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

Abstract

Global environmental changes pose severe threats to agricultural ecosystems, particularly through soil salinization, which adversely affects crop productivity and sustainability. Salt stress disrupts plant physiological processes, causing osmotic stress, ionic imbalance, and oxidative damage, thereby impairing growth and development. Understanding the mechanisms of salt tolerance and developing salt-resistant crops have therefore 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 classic Salt Overly Sensitive (SOS) signaling pathway and its central role in sodium homeostasis. We further 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 approaches combining quantitative biology, genetic engineering and genome editing technologies.