s one of the most disturbing environmental stresses worldwide, salt stress has been projected to significantly increase due to the climate change
[1]][2]][3]3]. Excessive salt concentrations were reported in about 7% of the global land, whereas salt has affected almost 20% of the arable land and 33% of the irrigated land in the world
[4]4]. Additionally, by the year 2050, a continued exposure of arid and semi-arid regions to salt stress is predicted to cause about 30–50% losses worldwide
[5] [5; the salt-affected area is estimated to increase to 16.2 million ha
[6] [6. The increasing land area by salt stress urges plant scientists to build up strategies for sustainable crop production.
.The excessive salinity in the rhizospheric zones can negatively affect growth and productivity through creating an imbalance in the cytoplasmic ion homeostasis and thereby impacting metabolic dysfunction and other major biochemical and physiological processes
[3][7] [3,7. Varied reactive oxygen species (ROS) generated at higher level can occur due to salinity stress in plant cells, can act as signaling molecules, and help in mediating numerous key physiological processes
[8] [8. However, overproduced or non-metabolized ROS can be toxic to plants and cause oxidative damage to cellular constituents including macromolecules (DNA, lipid, and proteins), and, eventually, cause cell death
[9[][10]],10.
.Major mineral nutrients not only constitute a significant part of the agricultural system but also are widely known to modulate the synthesis and production of many plant hormones and thereby help in plant-adaptation to stresses including salt stress
[2][11] [2,11. Nitrogen (N) and sulfur (S), crucial mineral nutrients (macronutrients), are known to exhibit regulatory interactions and regulate plant growth and development
[12] [12. Notably, the synthesis of most amino acids and proteins, nucleic acids, and several other cellular components involves N
[13] [13. In many instances, N-assimilation and cellular ion homeostasis were reported to contribute in plant tolerance to salt stress
[14][15] [14,15. On the other hand, owing to its occurrence in various S-containing compounds, it serves as a key nutrient known to improve inherent capacity of plant for stress tolerance
[15][16] [15,16. Interestingly, most plant nutrients are interrelated with several phytohormones, where their synergistic or antagonistic actions contribute in modulation of the physiological/biochemical responses leading to salt tolerance
[2] [2.
.Nitric oxide (NO) is a gaseous phytohormone and a reactive nitrogen species (RNS). As a free radical gaseous signaling molecule, NO is involved in plant development and nutrient assimilatory processes and also improves plant tolerance to major stresses such as the soil salinity
[17][18][19][20] [17,18,19,20. Ethylene (ETH) is another gaseous phytohormone that influences plant responses to salt stress
[21][22] [21,22. Various studies have shown the interaction of NO and ETH with N and S under abiotic stress. Studies have reported the interactive effects of NO with N and S
[2] [2 and ETH with N and S
[10] [10. N-availability was reported to influence ETH -production and improve salt tolerance in mustard
[23] [23, whereas NO was found to enhance the photosynthetic nitrogen use efficiency (PNUE) and photosynthetic sulfur use efficiency (PSUE). Owing to the occurrence of a close link between the assimilation of N or S with salt stress tolerance, the identification and analyses are imperative to enlighten how much N or S assimilation is induced by phytohormones or vice-versa in order to counteract the salt stress-consequences in plants. The understanding of the role of NO and ETH in the regulation of assimilation of N or S may help in highlighting insights into the plant salt tolerance induced by N- or S-assimilation.
.Considering the above aspects, this paper: (i) overviews major salt stress-impacts in plants; (ii) appraises literature available on the role and coordination-outcomes of N and S in plant salt tolerance; (iii) presents discussion on the role of NO and ETH, and the significance of crosstalk of ETH and NO with N and S in plant salt tolerance; and (iv) enlightens so far unexplored aspects in the current context.
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