physiological, molecular, and ecological basis of these interactions. Under saline conditions, changes in root architecture and exudation profiles influence the recruitment and activity of microbial communities, including halotolerant and plant-beneficial taxa capable of producing exopolysaccharides, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, siderophores, and other functional metabolites. These interactions create reciprocal feedbacks that connect microbial community assembly with root physiology, nutrient mobilization, and stress signaling. Beneficial microorganisms alleviate ionic and osmotic stress through biofilm formation, improved rhizosphere water retention, regulation of sodium (Na⁺) and potassium (K⁺) transport, and modulation of key ion transport systems involved in plant K⁺/Na⁺ homeostasis. They also influence phytohormonal networks involving indole-3-acetic acid, abscisic acid, and jasmonate, while enhancing antioxidant defenses and redox homeostasis. By integrating these interconnected processes, the review highlights the rhizosphere as a dynamic functional system in which microbial activities can reinforce plant physiological adaptation to salinity. This framework provides a basis for understanding how rhizosphere processes can be harnessed to improve plant salinity resilience and develop more effective microbiome-informed strategies for sustainable crop production in salt-affected soils.