An overview of salinity stress, mechanism of salinity tolerance and strategies for its management in cotton

Abstract

Salinity stress is one of the primary threats to agricultural crops resulting in impaired crop growth and development. Although cotton is considered as reasonably salt tolerant, it is sensitive to salt stress at some critical stages like germination, flowering, boll formation, resulting in reduced biomass and fiber production. The mechanism of partial ion exclusion (exclusion of Na+ and/or Cl–) in cotton appears to be responsible for the pattern of uptake and accumulation of harmful ions (Na+ and Cl) in tissues of plants exposed to saline conditions. Maintaining high tissue K+/Na+ and Ca2+/Na+ ratios has been proposed as a key selection factor for salt tolerance in cotton. The key adaptation mechanism in cotton under salt stress is excessive sodium exclusion or compartmentation. Among the cultivated species of cotton, Egyptian cotton (Gossypium barbadense L.) exhibit better salt tolerance with good fiber quality traits as compared to most cultivated cotton and it can be used to improve five quality traits and transfer salt tolerance into Upland or American cotton (Gossypium hirsutum L.) by interspecific introgression. Cotton genetic studies on salt tolerance revealed that the majority of growth, yield, and fiber traits are genetically determined, and controlled by quantitative trait loci (QTLs). Molecular markers linked to genes or QTLs affecting key traits have been identified, and they could be utilized as an indirect selection criterion to enhance breeding efficiency through marker-assisted selection (MAS). Transfer of genes for compatible solute, which are an important aspect of ion compartmentation, into salt-sensitive species is, theoretically, a simple strategy to improve tolerance. The expression of particular stress-related genes is involved in plant adaptation to environmental stressors. As a result, enhancing tolerance to salt stress can be achieved by marker assisted selection added with modern gene editing tools can boost the breeding strategies that defend and uphold the structure and function of cellular components. The intent of this review was to recapitulate the advancements in salt screening methods, tolerant germplasm sources and their inheritance, biochemical, morpho-physiological, and molecular characteristics, transgenic approaches, and QTLs for salt tolerance in cotton.

Unravelling Abiotic Stress Physiology in Cotton (Gossypium hirsutum L.): Biotechnological Interventions in Mitigating Abiotic Stress

“…This seminal work paved the way for the following studies, highlighting the relevance of genetic variety in breeding programs. [154]. A genetic investigation of drought tolerance in Egyptian cotton (Gossypium barbadense L.) yielded important insights into the heritability of drought tolerance features.…”

Applications of Virus-Induced Gene Silencing in Cotton

“…Soil salinization is one of the most urgent issues worldwide, due to its negative impact on agricultural production. It has adversely affected over 800 million hectares of arable land globally, accounting for over 6% of the world’s total agricultural land [ 48 ]. An appropriate salt concentration can serve as a nutritional component to promote cotton growth.…”

Exogenous γ-Aminobutyric Acid Can Improve Seed Germination and Seedling Growth of Two Cotton Cultivars under Salt Stress

“…This phenomenon is particularly prevalent in arid and semi-arid regions, posing a significant challenge for agricultural productivity. Among the various salts affecting soil, NaCl stands out as the most common and widely distributed [ 1 , 2 , 3 ]. In this environmental context, cotton ( Gossypium spp.…”

“…However, excessively high salt levels in the soil have varying degrees of negative effects on the entire growth period of cotton, especially during the germination and seedling stages, where cotton is more sensitive to salt stress [ 4 , 8 ]. Salt inhibits the absorption of water and nutrients by cotton seeds and seedling roots, leading to the uptake of large amounts of salts, such as Na + and Cl − , resulting in adverse effects such as osmotic stress, ion toxicity, and oxidative stress [ 3 , 8 ]. This poses the challenge of ‘difficult emergence and seedling protection’ when cultivating cotton in saline–alkali soil.…”

“…However, there is relatively limited information on the effects of GABA on improving cotton seed germination and seedling growth. Gossypium hirsutum L. is the most important cultivar in global cotton production, cultivated in over 95% of cotton-producing regions worldwide [ 3 , 4 ]. The Xinjiang region holds a significant position in the global cotton industry, especially in southern Xinjiang, where cotton cultivation covers more than two-thirds of the total cotton area in Xinjiang [ 6 , 7 , 21 ].…”