Root Architecture Dynamics and Signal Transduction Mechanisms Regulating Mineral Nutrient Acquisition in Plants

Mineral nutrient acquisition is essential for plant growth and productivity but is often limited by heterogeneous soil nutrient availability and environmental stresses such as drought, salinity and nutrient depletion. Plants have evolved highly integrated root-based sensing and signalling systems that enable dynamic adjustment of nutrient uptake, root system architecture and metabolic processes in response to fluctuating nutrient availability and stress. Root system architecture (RSA) plays a pivotal role in determining nutrient acquisition efficiency by regulating soil exploration through modifications in root length, branching patterns, growth angles and root hair development. Nutrient-specific signalling pathways mediated by transporters, transcription factors, calcium-dependent signalling modules and phytohormones, coordinate these architectural and physiological responses. Key regulatory networks involving nitrate sensors (NRT1.1), phosphate signalling components (PHR1–SPX), potassium transport systems (AKT1–CBL–CIPK complexes) and micronutrient regulators integrate nutrient status with environmental stress cues. Under stress conditions, nutrient signalling pathways intersect with drought, salinity and temperature-responsive networks, ensuring ionic homeostasis, osmotic balance, and metabolic flexibility. Phytohormonal crosstalk involving auxin, cytokinins, abscisic acid and strigolactones further fine-tunes root growth and nutrient uptake strategies. Recent advances in high-throughput phenotyping, genomics, systems biology and genome editing have significantly enhanced our understanding of nutrient–stress interactions and revealed promising targets for improving nutrient use efficiency. This review synthesizes current knowledge on root-mediated nutrient sensing, signalling and adaptive responses under stress highlighting emerging opportunities for developing resilient crops with optimized nutrient acquisition systems in challenging environments.