Plant Responses and Adaptations to Salt Stress: A Review

Salinity poses a significant environmental challenge, limiting plant growth and development. To cultivate salt-tolerant plants, it is crucial to understand the physiological, biochemical, and molecular responses and adaptations to salt stress, as well as to explore natural genetic resources linked to salt tolerance. In this review, we provide a detailed overview of the mechanisms behind morphological and physiological responses triggered by salt stress, including salt damage to plants, the disturbance of cell osmotic potentials and ion homeostasis, lipid peroxidation, and the suppression of photosynthesis and growth. We also describe the physiological mechanisms that confer salt tolerance in plants, such as osmotic adjustments, reactive oxygen species (ROS) scavenging, photosynthetic responses, phytohormone regulation, and ion regulation. Additionally, we summarize the salt-stress sensing and signaling pathways, gene regulatory networks, as well as salt-tolerance mechanisms in plants. The key pathways involved in salt-stress signal perception and transduction, including Ca2+-dependent protein kinase (CDPK) cascades, the salt overly sensitive (SOS) pathway, and the abscisic acid (ABA) pathway, are discussed, along with relevant salt-stress-responsive genes and transcription factors. In the end, the important issues and challenges related to salt tolerance for future research are addressed. Overall, this review aims to provide essential insights for the future cultivation and breeding of crops and fruits.