Abstract
Wheat constitutes pivotal position for ensuring food and nutritional security; however, rapidly rising soil and water salinity pose a serious threat to its production globally. Salinity stress negatively affects the growth and development of wheat leading to diminished grain yield and quality. Wheat plants utilize a range of physiological biochemical and molecular mechanisms to adapt under salinity stress at the cell, tissue as well as whole plant levels to optimize the growth, and yield by off-setting the adverse effects of saline environment. Recently, various adaptation and management strategies have been developed to reduce the deleterious effects of salinity stress to maximize the production and nutritional quality of wheat. This review emphasizes and synthesizes the deleterious effects of salinity stress on wheat yield and quality along with highlighting the adaptation and mitigation strategies for sustainable wheat production to ensure food security of skyrocketing population under changing climate.
Introduction
Recently, climate change and global warming have directly affected the crops yield and quality by intensifying the frequency and extent of numerous stresses. Wheat, rice, and maize are the most important staple crops globally and contribute a significant part of daily calories and protein intake (Kizilgeci et al., ). Among these major cereals, wheat is ranked at the first position due to its domestication and contribution as the primary staple food crop globally (Iqbal et al., ). Currently, it is dominating the most of arable land (38.8%), with relatively higher grain protein (12–15%) than other cereals, but the productivity remains low [Food and Agriculture Organization (FAO) of the United Nations, ]. It can further decrease owing to climate change that has given to rise a variety of abiotic stresses. Various climate models projected that wheat production could decrease by 6% due to stressful environments (Asseng et al., ).
Salt stress affects 20% of global cultivable land and is increasing continuously owing to the change in climate and anthropogenic activities (Arora, ). Environmental stress including salinity can cause about 50% of production losses (Acquaah, ). Furthermore, the continuous increase in the human population put pressure on global food security as the world's food supply needs to be increased by up to 70% by 2050 (FAO, ). Wheat (Triticum aestivum) is considered the most significant grain crop among all the cereals and ranked 1st globally among grain-producing crops, especially for human consumption (Giraldo et al., ). About 36% of the world's population is dependent on wheat as a staple food. About 20% of calories and 55% of carbohydrates are being provided by wheat across the globe. Both growth and yield of wheat are negatively influenced by salinity (Royo and Abió, 2003). Salinity stress causes osmotic stress and ion toxicity, through increasing the assimilation of Na+ ion and decreasing the Na+/K+ ratio due to lower osmotic potential within the plant roots. Further, these ionic imbalance affects the uptake, and transport of other important essential ions in target cells and hamper the crucial plant processes and functions (Arif et al., ). Salinity impairs the seedling establishment, stunted plant growth, poor reproductive development, and ultimately declines the crop yield (Turan et al., 2009). Salinity also alters the ultrastructural cell components, disturbs the photosynthesis machinery, damages the membranous structure, increases the reactive oxygen species production, reduces the enzymatic activity, which limit the growth and yield of crops (Hasanuzzaman et al., ). Tolerancey of plants to salinity is a polygenic character that is governed by many genetic factors (Arzani and Ashraf, ). Crop growth is improved under salinity by the increase in K+, elimination of Na+ or by optimizing the ratio of both Na+ and K+ ions, improving transpiration efficiency, regulation of osmotic potential, and by the antioxidant, immune system of plants (Rahman et al., 2005).
Among various field crops, generally, wheat is more sensitive to salinity that hampers the growth and development of plant, leads to low productivity or even complete crop failure under extreme severity of salinity. The knowledge of stress tolerance in plants regarding the physiological basis is important for selection and breeding programs (Chaves et al., ). Thus, understanding of morphoanatomical, physiological, biochemical, and molecular mechanisms of wheat responses to salinity stress at each phase of growth is essential to improve breeding techniques and to develop salt-tolerant varieties with genetic modifications. The recent findings indicate that change in leaf and stem anatomical features in different genotypes of wheat are crucial traits to adaptation under salinity stress (Nassar et al., ). The research on the physiological changes that occur during leaf senescence due to some stresses has been primarily focused on the loss of photosynthetic pigments, protein degradation, and re-absorption of mineral nutrients (Zheng et al., 2008). At the same time accumulation of secondary metabolites (anthocyanins, flavones, phenolics, and specific phenolic acids) often occurs in plants subjected to stresses including various elicitors or signal molecules (Sytar et al., 2018). It was demonstrated that pigmented wheat genotypes with high anthocyanin content can maintain significantly higher dry matter production under salt stress conditions (Mbarki et al., ), which shown the role of phenolic compounds in salinity tolerance together with new breaded pigmented wheat genotypes.
Determination of physiological traits related to stress tolerance could be used as a selection criterion to enhance wheat adaptation to stress conditions. According to the previous investigations, there is a link between different physiological responses of crops to stress and their tolerance mechanisms, such as high relative water content and water potential (Datta et al., ). Moreover, it has been observed that anthesis and grain filling period are very sensitive stages under multiple environmental stresses including salinity and have been identified as major constraints to wheat production worldwide (Ghosh et al., ). Therefore, it is crucial to understand the effects of salt stress on wheat yield improvement while maintaining superior productivity and adopting mitigation strategies toward the long-term goal of sustainable food security. This study aimed to synthesize salinity effects on wheat germination, seedling growth, reproductive development, grain yield, and quality. Additionally, deleterious effects of salinity in relations to nutrient imbalance and water relations have been objectively described. Moreover, integrated approach for salinity mitigation through osmoprotectants, plant hormones, mineral nutrients, and signaling molecules has been elucidated.
The current review overviews the adverse effects of salinity stress on wheat and its adaptation and mitigation strategies for the sustainability of wheat productivity under the changing climate.
Adverse Effects of Salinity Stress on Wheat
Most of the agricultural lands, which are affected by different degrees of salinity, are located in semi-arid or arid regions (Liu et al., ). Huang et al. () concluded that the damage of crops is mostly intensified by the synchronized action of xerothermic aspects, such as aridity and high temperature. Salinity is the most adversely affecting factor on productivity and quality of wheat through altering the physiological as well as biochemical activities in plants. Generation of ROS due to Na+ toxicity, which damage biomolecules (e.g., lipids, proteins, and nucleic acids) (Apel and Hirt, ) on the cellular level and alters redox homeostasis, is a common phenomenon under salt stress (Kundu et al., ). However, salt impacted soils are difficult to remediate due to the circumstances outlined by Arzani and Ashraf (). First, Na+ and Cl− ions are highly mobile in soils. Second, it is often an expensive and short-term solution for the chronic problem. Third, soil salinity has a dynamic nature and spatial variation in salinity is generated by the interactions among different variables of edaphic effects (soil pH, bulk density, permeability, topography, geohydrology, water table depth, and groundwater salt content), geographic factors (elevation, slope, and aspect), agronomic practices (irrigation, drainage, tillage, crop rotation, and fertilization), and climatic effects (temperature, humidity precipitation, wind, and evaporation) (Bui, ). Therefore, the integrated agronomical, physiological, and soil management approaches and targeting multiple traits at the same time are a crucial step to achieve salinity tolerance. Therefore, it is important to substitute Na+ with the Ca2+ followed by removal/leaching of salts derived by the reaction of the amendment from sodic soil for sustainable crop production (Sorour et al., 2019).
Salinity delays the onset of seedlings germination, decreases the seedling growth and the dispersion of germination events, seedling metabolism, causing a reduction in plant growth and crop productivity (El Sabagh et al., ,,, ). One important approach is to develop an understanding of the plant response toward salinity stress. The response of plants to salinity can be described in two subsequent phases (Arzani and Ashraf, ), during the first phase, salinity causes osmotic stress because of a decrease in the soil water potential (James et al., ). The second phase develops within a few days or weeks (depend on the severity of salinity) and accumulates Na+ ions in different plant tissues, causing reduced yield and even plant death (Munns and Tester, ). Under salinity, Na+ is the principle of toxic ion imposing both osmotic stress and ionic toxicity (Munns and Tester, ). Salinity also negatively affects wheat phenological developments such as leaf number, leaf expansion rate, and root/shoot ratio (El-Hendawy et al., ), and biomass production (Sorour et al., 2019). The saline environment disturbs plant water relations including relative water content, leaf water potential, water uptake, transpiration rate, water retention, and water use efficiency (Nishida et al., ).
Salinity adversely affects the growth and yield of crop plants by decreasing the availability of soil moisture, and due to the toxicity effects of sodium and chloride ions at high concentrations to the plant (Munns and Tester, ). Salinity stress accelerates all phenological phases of wheat (Grieve et al., ), reduces the number of fertile tillers (Abbas et al., ), decreases the number of spikelet number spike−1 (Frank et al., ), kernel weight (Abbas et al., ), and affects grain yield adversely (Sorour et al., 2019). For instance, yield losses up to 45% have been recorded in salt-stressed wheat (Ali et al., ). Hasan et al. () observed that saline stress (15 dSm−1) significantly decreases grains per spike, 1,000-grain weight, and seed yield in tolerant and sensitive wheat cultivars. The effect of salinity stress on root activity, germination, morphological traits, crucial plant processes, yield, and yield attributes in wheat are illustrated in Figure 1.
