Crosstalk between pollutant-induced ionic toxicity and plant stress signaling pathways

Ionic toxicity is a widespread consequence of soil pollution and environmental degradation, imposing profound challenges on cellular homeostasis and stress adaptation in plants. Recent evidence demonstrates that pollutant-induced ionic imbalance functions not only as a biochemical disturbance but also as a potent signaling input that interfaces with core regulatory networks, including Ca²⁺ dynamics, redox signaling, MAPK cascades, and phytohormone pathways such as ABA, JA, SA, and ethylene. This review synthesizes current advances on how plants perceive and decode ionic perturbations caused by salts, heavy metals, metalloids, and emerging contaminants, and how these signals converge on transcriptional, post-translational, and metabolic regulatory layers. We highlight multi-omics and systems-biology frameworks that reveal network-level regulators bridging abiotic and biotic stress responses. Finally, we discuss how mechanistic insights into ionic–signaling crosstalk can guide crop improvement through engineering of signaling hubs, genome editing of ion transport modules, and predictive breeding strategies. This synthesis establishes a conceptual foundation for developing resilient crop varieties capable of withstanding pollution-induced ionic stress under increasingly complex environmental conditions.