Salt Stress in Wheat: Effects, Tolerance Mechanisms, and Management

Soil salinity is a major constraint to global wheat (Triticum aestivum L.) production, adversely affecting crop growth and development. Despite this challenge, traditional breeding methods and management practices have struggled to keep pace with the increasing demand for grain crops. Key obstacles include insufficient understanding of sodium (Na⁺) storage mechanisms in wheat plants, limited exploration of the available gene pool, ineffective crop management techniques, a lack of effective screening methods, and overemphasis on excluding Na⁺ strategies. However, enhancing carbon metabolism efficiency, increasing accumulation of osmotic substances, improving antioxidant system efficiency, hormonal regulation, and reducing Na⁺/K⁺ ratios have shown promise in enhancing wheat growth and production under salinity stress. Effective salt stress management strategies also involve modulating root architecture, promoting plant growth through mechanisms such as (i) improved control over Na⁺ movement, (ii) K⁺ selectivity over Na⁺, (iii) stable osmotic potential, (iv) ionic homeostasis, and (v) increased energy provision for root growth compared to shoot growth. Additionally, plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi can further enhance the salinity tolerance by improving plant nutrition and soil fertility. This review comprehensively examines the impact of salt stress on wheat physiology including germination, root development, growth, nutrient uptake, light harvesting, carbon metabolism, and the amino acid profile. It also explores key tolerance mechanisms such as osmoregulation, ion homeostasis, apoplastic acidification, and antioxidant defense systems, offering valuable insights into effective management strategies to improve salt tolerance in wheat.