Figure 1
Germination and Plant Growth
Soil salinity is the second major factor responsible for land degradation after soil erosion, causing a decline in agricultural economic outputs for 10,000 years (Shahid et al., 2018). Poor salinity management can cause soil sodicity of farming soils, where sodium (Na) binds to negatively charged clay, causing clay swelling and dispersal, subsequently decreasing the crop yield. Higher levels of salinity confiscate 1.5 million hectares of land globally every year, and hence ~50% of cultivable land could be deteriorated by the mid of 21st century. During salinity, the exaggeration of most plants is apparent in the early stages, especially during seedling establishment, as it is the most responsive and critical stage that is reported to be strongly associated with successful germination and seedling development. Various factors hamper the crop yield under salinity stress, but osmotic stress, ionic imbalance, and oxidative stress are the major ones among them. In brief, the osmotic stress leads to a higher accumulation of salts in cell sap and tissues which become observable as leaf burn and wilting. These symptoms are reported to be associated directly with the accumulation of Na+ and Cl−. Thus, this ionic imbalance causes disequilibrium of nutrients that declines germination, and adversely affects the subsequent metabolic processes (Hussain et al., ). Furthermore, the oxidative stress exerted via accelerated ROS generation induces lipid peroxidation, disrupt nucleic acids that ultimately decreases the consistency and overall yield of the affected seed (Dehnavi et al., ; Kumari and Kaur, ).
Germination is a dynamic and critical phase in the lifecycle of a plant that pledges via the imbibition of water (Kumari and Kaur, ). It is a triphasic process, and during phase 1, the seeds absorb water, followed by the second phase, i.e., the “plateau phase” (stable water content), and characterized by test rupturing. In the third phase, endosperm ruptures and radicle protrusion take place, and it is also referred to as the post-germination phase (Chamorro et al., ). In 2007, Läuchli and Grattan proposed a general scheme for depicting the relationship of germination percentage with the time of germination under low, moderate, and high salinity levels (Figure 2).
Figure 2
Salinity inhibits seed germination by either exerting osmotic stress that thwarts water uptake or causes ionic toxicity. These consequences collectively inhibit cell division and expansion, as well as modulates the activity of some key enzymes, thus lastly reduces the seed reserves utilization (El-Hendawy et al.,
Adverse Effects of Salinity Stress on Morphological Processes of Plants
Soil salinity detrimentally affects the various morphological characteristics of wheat plants including seedling growth, plant height, shoot, and root length, the number of roots, leaves, leaf area, fresh and dry weight, root/shoot ratio, and chlorophyll content. Ahmad et al. (
Adverse Effects of Salinity Stress at the Reproductive Stage on Plant Growth and Yield
Several earlier studies illustrated that the reproductive phase of any crop is the most sensitive stage to the abiotic stresses, including salinity (Ehtaiwesh and Rashed,
Besides ionic imbalance, salinity stress influences available soil water, tissue water content, water use efficiency, water potential, transpiration rate, rooting depth, root respiration, root biomass, root hydraulic conductance, cell turgidity, and osmolytes accumulations (Zheng et al., 2008). Besides, it also reduces the photosynthetic rate, biomass accumulation, and source-sink activity, which hastens the reproductive organ's senescence and negatively affects the yield response factors (Khataar et al.,
Although, Ashraf and Ashraf (
In spite of these changes, salinity stress has substantial impacts on grain quality traits. For example, the use of 200 mM of NaCl in wheat (cv. Shatabdi) showed an increase in Na+, K+, and Ca+2 content in grains by 155, 10, and 20%, respectively under stress (Tareq et al., 2011). Similarly, the use 0.75% NaCl salt increased the contents of high molecular weight glutenin subunit, glutenin macro-polymers (36.14%), and amino acids and improved wheat quality at certain levels but reduce grain yield (Zhang et al., 2016). Similarly, Nadeem et al. (
Adverse Effects of Salinity on Grain Quality
Soil salinity imparts detrimental impacts on vital metabolic, biochemical, and physiological processes occurring within the plants leading to the deterioration of grain quality. The extent of changes in grain quality caused by salinity depends on the sternness of the stress. From physiological perspectives, grain quality is affected owing to the accumulation of salts in the root zone leading to osmotic stress induction, which vigorously disrupted cell ion homeostasis. Salt exposure causes osmotic stress at the beginning, while subsequently, ion toxicity hampers growth, grain development, and quality, especially if the exposure periods get prolonged. The deterioration of grain quality of cereals has also been explained in agronomic perspectives as well. The reduction in the capability of roots for water uptake owing to osmotic stress contributes to growth inhibition, declined crop productivity, and inferior grain quality (Netondo et al.,
Winter wheat constitutes a vital source of carbohydrates and protein for humans across the globe (Siddiqui et al., 2019). There have been significant achievements pertaining to boost wheat yield over the decades. However, the demand for higher-quality grain has also increased with the improvement in human lifestyle (Park et al., 2009). Plant variety, in conjunction with the prevalent environment, has also been reported to determine the wheat quality to a certain extent (Sairam et al., 2002). Previously, most researchers focused on the impacts of salinity on wheat grain yield (Zheng et al., 2009), but little is known about the relationships between salt-tolerance and grain quality. There are diverse effects of salinity levels on the grain quality of cereals. It has been inferred that salinity levels, especially beyond 150 mM of NaCl, significantly reduced the grain yield, whereby grain quality deterioration remained significant at 100 mM (Farooq and Azam,
As far as grain quality of cereals under abiotic stresses especially salinity is concerned, there have been relatively limited investigations. Protein, fat, and fibers contents in grain decreased significantly due to salinity. In response to imposed salinity, protein content improved in the sensitive wheat genotypes, while it decreased in tolerant genotypes. The ash and beta-carotene contents were enhanced, while the gluten index got declined considerably (Katerji et al.,
Protein Content
Protein content is the most important indicator of wheat grain quality and hence it governs and determines the end-use quality. The grain quality of wheat, especially the quality of protein as well as its quantity, is vital for dough properties and the bread-making quality of wheat flour. Under the saline condition, the protein quantity is increased, but the protein quality is decreased in wheat and triticale. The protein content is controlled by the genetic makeup of a particular cultivar or line, environmental factors, especially temperature and soil fertility status predominantly concerning N concentration in soil solution. It is significantly affected by environmental factors and their interactions. Positive correlations between environmental factors and wheat grain protein content have been reported during grain filling (Huebner et al.,
Gluten Content
The proteins for gluten storage are divided into gliadins (confers extensibility) and glutenins (causes elasticity). Similar to the protein content of the wheat grain, salinity tends to boost wet and dry gluten content in salt-tolerant wheat cultivars, while the opposite has been observed for salt-sensitive cultivars (Khan et al.,
Ash Content
The Ash content of wheat grain represents the mineral constituents of grain. In comparison to saline conditions, optimal growing conditions give rise to the higher ash content of whole-grain owing to improved minerals uptake from the soil solution (Troccoli et al., 2000). Contrarily, Katerji et al. (
Carbohydrate Content
Carbohydrate content is an important indicator of wheat grain quality, which is influenced by salinity stress, especially when wheat plants are exposed to saline environment at the grain filling stage. The synthesis and translocation of carbohydrates are more sensitive to suboptimal growing conditions compared to protein production (Rao et al., 1993). Salinity stress at the post-anthesis stage seriously shortens the accumulation duration of storage proteins leading to modification in gliadins and glutenins accumulation pathways. Moreover, the disruption effects of salinity on photosynthesis rate reduces carbohydrates synthesis at the vegetative growth stage, while it also disrupts or halts the translocation of carbohydrates toward grains at the initiation of grain filling stage, and thus it results in a significant reduction of carbohydrates concentration in wheat grain (Fernandez-Figares et al.,
Beta-Carotene Content
There are rare research investigations that have focused on wheat grain quality, especially beta-carotene content under salinity stress. The beta-carotene contents varied significantly in salt-tolerant and sensitive cultivars of durum wheat under saline conditions. The beta-carotene content of grains recorded a sharp decline in wheat cultivars under salt stress environments (Katerji et al.,
Salinity and Nutrient Imbalance
One of the adverse effects of a saline environment, especially high salt concentration in soil solution, causes a severe reduction in the uptake of nutrients and water. Resultantly, osmotic stress intensifies ion toxicity, imbalance of nutrients under water-deficit conditions. Salinity leads to injury of photo-synthetically active leaves by causing chlorosis and triggering leaf senescence in cereals (Hanin et al.,
Inorganic ions often perform to be competitive enzyme inhibitors, which host ionic substrates but also interfere with protein surface charges besides destabilizing molecular level interactions. The nutrient imbalance under saline conditions leads Na+ to substitute K+ from the essential binding sites. In biochemistry, the typical instances for K+ dependency are ribosomes and pyruvate kinase. It has been reported that K+ presence in optimal concentration boosts pyruvate kinase activity (Vmax) as much as 400 times (Oria-Hernández et al., 2005), while K+ substitution by Na+ causes inhibition up to 92%. In addition, peptidyl transferase activity in eukaryotic ribosomes gets regulated by K+ concentration and might reach upto 20 s−1 under optimal conditions (Ioannou and Coutsogeorgopoulos,
Under normalized conditions, nutrient ion net fluxes of different cereals (maize, wheat, and barley) and legumes such as broad beans get adjusted in accordance with cellular requirements and crop development phases, leading to the establishment of ionic homeostasis (Niu et al.,
Under NaCl salinity, it seems that Cl− tends to hinder the growth and development of crops by inducing the deficiency of phosphorous and sulfur through inhibiting PO43− and SO42− uptake. However, facts remain that generalizable conclusions may not be drawn from the published research and relevant findings. For concise conclusiveness, it becomes pertinent to distinguish between Cl− and counter-cations effect under saline environment. There is a dire need to perform further experiments regarding the behavior of membrane-impermeable counter-cations of a specific salt. Besides, the underlying molecular mechanism of nutrient-nutrient antagonistic uptake remains unclear. However, one of the possible justifications can be attributed to antagonistic competition for a binding site at transport proteins of salts ions. Another justification can be leaking of Cl− from protein pores, which quantitatively displace PO43− or SO42− leading to a sharp decline in their take up. Both above-stated scenarios rely on transmembrane pores, physicochemical attributes such as their charge and size. For instance, hydrated Cl− ion radius is similar to SO42−. It seems that under salinity stress, glycophytic crops did not encounter the necessity to escape Na+ and Cl− uptake during the breeding and evolution process, which hampered the development of adaptive mechanism at the transporter site for differentiating among the requisite nutrients and undesired ions of salts. Thus, it might be inferred that two pronged strategy encompassing reduction in the uptake of salt ions and their replacement in the soil solution as well as plant need further investigations to cope with the serious challenge of salinity and impart sustainability to cereals production.
