Plants’ Response Mechanisms to Salinity Stress

Abstract

Soil salinization is a severe abiotic stress that negatively affects plant growth and development, leading to physiological abnormalities and ultimately threatening global food security. The condition arises from excessive salt accumulation in the soil, primarily due to anthropogenic activities such as irrigation, improper land uses, and overfertilization. The presence of Na⁺, Cl−, and other related ions in the soil above normal levels can disrupt plant cellular functions and lead to alterations in essential metabolic processes such as seed germination and photosynthesis, causing severe damage to plant tissues and even plant death in the worst circumstances. To counteract the effects of salt stress, plants have developed various mechanisms, including modulating ion homeostasis, ion compartmentalization and export, and the biosynthesis of osmoprotectants. Recent advances in genomic and proteomic technologies have enabled the identification of genes and proteins involved in plant salt-tolerance mechanisms. This review provides a short overview of the impact of salinity stress on plants and the underlying mechanisms of salt-stress tolerance, particularly the functions of salt-stress-responsive genes associated with these mechanisms. This review aims at summarizing recent advances in our understanding of salt-stress tolerance mechanisms, providing the key background knowledge for improving crops’ salt tolerance, which could contribute to the yield and quality enhancement in major crops grown under saline conditions or in arid and semiarid regions of the world.

The Morphological Parameters and Cytosolic pH of Cells of Root Zones in Tobacco Plants (Nicotiana tabacum L.): Nonlinear Effects of NaCl Concentrations

“…Particularly, the osmotic component of salt stress predominantly influences the deceleration of seed germination by limiting water uptake and seed swelling [5]. The ionic component of salt stress is realized through the competition with other ions, primarily with K + , perturbation of protein functionality (particularly enzymes in the case of sodium), and metabolic transport alterations (in the case of chlorine), and the change in the intracellular pH [70][71][72][73]. This complex interplay inevitably influences the rate of cell division, cell expansion, and cell wall formation [56].…”

Putting Biochar in Action: A Black Gold for Efficient Mitigation of Salinity Stress in Plants. Review and Future Directions

“…32 The disturbed nutrient acquisition under saline conditions is linked with a reduction in nutrient availability owing to the competition of major ions (Ca 2+ , K + , and Mg 2+ ) with Na + and Cl − . 33 Nitrogen is an essential nutrient needed for plants, and an increase in Cl − uptake and accumulation under saline conditions can decrease the N uptake. 34 Salinity stress also negatively affects the phosphorus uptake and salinity-induced excessive Cl − reduces the P uptake, possibly owing to the high ionic strength of the media and low solubility of the Ca ± P minerals.…”

“…The disturbed nutrient acquisition under saline conditions is linked with a reduction in nutrient availability owing to the competition of major ions (Ca 2+ , K + , and Mg 2+ ) with Na + and Cl – . Nitrogen is an essential nutrient needed for plants, and an increase in Cl – uptake and accumulation under saline conditions can decrease the N uptake .…”

Vigna marina as a Potential Leguminous Cover Crop for High Salinity Soils

“…These factors include the inhibition of chlorophyll biosynthesis, produced by the activation of the chlorophyllase enzyme, as well as the destruction of cellular membranes due to chlorophyll breakdown mediated by salinity (Muhamad Hassan et al, 2022). The adverse effects of salt stress on plants are evident in their morphology, physiology, and biochemical properties: morphologically, plants experience stunted growth, chlorosis, and impaired seed germination; physiologically, salt stress inhibits photosynthesis and disrupts nutrient balance; biochemically, plants undergo oxidative stress, electrolyte leakage, and membrane disorganisation (Balasubramaniam et al, 2023). The decrease in photosynthesis under saline soils caused a reduction in chlorophyll content, as the chlorophyll index was shown to be reduced in sensitive genotypes under salt stress conditions, but it was observed to be raised in tolerant genotypes (Heidari, 2012;Masarmi et al, 2023).…”