Magnesium-mediated stress adaptation in plants: from physio-biochemical insights to climate-resilient agriculture.

Magnesium (Mg) is a vital macronutrient that underpins multiple processes essential for plant growth, development, and survival. As the central atom in chlorophyll, Mg is indispensable for photosynthesis, the foundation of crop productivity. Beyond light capture, Mg functions as a structural, enzymatic, and regulatory ion, making it a critical mediator of plant tolerance to abiotic stresses. Drought, salinity, extreme temperatures, and nutrient deficiencies continue to limit agricultural yields, yet Mg-mediated pathways can significantly mitigate their effects. By influencing photosynthesis, ion homeostasis, osmotic adjustment, antioxidative defenses, and signal transduction, Mg reinforces multiple layers of plant stress adaptation. This review consolidates current knowledge of Mg's roles in enhancing plant tolerance to adverse conditions, with particular emphasis on the molecular, physiological, and biochemical mechanisms underlying these roles. By integrating findings across different scales, it advances understanding of Mg-mediated stress adaptation and highlights its potential as a key factor in developing climate-resilient crop production systems. Unlike earlier works that have focused narrowly on Mg nutrition and photosynthesis, this review offers a holistic framework linking molecular insights to agronomic applications. Additionally, it provides future perspectives and research directions to bridge current knowledge gaps and guide innovation in crop breeding, nutrient management, and sustainable production systems.