Water Relation to Salinity Stress
Wheat plants exposed to salt stress change their environmental condition. The capability of plants to tolerate salt is determined by several biochemical ways that facilitate the acquisition or maintenance of water relations, ionic homeostasis, and protect chloroplast functioning. In agriculture, salinity has been the most distressing abiotic stress having pronounced damaging effect on physiological, morphological, and biochemical characteristics of the crop plants, including uptake of water and nutrients, germination, growth, photosynthesis, enzyme actions, and yield (Cisse et al.,
Accessibility of water in plants is a crucial factor for all physiological and metabolic processes of plants (Sreenivasulu et al., 2007). The higher concentration of salts causes osmotic stress to plants, which results in low water potential in wheat crop (Qamar et al., 2020). The rate at which new leaves are produced depends basically on the water potential of the soil water, in the same way as for a drought-stressed plant. According to the previous investigations, there is a link between the different physiological reaction of crops to stress and their tolerance mechanisms, viz. high relative water content and water potential (Datta et al.,
Water potential of plants at reproductive phases also reduces the cell extension, vascular tissue thickness, flag leaf thickness, mesophyll, and epidermal cell size, which are responsible for the reduction of flag leaf turgidity, flag leaf area, assimilates synthesis, and yield potential (Nassar et al.,
Consequently, from these findings, we conclude that salinity stress is a major factor for limiting yield and grain quality traits, and it affects the reproductive phase severely by altering ionic homeostasis, water status, and assimilate partitioning. Foliar application of antioxidants and growth regulators that maintain an appropriate water level in the leaves to facilitate adjustment of osmotic and stomatal activity (Arshad et al.,
Approaches to Improve Salt Stress Tolerance in Wheat
Improving the crop performance by conventional breeding methods, introducing gene markers, and selection of genetically modified genotypes are the basic approaches to produce tolerance against salinity stress in plants (Hasanuzzaman et al.,
Table 1
| Transgene | Name | Source | Mechanism | References |
|---|---|---|---|---|
| mtld | Mannitol | Escherichia coli | Improved shoot fresh weight, dry weight, plant height, and flag leaf length by 27, 43, 13, and 16% respectively | Abebe et al., |
| P5CS | Proline | Vigna aconitifolia | Enhance proline content 2.5-fold (1,320–7,600 μg g−1) as compared to control (110–2,800 μg g−1) under salt stress | Sawahel and Hassan, 2002 |
| betA | Choline dehydrogenase | Escherichia coli | Enhance glycine betaine content 1.4–2.8-fold, accumulate more K+, improve root and shoot biomass (34 and 33% respectively), 62–76% more proline accumulation and yield 151–190% higher as compared to wild type | He et al., |
| HvBADH1 | Glycine betaine (GB) | Hordeum vulgare | Increase K+ ion in cytosol, Induce accumulation of GB 11.59–21.82-fold, 26.2–29.1 higher survival rate | Li et al., |
| AtNHX1 | Na+/H+ antiporter gene | Arabidopsis thaliana | Improve root, shoot length and fresh weight significantly under saline conditions, and 3-fold enhance in K+/Na+ ratio (0.55–1.66) | Xue et al., 2004 |
| TdPIP2;1 | Aquaporin | Triticum turgidum L. subsp. durum | Improve germination percent, root and shoot length, transpiration efficiency, decreased Na+/K+ ratio by 3.9–2.85, and antioxidant enzymes | Ayadi et al., |
| AISAP | Stress associated protein | Aeluropus littoralis | Reduced root elongation 12 and 18% as compared to wild type 75 and 78% under salinity and osmotic stress, improve leaf water content 2-fold, improve test weight, and higher sequestration of (80%) Na+ as compared to wild type (58%) | Ben-Saad et al., |
| EdVP1 | V-type H+-pyrophosphatase | Elymus dahurica | Improve K utilization efficiency, K influx, affect the activity of K transporter in the plasma membrane, distribution of auxin, chlorophyll content, biomass, and yield attributes | Zhou et al., 2020 |
| TaBASS2 | Pyruvate transporter | Wheat cultivar Shanrong 3 | Improve relative root and shoot growth, reduce oxidative stress, lower Na+ contents | Zhao et al., 2016 |
Highlights the some transgenic developed in wheat crop and influenced traits for salinity tolerance.
Salt Tolerance Through Osmoprotectants
Various mechanisms are adopted by plants under salinity stress at the organism and tissue level to avoid adverse effects of salinity. Plants produce osmolytes and some beneficial solutes that prevent them from the impact of salinity stress by maintaining osmotic and ionic balance (Ashraf and Foolad,
Salinity Tolerance Through Plant Hormones
Salt stress tolerance and plant growth regulation are associated with the biosynthesis of a variety of compounds in minute concentrations, which are termed asplant hormones (Ryu and Cho, 2015). Salt stress was mitigated by several types of plant growth hormones, abscisic acid (ABA), auxins (AUX), cytokinin (CK), and ethylene (ET). Auxin is an important growth regulator that enhances seedling establishment, shoot dry weight, and also balanced the ionic pressure in plants under salinity stress (Iqbal and Ashraf,
Plant Nutrients
The availability of nutrients is also responsible for mitigating the salt stress effect by various physiochemical and biological mechanisms. Foliar application of potassium improves photosynthesizing efficiency, antioxidant enzymatic efficiency, potassium intake by plants, and sodium absorption and salt stress environments (El-Lethy et al.,
Salt Tolerance Through Various Signaling Molecules
Various signaling molecules can crosstalk with phytohormones and antioxidants within the plants that help plants to survive under salt stress. Nitric oxide (NO) is the most widely used signaling molecule to mitigate various abiotic stresses, particularly salt stress. It has interaction with other molecules by several pathways due to its signaling role besides improved crop productivity under salt-stressed environments (Hasanuzzaman et al.,
Use of Plant Growth Hormones in Mitigating Salinity-Induced Damages
Salt stress adversely affects plant growth and related metabolites, and consequently reduces crop yield (Islam et al.,
Gibberellic Acid (GA3)
Gibberellic acid improved the growth criteria, photosynthetic pigments, and consequently the crop yield of wheat cultivars due to better osmoregulation resulting in increased water flow and water status using the organic solutes (saccharides and proteins), which in turn increased the photosynthetic area and yield (Shaddad et al., 2013). Under saline stress conditions, GA3 stimulated the growth of wheat (Afzal et al.,
Abscisic Acid (ABA)
Abscisic acid has been found to be the main regulator of abiotic stress tolerance in wheat via regulation of protein kinases activities, which is important for phosphorylation processes (Umezawa et al., 2009). The contribution of Snf1-related protein kinases (SnRKs) has been studied extensively in Arabidopsis. Some studies of SnRKs in wheat has shown the presence of other SnRK2 homologs that appear to play a role in ABA-mediated abiotic stress signaling (Mao et al.,
Auxin and Cytokinin
The exogenous application of auxins, cytokinins mitigate the adverse effects of salt stress and consequently improved seed germination and growth (Naidu,
Salicylic Acid
The application of salicylic acid (SA) mitigates the harmful effect of abiotic stresses (Abhinandan et al.,
Ethylene
The promotion of abiotic stress tolerance in wheat has been shown by ethylene inhibitors (Abhinandan et al.,
The activation and expression of some ethylene-responsive factors, proteins like TaERF1 and TaERF3, which support resistance to multiple stresses, can be induced by the perception of abscisic acid or ethylene (Rong et al., 2014). The study with isolation and molecular characterization of TdERF1, an ERF gene from durum wheat (Triticum turgidum L. subsp. durum) different varieties showed that TdERF1 gene may provide a discriminating marker between tolerant and sensitive wheat varieties (Makhloufi et al.,
Salt stress declines the metabolic activity of plant cells, which inevitably reflects the inhibition of plant growth (Çiçek and Çakirlar,
Brassinosteroids (BRs)
The application of brassinosteroids (BRs) exogenously increases plant tolerance against abiotic stress (Abhinandan et al.,
Plant Growth-Promoting Bacteria (PGPB)
Plant growth-promoting bacteria directly or indirectly enhanced the growth of plants (Ahmad et al.,
The cross talks of signaling molecules with other PGRs compounds in wheat crop under salinity are highlighted in Table 2. In this table different signaling molecules and PGRs are participating in common signaling pathways and regulates the multiple stresses tolerance.
