Rice in Saline Soils: Physiology, Biochemistry, Genetics, and Management

Salt stress is an acute threat to plants, especially to field crops in irrigated and saline areas of the world. Rice is the second staple crop of the world after wheat, and its production is strongly affected by salinity. Therefore, to ensure food security, it is crucial to manage salt stress for sustainable rice production under saline conditions. Plant physiological, biochemical, and genetic characteristics play an important role in the adaptation of rice to saline environments. Further, the knowledge of the relationship among these characteristics is necessary to manage the salt stress and achieve optimal rice production. This review focuses on the response of rice to salinity stress; its physiological, biochemical, and genetic changes; its adaptation to saline soils through osmoregulation, ion homeostasis, apoplastic acidification, synthesis of antioxidants, genes, and hormonal regulations; and synthesis of stress-responsive proteins. Future research is needed on management strategies such as breeding for salt-tolerant cultivars, application of molecular markers to select salt-tolerant germplasm, potential of genetic transformation for salinity resistance, application of arbuscular mycorrhizal fungi, and plant growth-regulating rhizobacteria, nutrient management, and seed priming techniques for sustainable rice production in saline areas. In conclusion, salt stress affects metabolism and physiology of rice and reduces the agronomic yield. Therefore, development of salt-tolerant genotypes may be a prudent strategy to manage the salinity. Focused research on integration of different management options can lead to sustainable rice production in saline areas which may contribute significantly to global food security.