Learning from Salicornia: Physiological, Biochemical, and Molecular Mechanisms of Salinity Tolerance

Salicornia species are halophytic plants that thrive in environments with moderate to high salinity. Owing to its high nutritional value and diverse bioactive constituents, Salicornia holds promise for applications in the food, feed, pharmaceutical, cosmetic, and bioenergy sectors. Understanding its salt tolerance mechanisms is important for developing crops suited to saline soils and water. Recent studies have revealed that Salicornia adapts to salinity through diverse physiological, biochemical, and molecular strategies. Despite these advances, a comprehensive synthesis of existing knowledge remains absent, hindering its effective application in crop improvement. In this review, recent advances in the understanding of Salicornia's salinity tolerance are synthesized, with emphasis placed on key mechanisms: cell wall nano-mechanics, ion regulation and compartmentation, antioxidant defense, osmotic balance, phytohormonal control, signal transduction, transcriptional regulation, and the expression of salt-responsive proteins. The interactions among these mechanisms are also examined, along with their roles in conferring tolerance to additional abiotic stresses such as drought, submergence, and extreme temperatures. Finally, the potential applications of these findings in genetic engineering for improving salt tolerance in crops are discussed, along with proposed directions for future research to promote the use of halophytes in sustainable agriculture.