Table 2
| Crosstalk | Mechanism of salinity tolerance | Trait influenced | References |
|---|---|---|---|
| NO-CaNO3 | Increase Ca+2/Na+ ratio, synergistically improve ion homeostasis | Improved fresh and dry weight of root and shoot, leaf chlorophyll content, enhance root and H+-ATPase activity, antioxidant defense | Tian et al., 2015 |
| Methyl jamonate (MJ)- cytokinin | Modulates cytokinin oxidase (CKX) activity and expression | Improved seedling biomass, mitotic index, and reduce electrolyte leakage by 7.9% | Avalbaev et al., |
| IAA+ GA3 | Neglected the negative effects of accumulated ethylene | Improve ion homeostasis by enhance essential mineral transport to target organ, induce the production of soluble sugar, protein, organic acid, and proline | Abd El-Samad, |
| IBA+ SNP | Synergistic effect and improved antioxidant defense | Improve carotenoid, total phenol, and catalase, activity | Mohsenzadeh and Zohrabi, |
| NO-H2S | Activate defense system and maintain normal cell machinery functions | Improve relative water content and reduce electrolyte leakage, sustain membrane integrity, improve proline and glycine betaine content, improved APX, CAT, POX, SOD, and GR activity | Khan et al., |
| Kinetin+ GA | Improved pigment composition and osmotic adjustment | Improved root and shoot dry weight, chlorophyll content, salt tolerance index, and accumulation of carbohydrate, lipid, and protein | Al-Mishhadani et al., |
| BR-MJ-Salicylic acid | Enhance the protective action by influencing hormonal homeostasis | Reduce ABA accumulation, maintain CK concentration, enhance the level of antioxidants and osmoprotectants, and enhance the expression of stress protein such as DEHYDRIN | Shakirova et al., 2012 |
| Melatonin-Polyamine | Regulate polyamine metabolism | 36 % improvement in seedling weight, improve efficiency of photosystem II, reducing H2O2 content, and induce endogenous melatonin and polyamine synthesis | Ke et al., |
| Ca+2-ABA | Regulation of ABA biosynthesis | Reduced the transcriptional levels of TabZIP8, 9, 13, and TaNCED1, 2 genes | Zhang et al., 2020 |
Highlights the crosstalk between plant growth regulators and signaling compounds to ameliorate the salinity stress in wheat crop.
Antioxidant Defense in Response to Salinity-Induced Oxidative Stress
Salinity stress hampers the antioxidant strength via altering antioxidant enzyme activity viz. biosynthesis of ascorbate peroxidase (APX), sodium dismutase (SOD), and glutathione reductase (GR), and non-enzyme antioxidant (ascorbic acid, glycine betaine, and proline). These changes in antioxidants cause the accumulation of harmful ROS, malondialdehyde (MDA), and elevation of lipid peroxidation, ion leakage, membrane stability, and ultimately weakening of antioxidant system (Sairam et al., 2002).
Oxidative stress is caused by production and accumulation of ROS in cells and tissues owing to irregularities in the electron transport chain (ETC) that cause lipid peroxidation, protein oxidation, nucleic acid damage, enzyme inhibition, activation of programmed cell death pathway, and ultimately causing cell death (Hossain et al.,
Several antioxidants have been exploited in recent years, which have a beneficial effect against oxidative stress, and to avoid oxidative damage higher plants usually raise the concentration of the endogenous antioxidant system comprising of enzymatic and non-enzymatic components to scavenge ROS (Sharma et al., 2012). In-plant cells, specific ROS producing, and scavenging systems have been established in different organelles viz., mitochondria, chloroplast, and peroxisomes etc. The enzymatic components of the antioxidative defense system (ADS) are comprised of several antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), guaiacol peroxidase (GPX), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) (Hossain et al.,
Figure 3

Illustrate the integrated approaches (physiological, biochemical and molecular) of salinity stress tolerance in wheat crop.
Conclusions
Among abiotic stresses, salinity stress especially in the arid and semi-arid regions of the world is one of has emerged as one of the most important threats to the sustainability of wheat production. It reduces germination, seedling growth as well as reproductive growth by disrupting numerous vital physiological and metabolic processes which lead to sharp decline in yield and quality depending on frequency and extent of saline environment. Although salinity tolerant plants employ several physiological and biochemical mechanisms to adapt under salinity stress, there is a lack of robust salinity tolerant wheat cultivars globally. Therefore, plant physiologists, breeders, and agronomists need to develop an integrated and sustainable strategy to enhance salt tolerance in wheat. Among these mitigation strategies, soil management practices, crop establishment, as well as the foliar application of antioxidants and growth regulators through maintaining an appropriate water level in the leaves to facilitate adjustment of osmotic and stomatal performance could be explored further to mitigate the adverse effect of salinity on wheat yield and grain quality. However, breeding strategies especially gene pyramiding should be undertaken to develop salt-tolerant varieties by exploring halotolerant gene homologs from wheat germplasm. However, an integrated approach involving soil and agronomic practices (drainage system management, salt leaching, nutrients managements for salt ions replacement), physiological strategies (osmotic adjustment, seed priming, improve photosynthesis efficiency, and water relation), biochemical (redox, ion, and hormonal homeostasis), and molecular tools (development of transgenic, genetic engineering, identification of gene, genes insertion, editing, or slicing) needs to be developed to ameliorate salinity effects and boost cereal production on sustainable basis.
Statements
Author contributions
All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
References
1
AbbasG.SaqibM.RafiqueQur-Rahman, M. A.AkhtarJ.ul- HaqM. A.NasimM. (2013). Effect of salinity on grain yield and grain quality of wheat (Triticum aestivum L.). Pakistan J. Agric. Res.. 50, 185–189.
2
Abd El-SamadH. M. (2013). The physiological response of wheat plants to exogenous application of gibberellic acid (GA3) or indole-3-acetic acid (IAA) with endogenous ethylene under salt stress conditions. Int. J. Plant Physiol. Biochem.5, 58–64. 10.5897/IJPPB12.016
3
AbdelgadirE. M.OkaM.FujiyamaH. (2005). Characteristics of nitrate uptake by plants under salinity. J. Plant Nutr.28, 33–46. 10.1081/PLN-200042156
4
AbebeT.GuenziA. C.MartinB.CushmanJ. C. (2003). Tolerance of mannitol-accumulating transgenic wheat to water stress and salinity. Plant Physiol.131, 1748–1755. 10.1104/pp.102.003616
5
AbhinandanK.SkoriL.StanicM.HickersonN.JamshedM.SamuelM. A. (2018). Abiotic stress signaling in wheat–an inclusive overview of hormonal interactions during abiotic stress responses in wheat. Front. Plant Sci. 9:734. 10.3389/fpls.2018.00734
6
AbidM.ShaoY.LiuS.WangF.GaoJ.JiangD. (2017). Pre-drought priming sustains grain development under post-anthesis drought stress by regulating the growth hormones in winter wheat (Triticum aestivum L.). Planta246, 509–524. 10.1007/s00425-017-2698-4
7
AcquaahG. (2007). Principles of Plant Genetics and Breeding. 2nd Edn. Oxford: Blackwell, 740.
8
AfzalI.BasraS. A.IqbalA. (2005). The effects of seed soaking with plant growth regulators on seedling vigor of wheat under salinity stress. J. Stress Physiol. Biochem.1, 6–14.
9
AfzalI.BasraS. M.FarooqM.NawazA. (2006). Alleviation of salinity stress in spring wheat by hormonal priming with ABA, salicylic acid and ascorbic acid. Int. J. Agric. Biol.8, 23–28.
10
AgarwalS.SairamR. K.SrivastavaG. C.MeenaR. C. (2005a). Changes in antioxidant enzymes activity and oxidative stress by abscisic acid and salicylic acid in wheat genotypes. Biol. Plant.49, 541–550. 10.1007/s10535-005-0048-z
11
AgarwalS.SairamR. K.SrivastavaG. C.TyagiA.MeenaR. C. (2005b). Role of ABA, salicylic acid, calcium and hydrogen peroxide on antioxidant enzymes induction in wheat seedlings. Plant Sci.169, 559–570. 10.1016/j.plantsci.2005.05.004
12
AhmadM.ShahzadA.IqbalM.AsifM.HiraniA. H. (2013a). Morphological and molecular genetic variation in wheat for salinity tolerance at germination and early seedling stage. Austral. J. Crop Sci.7:66.
13
AhmadM.ZahirZ. A.NazliF.AkramF.ArshadM.KhalidM. (2013b). Effectiveness of halo-tolerant, auxin producing Pseudomonas and Rhizobium strains to improve osmotic stress tolerance in mung bean (Vigna radiata L.). Brazil. J. Microbiol.44, 1341–1348. 10.1590/S1517-83822013000400045
14
AlamM. M.NaharK.HasanuzzamanM.FujitaM. (2014). Trehalose-induced drought stress tolerance: a comparative study among different Brassica species. Plant Omics7:271.
15
AliA.BasraS. M. A.AhmadR.WahidA. (2009). Optimizing silicon application to improve salinity tolerance in wheat. Soil Environ.28, 136–144.
