Mining Halophytic Genes for Developing Salt Tolerance in Crop Plants

Soil salinity stands as one of the most severe abiotic stresses, profoundly impacting the growth and productivity of crop plants. Eventually, it intimidates food security and sustainability, hence becoming an apprehension worldwide. To cope up with the detrimental salt stress effects, plants adopt some basic mechanisms. Salt tolerance is a multigenic trait with complex mechanism. Therefore, conventional plant breeding attempts using tolerant/resistant genetic resources have limited success. A large number of salt-tolerant genes have been identified from glycophytes. However, halophytic genes involved in salt tolerance have been barely explored. The halophytes such as Atriplex, Aeluropus, Cakile, Halimione, Petrosimonia, Salicornia, Suaeda, Thellungiella, and Zoysia are the potential sources of many salt-tolerant genes. These plants can sustain under extreme salinity without any impact on their growth and development. Depending on the plant tolerance to various saline soils, these have been classified as obligate and facultative halophytes. The lack of stress-responsive key genes, capable of reshaping the physiology of plant in response to salt stress, is evident. A systematic investigation of these genes is essential to understand the molecular mechanism operating behind this. The molecular techniques, viz., genome sequencing, RNA sequencing, and position-based cloning, have been utilized for gene mining in crop plants. Some of these techniques have been discussed here to extract halophytic genes linked to salt tolerance in agricultural crops.