A review of approaches to enhance salt stress tolerance in cotton by genetic engineering

Due to climate change, deserts are expanding, water reservoirs are drying, soil erosion is becoming more serious, and salinity areas are expanding worldwide. Among these disasters, soil salinization is one of the serious issues that affect agricultural production, with significant effects on plant development. Although plants have a solid adaptation to severe environmental conditions, their vulnerability to some abiotic stresses is still preserved in the plant genome. Cotton is a salt stress-tolerant crop among other main cash crops. However, its tolerance is limited in overwatered soil conditions or water-deficient soil. Several research investigations have been carried out to date to better understand salinity stress responses in various cotton species. The accumulation of salt due to irrigation-dependent practices exerts an adverse impact on crop productivity. However, this deleterious effect can be mitigated through a comprehensive understanding of the mechanisms by which certain plants flourish under saline conditions. Over the past few decades, there has been a notable augmentation in mechanistic comprehension, leading to the initiation of discovery-oriented methodologies aimed at discerning the genetic determinants of salt tolerance. Recent studies are showing the results of the manipulation of some important genes and proteins for salt tolerance using modern approaches. The identification of salt-resistance genes from salt-tolerant germplasm resources plays an essential role in improving the yield of cotton in saline soils. In this paper, we reviewed what has been achieved in cotton in terms of the development of its salt tolerance using genetic engineering.