16
AllaM. N.BadranE.MohammedF. (2019). Exogenous trehalose alleviates the adverse effects of salinity stress in wheat. Turkish J. Bot.43, 48–57. 10.3906/bot-1803-36
17
Al-MishhadaniI. I.IsmailE. N.JaddoaK. A.MajeedD. M.MohammedO. A. (2015). Estimation of the interaction effect between salinity and growth regulators on salt tolerance of two bread wheat cultivars. Int. J. Appl. Agric. Sci.1, 95–101. 10.11648/j.ijaas.20150104.12
18
AlzahraniF. O. (2021). Metabolic engineering of osmoprotectants to elucidate the mechanism (s) of salt stress tolerance in crop plants. Planta253, 1–17. 10.1007/s00425-020-03550-8
19
AmirbakhtiarN.IsmailiA.GhaffariM. R.Nazarian FirouzabadiF.ShobbarZ. S. (2019). Transcriptome response of roots to salt stress in a salinity-tolerant bread wheat cultivar. PLoS ONE14:e0213305. 10.1371/journal.pone.0213305
20
AmramA.Fadida-MyersA.GolanG.NashefK.Ben-DavidR.PelegZ. (2015). Effect of GA-sensitivity on wheat early vigor and yield components under deep sowing. Front. Plant Sci.6:487. 10.3389/fpls.2015.00487
21
ApelK.HirtH. (2004). Reactive oxygen species: metabolism, oxidative stress, and signal transduction. Annu. Rev. Plant Biol.55, 373–399. 10.1146/annurev.arplant.55.031903.141701
22
ArifY.SinghP.SiddiquiH.BajguzA.HayatS. (2020). Salinity induced physiological and biochemical changes in plants: an omic approach towards salt stress tolerance. Plant Physiol. Biochem.156, 64–77. 10.1016/j.plaphy.2020.08.042
23
AroraN. K. (2019). Impact of climate change on agriculture production and its sustainable solutions. Environ. Sustain.2, 95–96. 10.1007/s42398-019-00078-w
24
ArshadA.QamarH.Siti-SundariR.ZhangY.ZubairM.RazaM. A.et al. (2020). Phenotypic plasticity of spineless safflower (Carthamus tinctorius L.) cultivars in response to exogenous application of salicylic acid under rainfed climate conditions. Pakistan J. Agric. Res.33, 729–743. 10.17582/journal.pjar/2020/33.4.729.743
25
ArzaniA.AshrafM. (2016). Smart engineering of genetic resources for enhanced salinity tolerance in crop plants. Critic. Rev. Plant Sci.35, 146–189. 10.1080/07352689.2016.1245056
26
AshrafM.FooladM. R. (2007). Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environ. Exp. Bot.59, 206–216. 10.1016/j.envexpbot.2005.12.006
27
AshrafM. A.AshrafM. (2016). Growth stage-based modulation in physiological and biochemical attributes of two genetically diverse wheat (Triticum aestivum L.) cultivars grown in salinized hydroponic culture. Environ. Sci. Pollut. Res.23, 6227–6243. 10.1007/s11356-015-5840-5
28
AssengS.EwertF.MartreP.RötterR. P.LobellD. B.CammaranoD.et al. (2015). Rising temperatures reduce global wheat production. Nat. Clim. Change5, 143–147. 10.1038/nclimate2470
29
AvalbaevA.YuldashevR.FedorovaK.SomovK.VysotskayaL.AllagulovaC.et al. (2016). Exogenous methyl jasmonate regulates cytokinin content by modulating cytokinin oxidase activity in wheat seedlings under salinity. J. Plant Physiol.191, 101–110. 10.1016/j.jplph.2015.11.013
30
AyadiM.BriniF.MasmoudiK. (2019). Overexpression of a wheat aquaporin gene, TdPIP2; 1, enhances salt and drought tolerance in transgenic durum wheat cv. maali. Int. J. Mol. Sci.20:2389. 10.3390/ijms20102389
31
AzoozM. M.ShaddadM. A.Abdel-LatefA. A. (2004). Leaf growth and K+/Na+ ratio as an indication of the salt tolerance of three sorghum cultivars grown under salinity stress and IAA treatment. Acta Agron. Hungarica52, 287–296. 10.1556/AAgr.52.2004.3.10
32
BacilioM.RodriguezH.MorenoM.HernandezJ. P.BashanY. (2004). Mitigation of salt stress in wheat seedlings by a gfp-tagged Azospirillum lipoferum. Biol. Fert. Soils40, 188–193. 10.1007/s00374-004-0757-z
33
BarutcularC.YildirimM.KocM.Akinc,iC.TanrikuluA.El SabaghA.et al. (2016b). Quality traits performance of bread wheat genotypes under drought and heat stress conditions. Fresenius Environ. Bull.25, 6159–6165.
34
BarutcularC.YildirimM.KocM.AkinciC.ToptaşI.AlbayrakO.et al. (2016a). Evaluation of SPAD chlorophyll in spring wheat genotypes under different environments. Fresenius Environ. Bull.25, 1258–1266.
35
Ben-SaadR.Ben-RamdhanW.ZouariN.AzazaJ.MieuletD.GuiderdoniE.et al. (2012). Marker-free transgenic durum wheat cv. Karim expressing the AlSAP gene exhibits a high level of tolerance to salinity and dehydration stresses. Mol. Breeding30, 521–533. 10.1007/s11032-011-9641-3
36
BhuyanM. B.HasanuzzamanM.ParvinK.MohsinS. M.Al MahmudJ.NaharK.et al. (2020). Nitric oxide and hydrogen sulfide: two intimate collaborators regulating plant defense against abiotic stress. Plant Growth Regul.90, 409–424. 10.1007/s10725-020-00594-4
37
BielachA.HrtyanM.TognettiV. B. (2017). Plants under stress: Involvement of auxin and cytokinin. Int. J. Mol. Sci.18:1427. 10.3390/ijms18071427
38
BlumwaldE.AharonG. S.ApseM. P. (2000). Sodium transport in plant cells. Biochim. Biophys. Acta1465, 140–151. 10.1016/S0005-2736(00)00135-8
39
BorggaardO. K. (1984). Influence of iron oxides on the non-specific anion (chloride) adsorption by soil. J. Soil Sci.35, 71–78. 10.1111/j.1365-2389.1984.tb00261.x
40
BranlardG.DardevetM.SaccomanoR.LagoutteF.GourdonJ. (2001). Genetic diversity of wheat storage proteins and bread wheat quality. Euphytica119, 59–67. 10.1007/978-94-017-3674-9_18
41
BuiE. N. (2013). Soil salinity: a neglected factor in plant ecology and biogeography. J. Arid Environ.92, 14–25. 10.1016/j.jaridenv.2012.12.014
42
ChamorroD.LunaB.OurcivalJ. M.Kavgac,iA.SircaC.MouillotF.et al. (2017). Germination sensitivity to water stress in four shrubby species across the Mediterranean Basin. Plant Biol.19, 23–31. 10.1111/plb.12450
43
ChavesM. M.MarocoJ. P.PereiraJ. S. (2003). Understanding plant responses to drought-from genes to the whole plant. Funct. Plant Biol.30, 239–26410.1071/FP02076
44
ChenH.JiangJ. G. (2010). Osmotic adjustment and plant adaptation to environmental changes related to drought and salinity. Environ. Rev.18, 309–319. 10.1139/A10-014
45
ÇiçekN.ÇakirlarH. (2002). The effect of salinity on some physiological parameters in two maize cultivars. Bulgarian J. Plant Physiol.28, 66–74.
46
CisseA.ArshadA.WangX.YattaraF.HuY. (2019). Contrasting impacts of long-term application of biofertilizers and organic manure on grain yield of winter wheat in North China Plain. Agronomy9:312. 10.3390/agronomy9060312
47
DadshaniS.SharmaR. C.BaumM.OgbonnayaF. C.LéonJ.BallvoraA. (2019). Multi-dimensional evaluation of response to salt stress in wheat. PLoS ONE14:e0222659. 10.1371/journal.pone.0222659
48
DarveyN. L.NaeemH.GustafsonJ. P. (2000). “Triticale: production and utilization,” in Handbook of Cereal Science and Technology, eds K. Klup and J. Ponte J. 2nd edn (New York, NY: Marcel Dekker).
49
DattaJ. K.MondalT.BanerjeeA.MondalN. K. (2011). Assessment of drought tolerance of selected wheat cultivars under laboratory condition. J. Agric. Technol.7, 383–393.
50
DehnaviA. R.ZahediM.LudwiczakA.Cardenas PerezS.PiernikA. (2020). Effect of salinity on seed germination and seedling development of sorghum (Sorghum bicolor (L.) Moench) genotypes. Agronomy10:859. 10.3390/agronomy10060859
51
DongW.WangM.XuF.QuanT.PengK.XiaoL.et al. (2013). Wheat oxophytodienoate reductase gene TaOPR1 confers salinity tolerance via enhancement of abscisic acid signaling and reactive oxygen species scavenging. Plant Physiol.161, 1217–1228. 10.1104/pp.112.211854
52
Duanl. (2020). A novel aba functional analogue b2 enhances salinity tolerance in wheat. Appl. Ecol. Environ. Res.18, 7139–7157. 10.15666/aeer/1805_71397157
53
EgamberdievaD. (2009). Alleviation of salt stress by plant growth regulators and IAA producing bacteria in wheat. Acta Physiol. Plant.31, 861–864. 10.1007/s11738-009-0297-0
54
EhtaiweshF. A.RashedH. F. (2020). Growth and yield responses of libyan hard wheat (Triticum durum Desf) genotypes to salinity stress. Zawia Univ. Bull.22, 33–58.
