Salinity stress in cotton: effects, mechanism of tolerance and its management strategies

Abstract

Cotton is classified as moderately salt tolerant crop with salinity threshold level of 7.7 dS m-1. Salinity is a serious threat for cotton growth, yield and fiber quality. The sensitivity to salt stress depends upon growth stage and type of salt. Understanding of cotton response to salinity, its resistance mechanism and looking into management techniques may assist in formulating strategies to improve cotton performance under saline condition. The studies have showed that germination, emergence and seedling stages are more sensitive to salinity stress as compared to later stages. Salt stress results in delayed flowering, less fruiting positions, fruit shedding and reduced boll weight which ultimately affect seed cotton yield. Depressed activities of metabolic enzymes viz: acidic invertase, alkaline invertase and sucrose phophate synthase lead to fiber quality deterioration in salinity. Excessive sodium exclusion or its compartmentation is the main adaptive mechanism in cotton under salt stress. Up regulation of enzymatic and non-enzymatic antioxidants genes offer important adaptive potential to develop salt tolerant cotton varieties. Seed priming is also an effective approach for improving cotton germination in saline soils. Intra and inter variation in cotton germplasm could be used to develop salt tolerant varieties with the aid of marker assisted selection. Furthermore, transgenic approach could be the promising option for enhancing cotton production under saline condition. It is suggested that future research may be carried out with the combination of conventional and advance molecular technology to develop salt tolerant cultivars.

Nitrogen Enhances Salt Tolerance by Modulating the Antioxidant Defense System and Osmoregulation Substance Content in Gossypium hirsutum

“…About 7% of the total global land area is affected by the detrimental effects of salinity [4]. It has also been projected that 20% of the total cultivable land and 33% of the irrigated agricultural land are affected by salt, an area that increases at an alarming rate of 10% annually, equating to a 2.0% and 3.3% increase per annum, respectively [5,6]. In China, approximately 4.88% of the total available land is affected by salinity [7].…”

“…Apart from antioxidants, the plant also accumulates various osmolytes, such as sugar, proteins, amino acids, and glycine betaine, for metabolic modification to overcome salt-induced lethal effects. Organic osmolytes are deposited within vacuoles of the cytoplasm to maintain osmotic adjustment, protect cell membranes, and denature protein by retaining the cell turgor [6,22]. It has been reported that plants with an improved antioxidant defense system, stronger metabolism of organic osmolytes, and higher accumulation of essential mineral nutrients display better salt tolerance [23,24].The adaptation of plants to salt stress may result in several aspects that function at the ionic, morphological, physiological, biochemical, and genetic levels [25,26].…”

iTRAQ protein profile analysis of sugar beet under salt stress: different coping mechanisms in leaves and roots

“…Accumulation of SuSy under abiotic stress has been found in several plants, especially in roots [35][36][37] . SuSy is not only involved in osmotic regulation of plants, but also functions at a branch point to allocate sucrose to either cell wall biosynthesis or glycolysis [38] .…”

Histone Deacetylase Inhibitor SAHA Improves High Salinity Tolerance Associated with Hyperacetylation-Enhancing Expression of Ion Homeostasis-Related Genes in Cotton

“…Salinity stress is one of the most serious factors limiting plant growth and production. It has been estimated that more than 20% of irrigated land is suffering with high salinity, and the salinized land is becoming more widespread due to climate change and human input [ 1 ]. High concentrations of salts in the soil make it difficult for plants to take up water, and excessive salt intake can be toxic to plants, leading to failure in ion homeostasis and growth [ 2 ].…”

“…There are about 35 million ha of land for cotton fields, and 75% of cotton fields suffer from salt stress [ 32 ]. Therefore, high salinity stress is a serious threat to cotton growth and production, especially at germination and seedling stages [ 1 ]. Understanding the genetic and epigenetic mechanism of cotton response to salinity may assist in developing strategies for improvements in salt tolerance of cotton.…”