Plant salt-tolerance mechanisms: Classic signaling pathways, emerging frontiers, and future perspectives

Global environmental change poses severe threats to agricultural ecosystems, with soil salinization emerging as a major constraint on crop productivity and sustainability. Salt stress disrupts plant physiological processesby inducing osmotic stress, ionic imbalance, and oxidative damage, thereby impairing growth and development. Therefore, elucidating the mechanisms underlying salt tolerance and developing salt-resistant crops have become critical for ensuring food security. This review synthesizes research from recent decades on plant responses to salt stress, with a focus on advances in the classical Salt Overly Sensitive signaling pathway and its central role in maintaining sodium homeostasis. We also discuss the emerging role of epigenetic regulation in mediating salt adaptation and the integration of salt-stress responses with other environmental cues under combinatorial stress conditions. Finally, we outline future research directions aimed at developing "environmentally intelligent" crops with enhanced salt tolerance through multidisciplinary strategies that combine quantitative biology, genetic engineering, and genome-editing technologies.