55
El SabaghA.HossainA.BarutçularC.IqbalM. A.IslamM. S.FahadS.et al. (2020). “Consequences of salinity stress on the quality of crops and its mitigation strategies for sustainable crop production: an outlook of arid and semi-arid regions,” in Environment, Climate, Plant and Vegetation Growth, eds A. Fahad, M. Hasanuzzaman, M. Alam, H. Ullah, M. Saeed, I. A. Khan, and M. Adnan (Cham: Springer), 503–533. 10.1007/978-3-030-49732-3_20
56
El SabaghA.HossainA.BarutçularC.IslamM. S.RatnasekeraD.KumarN.et al. (2019b). Drought and salinity stress management for higher and sustainable canola (Brassica napus L.) production: a critical review. Austral. J. Crop Sci.13, 88–97. 10.21475/ajcs.19.13.01.p1284
57
El SabaghA.HossainA.IslamM. S.BarutcularC.HussainS.HasanuzzamanM.et al. (2019a). Drought and salinity stresses in barley: consequences and mitigation strategies. Austral. J. Crop Sci.13:810. 10.21475/ajcs.19.13.06.p1286
58
El SabaghA.HossainA.IslamM. S.BarutçularC.RatnasekeraD.KumarN.et al. (2019c). Sustainable soybean production and abiotic stress management in saline environments: a critical review. Austr. J. Crop Sci.13, 228–236. 10.21475/ajcs.19.13.02.p1285
59
El-HendawyS.ElshafeiA.Al-SuhaibaniN.AlotabiM.HassanW.DewirY. H.et al. (2019). Assessment of the salt tolerance of wheat genotypes during the germination stage based on germination ability parameters and associated SSR markers. J. Plant Interact.14, 151–163. 10.1080/17429145.2019.1603406
60
El-HendawyS. E.HuY.SchmidhalterU. (2005). Growth, ion content, gas exchange, and water relations of wheat genotypes differing in salt tolerances. Austral. J. Agric. Res.56, 123–134. 10.1071/AR04019
61
El-HendawyS. E.RuanY.HuY.SchmidhalterU. (2009). A comparison of screening criteria for salt tolerance in wheat under field and controlled environmental conditions. J. Agron. Crop Sci.195, 356–367. 10.1111/j.1439-037X.2009.00372.x
62
El-LethyS. R.AbdelhamidM. T.RedaF. (2013). Effect of potassium application on wheat (Triticum aestivum L.) cultivars grown under salinity stress. World Appl. Sci. J.26, 840–850. 10.5829/idosi.wasj.2013.26.07.13527
63
El-YazalM. A. S.EissaH. F.AhmedS. M. A. E.HowladarS. M.ZakiS. N. S.RadyM. M. (2016). The mtlD gene-overexpressed transgenic wheat tolerates salt stress through accumulation of mannitol and sugars. Plant4, 78–90. 10.11648/j.plant.20160406.15
64
ErogluÇ.CabralC.RavnskovS.TopbjergH.WollenweberB. (2020). Arbuscular mycorrhiza influences carbon-use efficiency and grain yield of wheat grown under pre- and post-anthesis salinity stress. Plant Biol.22, 863–871. 10.1111/plb.13123
65
FAO (2009). High Level Expert Forum-How to Feed the World in 2050. Economic and Social Development. Rome: Food and Agricultural Organization of the United Nations.
66
FardusJ.MatinM. A.HasanuzzamanM.HossainM. A.HasanuzzamanM. (2018). Salicylic acid-induced improvement in germination and growth parameters of wheat under salinity stress. J. Anim. Plant Sci.28, 197–207.
67
FarooqS.AzamF. (2005). The use of cell membrane stability (CMS) technique to screen for salt tolerant wheat varieties. J. Plant Physiol.163, 629–637. 10.1016/j.jplph.2005.06.006
68
FaroukS. (2011). Ascorbic acid and α-tocopherol minimize salt-induced wheat leaf senescence. J. Stress Physiol. Biochem.7, 58–79.
69
Fernandez-FigaresI.MarinettoJ.RoyoC.RamosJ. M.Del MoralL. G. (2000). Amino-acid composition and protein and carbohydrate accumulation in the grain of triticale grown under terminal water stress simulated by a senescing agent. J. Cereal Sci.32, 249–258. 10.1006/jcrs.2000.0329
70
FlowersT. J.HajibagherpM. A.YeoA. R. (1991). Ion accumulation in the cell walls of rice plants growing under saline conditions: evidence for the Oertli hypothesis. Plant Cell Environ.14, 319–325. 10.1111/j.1365-3040.1991.tb01507.x
71
Food and Agriculture Organization (FAO) of the United Nations (2016). Pulses: Nutritious Seeds for a Sustainable Future. Rome: Food and Agriculture Organization of the United Nations.
72
FrancoisL. E.MaasE. V.DonovanT. J.YoungsV. L. (1986). Effect of salinity on grain yield and quality, vegetative growth, and germination of semi-dwarf and durum wheat. Agron. J.78, 1053–1058. 10.2134/agronj1986.00021962007800060023x
73
FrankA. B.BauerA.BlackA. I. (1987). Effects of air temperature and water stress on apex development in spring wheat. Crop Sci.27, 113–116. 10.2135/cropsci1987.0011183X002700010028x
74
Garcia del MoralL. F.BoujennaA.YanezJ. A.RamosJ. M. (1995). Forage production, grain yield, and protein content in dual-purpose triticale grown for both grain and forage. Agron. J.87, 902–908. 10.2134/agronj1995.00021962008700050021x
75
GardnerW. K. (2016). Sodium, calcium and magnesium ratios in soils of NW Victoria, Australia may restrict root growth and crop production. J. Plant Nutr.39, 1205–1215. 10.1080/01904167.2014.999946
76
GeilfusC. M. (2018a). Chloride from nutrient to toxicant. Plant Cell Physiol.59, 877–886. 10.1093/pcp/pcy071
77
GeilfusC. M. (2018b). Review on the significance of chlorine for crop yield and quality. Plant Sci.270, 114–122. 10.1016/j.plantsci.2018.02.014
78
GhoshB.MdN. A.GantaitS. (2016). Response of rice under salinity stress: a review update. Rice Res.4:167. 10.4172/2375-4338.1000167
79
Gil-MuñozF.Pérez-PérezJ. G.QuiñonesA.Primo-CapellaA.CebollaJ.Forner-GinerM. Á.et al. (2020). A cross population between D. kaki and D. virginiana shows high variability for saline tolerance and improved salt stress tolerance. PLoS ONE15:e0229023. 10.1371/journal.pone.0229023
80
GiraldoP.BenaventeE.Manzano-AgugliaroF.GimenezE. (2019). Worldwide research trends on wheat and barley: a bibliometric comparative analysis. Agronomy9:352. 10.3390/agronomy9070352
81
GolldackD.LiC.MohanH.ProbstN. (2014). Tolerance to drought and salt stress in plants: unraveling the signaling networks. Front. Plant Sci.5:151. 10.3389/fpls.2014.00151
82
GrieveC. M.FrancoisL. E.MaasE. V. (1994). Salinity affects the timing of phasic development in spring wheat. Crop Sci.34, 1544–1549. 10.2135/cropsci1994.0011183X003400060024x
83
GulB.KhanM. A.WeberD. J. (2000). Alleviation of salinity and dark-enforced dormancy in Allenrolfea occidentalis seeds under various thermoperiods. Austral. J. Bot.48, 745–752. 10.1071/BT99069
84
HaninM.EbelC.NgomM.LaplazeL.MasmoudiK. (2016). New insights on plant salt tolerance mechanisms and their potential use for breeding. Front. Plant Sci.7:1787. 10.3389/fpls.2016.01787
85
HasanA.HafizH. R.SiddiquiN.KhatunM.IslamR.MamunA. A. (2015). Evaluation of wheat genotypes for salt tolerance based on some physiological traits. J. Crop Sci. Biotechnol.18, 333–340. 10.1007/s12892-015-0064-2
86
HasanuzzamanM.AlamM.RahmanA.HasanuzzamanM.NaharK.FujitaM. (2014). Exogenous proline and glycine betaine mediated upregulation of antioxidant defense and glyoxalase systems provides better protection against salt-induced oxidative stress in two rice (Oryza sativa L.) varieties. BioMed. Res. Int.2014:757219. 10.1155/2014/757219
87
HasanuzzamanM.HossainM. A.FujitaM. (2011). Selenium-induced up-regulation of the antioxidant defense and methylglyoxal detoxification system reduces salinity-induced damage in rapeseed seedlings. Biol. Trace Element Res.143, 1704–1721. 10.1007/s12011-011-8958-4
88
HasanuzzamanM.NaharK.FujitaM. (2013). “Plant responses to salt stress and role of exogenous protectants to mitigate salt-induced damages,” in Ecophysiology and Responses of Plants Under Salt Stress, eds P. Ahmad P, M. M. Azooz, and M. N. V. Prasad MNV (New York, NY: Springer), 25–87. 10.1007/978-1-4614-4747-4_2
89
HassaneinR. A.HassaneinA. A.HaiderA. S.HashemH. A. (2009). Improving salt tolerance of Zea mays L. plants by presoaking their grains in glycine betaine. Austral. J. Basic Appl. Sci.3, 928–942.
