Genetic Treasures from Halophytes: Unlocking Salt Stress Tolerance Genes

Halophytes, renowned for their ability to thrive in highly saline conditions, are considered valuable germplasm for saline agriculture. The global issue of salinity is exacerbated by factors such as limited rainfall, inadequate irrigation systems, saltwater intrusion, water pollution and other environmental influences, leading to an expansion of salt-affected areas. The intricate mechanisms behind salinity stress tolerance involve interconnected pathways working in coordination. Despite the identification of numerous salt-responsive genes in halophytes, the search for other genes in salt stress that can effectively regulate the physiology of plants remains ongoing. Halophytes hold great potential as sources of salt-responsive genes and promoters. Known genes, including antiporters, ion channels and antioxidant-encoding genes, as well as novel genes, have been isolated from halophytes and investigated for their potential to impart stress tolerance to crop plants. The observation has revealed that stress serves as a trigger for salt sensors, which in turn initiates stress tolerance mechanisms encompassing diverse signalling proteins, differential expression of multiple genes and, ultimately, the unique or combined effects of stress-responsive genes. This chapter highlights the significance of halophytes as an excellent resource for identifying salt-responsive genes that can be harnessed for developing salinity tolerance in crop plants through genetic engineering.