Mechanisms of anthocyanin-mediated salt stress alleviation and cellular homeostasis in plants

Soil salinization, an overwhelming problem exacerbated by climate change and anthropogenic activities, poses a significant threat to global food security by impairing plant growth, development, and crop productivity. Salinity stress induces osmotic, ionic, and oxidative stresses, disrupting physiological and biochemical processes in plants. Anthocyanins, a class of flavonoids, have emerged as key players in mitigating salt stress through their antioxidant properties, ROS scavenging, and regulation of stress-responsive pathways. During salt stress, ROS act as damaging agents and signaling molecules, upregulating anthocyanin-related genes to mitigate oxidative stress and maintain cellular homeostasis. Anthocyanins mitigate salt stress by regulating osmotic balance, ion homeostasis, and antioxidant defenses. Their biosynthesis is regulated by a network of structural and regulatory genes, including MYB, bHLH, and WD40 transcription factors, influenced by epigenetic modifications and hormonal signaling pathways such as ABA, JA, and SA. Advances in genetic engineering, including CRISPR/Cas9-mediated gene editing, have enabled the development of anthocyanin-rich transgenic plants with enhanced salt tolerance. For instance, transgenic plants overexpressing anthocyanin biosynthesis genes like DFR and ANS have demonstrated enhanced salt tolerance in crops such as tomatoes and rice. However, challenges such as variability in anthocyanin accumulation and stability under environmental stressors remain. This review highlights the translational potential of anthocyanins in crop improvement, emphasizing the need for integrated multi-omics approaches and field trials to validate their efficacy. By elucidating the molecular mechanisms of salt stress and anthocyanin-mediated stress alleviation, this work provides a foundation for developing resilient crops to address the growing challenges of soil salinization.