90
HawkinsH. J.LewisO. A. M. (1993). Combination effect of NaCl salinity, nitrogen form and calcium concentration on the growth, ionic content and gaseous exchange properties of Triticum aestivum L. cv. Gamtoos. New Phytol.124, 161–170. 10.1111/j.1469-8137.1993.tb03806.x
91
HayatS.KhaliqueG.WaniA. S.AlyemeniM. N.AhmadA. (2014). Protection of growth in response to 28-homobrassinolide under the stress of cadmium and salinity in wheat. Int. J. Biol. Macromol.64, 130–136. 10.1016/j.ijbiomac.2013.11.021
92
HeC.YangA.ZhangW.GaoQ.ZhangJ. (2010). Improved salt tolerance of transgenic wheat by introducing betA gene for glycine betaine synthesis. Plant Cell Tissue Organ Cult.101, 65–78. 10.1007/s11240-009-9665-0
93
HossainM. A.HoqueT. S.ZaidA.WaniS. H.MostofaM. G.HenryR. (2021). “Targeting the ascorbate-glutathione pathway and the glyoxalase pathway for genetic engineering of abiotic stress-tolerance in rice,” in Molecular Breeding for Rice Abiotic Stress Tolerance and Nutritional Quality, eds M. A. Hossain, L. Hassan, K. M. Iftekharuddaula, A. Kumar A, and R. Henry R (Wiley-Blackwell), 398–427. 10.1002/9781119633174.ch21
94
HoushmandS.ArzaniA.Mirmohammadi-MaibodyS. A. M. (2014). Effects of salinity and drought stress on grain quality of durum wheat. Commun. Soil Sci. Plant Anal.45, 297–308. 10.1080/00103624.2013.861911
95
HuY.SchmidhalterU. (1998). Spatial distribution sand net deposition rates of mineral elements in the elongating wheat (Triticum aestivum L.) leaf under saline soil conditions. Planta204, 212–219. 10.1007/s004250050249
96
HuangM.ChaiL.JiangD.ZhangM.ZhaoY.HuangY. (2019). Increasing aridity affects soil archaeal communities by mediating soil niches in semi-arid regions. Sci. Total Environ.647, 699–707. 10.1016/j.scitotenv.2018.07.305
97
HuebnerF. R.NelsenT. C.ChungO. K.BietzJ. A. (1997). Protein distributions among hard red winter wheat varieties as related to environment and baking quality. Cereal Chem.74, 123–128. 10.1094/CCHEM.1997.74.2.123
98
HussainS.ShaukatM.AshrafM.ZhuC.JinQ.ZhangJ. (2019). Salinity stress in arid and semi-arid climates: Effects and management in field crops. Clim. Change Agric123–145. 10.5772/intechopen.87982
99
HütschB. W.HeW.SchubertS. (2016). Nitrogen nutritional status of young maize plants (Zea mays) is not limited by NaCl stress. J. Plant Nutr. Soil Sci.179, 775–783. 10.1002/jpln.201500565
100
IoannouM.CoutsogeorgopoulosC. (1997). Kinetic studies on the activation of eukaryotic peptidyltransferase by potassium. Arch. Biochem. Biophys.345, 325–331. 10.1006/abbi.1997.0256
101
IqbalM.AshrafM. (2007). Seed treatment with auxins modulates growth and ion partitioning in salt-stressed wheat plants. J. Integrat. Plant Biol.49, 1003–1015. 10.1111/j.1672-9072.2007.00488.x
102
IqbalM.AshrafM.JamilA. (2006). Seed enhancement with cytokinins: changes in growth and grain yield in salt stressed wheat plants. Plant Growth Regulat.50, 29–39. 10.1007/s10725-006-9123-5
103
IqbalM.IrshadS.NadeemM.FatimaT.ItratA. B. (2018). Salinity effects on wheat (Triticum aestivum L.) characteristics: a review article. Int. J Agric. Biol.12, 1–15. 10.12692/ijb/12.3.131-146
104
IqbalM. A.JunaidR.WajidN.SabryH.YassirK.AymanS. (2021). Rainfed winter wheat (Triticum aestivum L.) cultivars respond differently to integrated fertilization in Pakistan. Fresenius Environ. Bull.30, 3115–3121.
105
IslamM. S.AkhterM. M.El SabaghA.LiuL. Y.NguyenN. T.UedaA.et al. (2011). Comparative studies on growth and physiological responses to saline and alkaline stresses of Foxtail millet (Setaria italica L.) and Proso millet (Panicum miliaceum L.). Austral. J. Crop Sci.5:1269.
106
JamesR. A.MunnsR.Von CaemmererS.TrejoC.MillerC.CondonT. (2006). Photosynthetic capacity is related to the cellular and subcellular partitioning of Na+, K+ and Cl-in salt-affected barley and durum wheat. Plant Cell Environ.29, 2185–2197. 10.1111/j.1365-3040.2006.01592.x
107
JanA. U.HadiF.NawazM. A.RahmanK. (2017). Potassium and zinc increase tolerance to salt stress in wheat (Triticum aestivum L.). Plant Physiol. Biochem.116, 139–149. 10.1016/j.plaphy.2017.05.008
108
JennerC. F.UgaldeT. D.AspinallD. (1991). The physiology of starch and protein deposition in the endosperm of wheat. Funct. Plant Biol.18, 211–226. 10.1071/PP9910211
109
KahriziS.SedghiM. (2013). Effect of salt stress on grain reserve composition in ten durum wheat cultivars. J. Stress Physiol. Biochem.3, 113–121.
110
KalhoroN. A.RajparI.KalhoroS. A.AliA.RazaS.AhmedM.et al. (2016). Effect of salts stress on the growth and yield of wheat (Triticum aestivum L.). Am. J. Plant Sci.7:2257. 10.4236/ajps.2016.715199
111
KaruppanapandianT.MoonJ. C.KimC.ManoharanK.KimW. (2011). Reactive oxygen species in plants: their generation, signal transduction, and scavenging mechanisms. Austral. J. Crop Sci.5, 709–725.
112
KaterjiN.Van HoornJ. W.FaresC.HamdyA.MastrorilliM.OweisT. (2005). Salinity effect on grain quality of two durum wheat varieties differing in salt tolerance. Agric. Water Manage.75, 85–91. 10.1016/j.agwat.2004.12.005
113
KaurH.BhardwajR. D.GrewalS. K. (2017). Mitigation of salinity-induced oxidative damage in wheat (Triticum aestivum L.) seedlings by exogenous application of phenolic acids. Acta Physiol. Plant. 39:221. 10.1007/s11738-017-2521-7
114
KeQ.YeJ.WangB.RenJ.YinL.DengX.et al. (2018). Melatonin mitigates salt stress in wheat seedlings by modulating polyamine metabolism. Front. Plant Sci.9:914. 10.3389/fpls.2018.00914
115
KhanA.AhmadI.ShahA.AhmadF.GhaniA.NawazM.et al. (2013). Amelioration of salinity stress in wheat (Triticum aestivum L.) by foliar application of phosphorus. Phyton82, 281–287. 10.32604/phyton.2013.82.281
116
KhanA. L.WaqasM.AsafS.KamranM.ShahzadR.BilalS.et al. (2017). Plant growth-promoting endophyte Sphingomonas sp. LK11 alleviates salinity stress in Solanum pimpinellifolium. Environ. Exp. Bot.133, 58–69. 10.1016/j.envexpbot.2016.09.009
117
KhanM. A.GulB.WeberD. J. (2004). Action of plant growth regulators and salinity on seed germination of Ceratoides lanata. Canad. J. Bot.82, 37–42. 10.1139/b03-140
118
KhanM. I. R.IqbalN.MasoodA.KhanN. A. (2012). Variation in salt tolerance of wheat cultivars: role of glycinebetaine and ethylene. Pedosphere22, 746–754. 10.1016/S1002-0160(12)60060-5
119
KhanN. A.ShamimM.ShambhooP. (2008). Biochemical changes in wheat plants in response to salinity. Int. J. Plant Sci.3, 11–15.
120
KhataarM.MohammadiM. H.ShabaniF. (2018). Soil salinity and matric potential interaction on water use, water use efficiency and yield response factor of bean and wheat. Sci. Rep.8:2679. 10.1038/s41598-018-20968-z
121
KizilgeciF.YildirimM.IslamM. S.RatnasekeraD.IqbalM. A.SabaghA. E. (2021). Normalized difference vegetation index and chlorophyll content for precision nitrogen management in durum wheat cultivars under semi-arid conditions. Sustainability13:3725. 10.3390/su13073725
122
KolbertZ.FeiglG.FreschiL.PoórP. (2019). Gasotransmitters in action: nitric oxide-ethylene crosstalk during plant growth and abiotic stress responses. Antioxidants8:167. 10.3390/antiox8060167
123
KosováK.PrášilI. T.VítámvásP.DobrevP.MotykaV.FlokováK.et al. (2012). Complex phytohormone responses during the cold acclimation of two wheat cultivars differing in cold tolerance, winter Samanta and spring Sandra. J. Plant Physiol.169, 567–576. 10.1016/j.jplph.2011.12.013
124
Kotuby-AmazherJ.KoenigK.KitchenB. (2000). Salinity and Plant Tolerance. Available online at: https://extension.usu.edu/files/publications/publication/AG-SO-03.pdf (accessed June 20, 2020).
125
KumariA.KaurR. (2018). Evaluation of benzyl-butyl phthalate induced germination and early growth vulnerability to barley seedlings (Hordeum vulgare L.). Indian J. Ecol.45, 174–177.
