Harnessing halophyte adaptations for salinity resilient agriculture through genetic mechanisms and crop improvement

Halophytes, constituting approximately 1–2% of global flora, represent a diverse group of salt-tolerant plant species distributed across coastal marshes, mangrove swamps, saline deserts, and inland salt flats. Their remarkable ability to survive and reproduce under extreme salinity arises from independently evolved physiological, anatomical, and genetic adaptations, making them a valuable model system for understanding salt stress resilience. Salt tolerance in halophytes is a complex polygenic trait governed by ion homeostasis, osmotic adjustment, antioxidant defense, and transcriptional regulation. Key mechanisms include sequestration of Na + into vacuoles through NHX antiporters, maintenance of K + /Na + balance by HKT and AKT transporters, accumulation of osmoprotectants such as proline and glycine betaine, and activation of ROS scavenging enzymes. Advancements in genomics and multi-omics have revealed roles of whole-genome duplication, gene family expansion, alternative splicing, and regulatory network rewiring in enhancing salinity tolerance. Species such as quinoa, Salicornia, and Atriplex are emerging as candidate crops for saline agriculture due to their nutritional value, oil content, biomass productivity, and fodder quality. Yet, domestication barriers including seed dormancy, non-uniform maturity, and limited germplasm characterization etc. downscale the wide range cultivation. Modern breeding tools, including marker-assisted selection, genomic selection, and CRISPR mediated gene editing, offer rapid strategies for improving yield-related traits while retaining stress tolerance. Furthermore, halophytes serve as genetic donors for introgression of salt tolerance loci into glycophytic crops such as rice, wheat, tomato, and barley. Transgenic interventions using antiporters and stress inducible transcription factors have demonstrated improved ion homeostasis and biomass production. Emerging microbiome assisted breeding utilizing halophyte associated endophytes provides an eco-friendly strategy for enhancing tolerance in conventional crops. Collectively, integrating halophyte physiology, omics resources, and precision breeding tools builds a promising framework for developing salinity resilient agriculture and ensuring food security on marginal lands.