126
KumariA.KaurR. (2020). A review on morpho-physiological traits of plants under phthalates stress and insights into their uptake and translocation. Plant Growth Regul.91, 327–347. 10.1007/s10725-020-00625-0
127
KunduP.GillR.AhlawatS.AnjumN. A.SharmaK. K.AnsariA. A.et al. (2018). “Targeting the redox regulatory mechanisms for abiotic stress tolerance in crops” in Biochemical, Physiological and Molecular Avenues for Combating Abiotic Stress Tolerance in Plants, ed S. H. Wani (Elsevier Academic Press), 151–220. 10.1016/B978-0-12-813066-7.00010-3
128
Läuchli AA.GrattanS. R. (2007). “Plant growth and development under salinity stress,” in Advances in Molecular Breeding Toward Drought and Salt Tolerant Crops, eds M. A. Jenks, P. M. Hasegawa, and S. M. Jain (Dordrecht: Springer), 1–32. 10.1007/978-1-4020-5578-2_1
129
LiP.CaiJ.LuoX.ChangT.LiJ.ZhaoY.et al. (2019). Transformation of wheat Triticum aestivum with the HvBADH1 transgene from hulless barley improves salinity-stress tolerance. Acta. Physiol. Plant41:155. 10.1007/s11738-019-2940-8
130
LiuX.ChenD.YangT.HuangF.FuS.LiL. (2020). Changes in soil labile and recalcitrant carbon pools after land-use change in a semi-arid agro-pastoral ecotone in Central Asia. Ecol. Indic.110:105925. 10.1016/j.ecolind.2019.105925
131
LlanesA.AndradeA.AlemanoS.LunaV. (2016). Alterations of endogenous hormonal levels in plants under drought and salinity. Am. J. Plant Sci.7:1357. 10.4236/ajps.2016.79129
132
MaasE. V. (1990). “Crop salt tolerance,” in Agricultural Salinity Assessment and Management. ASCE Publications, ed K. K. Tanji (Reston, VA), 262–303.
133
MaasE. V.GrieveC. M. (1990). Spike and leaf development of sal-stressed wheat. Crop Sci.30, 1309–1313. 10.2135/cropsci1990.0011183X003000060031x
134
MakhloufiE.YousfiF. E.MarandeW.MilaI.HananaM.BergèsH.et al. (2014). Isolation and molecular characterization of ERF1, an ethylene response factor gene from durum wheat (Triticum turgidum L. subsp. durum), potentially involved in salt-stress responses. J. Exp. Bot. 5, 6359–6371. 10.1093/jxb/eru352
135
MandhaniaS.MadanS.SawhneyV. (2006). Antioxidant defense mechanism under salt stress in wheat seedlings. Biol. Plant.50, 227–231. 10.1007/s10535-006-0011-7
136
MaoX.ZhangH.TianS.ChangX.JingR. (2010). TaSnRK2. 4, an SNF1-type serine/threonine protein kinase of wheat (Triticum aestivum L.), confers enhanced multistress tolerance in Arabidopsis. J. Exp. Bot.61, 683–696. 10.1093/jxb/erp331
137
MaqsoodT.AkhtarJ.FarooqM. R.HaqM. A.SaqibZ. A. (2008). Biochemical attributes of salt tolerant and salt sensitive maize cultivars to salinity and potassium nutrition. Pakistan J. Agric. Sci.45, 1–5.
138
MassaD.MattsonN. S.LiethH. J. (2009). Effects of saline root environment (NaCl) on nitrate and potassium uptake kinetics for rose plants: a Michaelis–Menten modelling approach. Plant Soil318, 101–115. 10.1007/s11104-008-9821-z
139
MbarkiS.SytarO.ZivcakM.AbdellyC.CerdaA.BresticM. (2018). Anthocyanins of coloured wheat genotypes in specific response to salstress. Molecules23:1518. 10.3390/molecules23071518
140
MohsenzadehS.ZohrabiM. (2018). Auxin and sodium nitroprusside effects on wheat antioxidants in salinity. Russian J. Plant Physiol.65, 651–657. 10.1134/S1021443718050138
141
MunnsR.JamesR. A.LäuchliA. (2006). Approaches to increasing the salt tolerance of wheat and other cereals. J. Exp. Bot.57, 1025–1043. 10.1093/jxb/erj100
142
MunnsR.TesterM. (2008). Mechanisms of salinity tolerance. Ann. Rev. Plant Biol.59, 651–681. 10.1146/annurev.arplant.59.032607.092911
143
MushtaqA.JamilN.RiazM.HornyakG. L.AhmedN.AhmedS. S.et al. (2017). Synthesis of silica nanoparticles and their effect on priming of wheat (Triticum aestivum L.) under salinity stress. Biol. Forum9, 150–157.
144
NadeemM.TariqM. N.AmjadM.SajjadM.AkramM.ImranM.et al. (2020). Salinity-induced changes in the nutritional quality of bread wheat (Triticum aestivum L.) genotypes. Agrivita42, 1–12. 10.17503/agrivita.v42i1.2273
145
NaiduC. V. (2001). Improvement of seed germination in red sanders (Pterocarpus santalinus Linn. F.) by plant growth regulators. Indian J. Plant Physiol.6, 205–207.
146
NassarR.KamelH. A.GhoniemA. E.AlarcónJ. J.SekaraA.UlrichsC.et al. (2020). Physiological and anatomical mechanisms in wheat to cope with salt stress induced by seawater. Plants9:237. 10.3390/plants9020237
147
NavarroC.MooreJ.OttA.BaumertE.MohanA.GillK. S.et al. (2015). Evolutionary, comparative and functional analyses of the brassinosteroid receptor gene, BRI1, in wheat and its relation to other plant genomes. PLoS ONE10:e0127544. 10.1371/journal.pone.0127544
148
Navarro-YepesJ.BurnsM.AnandhanA.KhalimonchukO.Del RazoL. M.Quintanilla-VegaB.et al. (2014). Oxidative stress, redox signaling, and autophagy: cell death versus survival. Antioxidants Redox Signal.21, 66–85. 10.1089/ars.2014.5837
149
NetondoG. W.OnyangoJ. C.BeckE. (2004). Sorghum and salinity: II. gas exchange and chlorophyll fluorescence of sorghum under salt stress. Crop Sci.44, 806–811. 10.2135/cropsci2004.8060
150
NishidaK.KhanN. M.ShiozawaS. (2009). Effects of salt accumulation on the leaf water potential and transpiration rate of pot-grown wheat with a controlled saline groundwater table. Soil Sci. Plant Nutr.55, 375–384. 10.1111/j.1747-0765.2009.00368.x
151
NishiyamaR.WatanabeY.FujitaY.LeD. T.KojimaM.WernerT.et al. (2011). Analysis of cytokinin mutants and regulation of cytokinin metabolic genes reveals important regulatory roles of cytokinins in drought, salt and abscisic acid responses, and abscisic acid biosynthesis. Plant Cell23, 2169–2183. 10.1105/tpc.111.087395
152
NiuX.BressanR. A.HasegawaP. M.PardoJ. M. (1995). Ion homeostasis in NaCl stress environments. Plant Physiol.109:735. 10.1104/pp.109.3.735
153
NoreenS.FatimaK.AtharH. U. R.AhmadS.HussainK. (2017). Enhancement of physio-biochemical parameters of wheat through exogenous application of salicylic acid under drought stress. J. Anim. Plant Sci.27, 153–163.
154
OrhanF. (2016). Alleviation of salt stress by halotolerant and halophilic plant growth-promoting bacteria in wheat (Triticum aestivum). Brazil. J. Microbiol.47, 621–627. 10.1016/j.bjm.2016.04.001
155
Oria-HernándezJ.CabreraN.Pérez-MontfortR.Ramírez-SilvaL. (2005). Pyruvate kinase revisited the activating effect of k+. J. Biol. Chem.280, 37924–37929. 10.1074/jbc.M508490200
156
OtuH.CeliktasV.DuzenliS.HossainA.El SabaghA. (2018). Germination and early seedling growth of five durum wheat cultivars (Triticum durum Desf.) is affected by different levels of salinity. Fresenius Environ. Bull.27, 7746–7757.
157
ParidaA. K.MittraB.DasA. B.DasT. K.MohantyP. (2005). High salinity reduces the content of a highly abundant 23-kDa protein of the mangrove Bruguiera parviflora. Planta221, 135–140. 10.1007/s00425-004-1415-2
158
ParkS. H.WilsonJ. D.SeabournB. W. (2009). Starch granule size distribution of hard red winter and hard red spring wheat: its effects on mixing and breadmaking quality. J. Cereal Sci.49, 98–105. 10.1016/j.jcs.2008.07.011
159
Plaza-WüthrichS.BlöschR.RindisbacherA.CannarozziG.TadeleZ. (2016). Gibberellin deficiency confers both lodging and drought tolerance in small cereals. Front. Plant Sci.7:643. 10.3389/fpls.2016.00643
160
PoustiniK.SiosemardehA. (2004). Ion distribution in wheat cultivars in response to salinity stress. Field Crops Res.85, 125–133. 10.1016/S0378-4290(03)00157-6
161
QamarH.IlyasM.JanS. A.MustafaH. S. B.ArshadA.YarM. S.et al. (2020). Recent trends in molecular breeding and biotechnology for the genetic improvement of Brassica species against drought stress. Fresenius Environ. Bull.29, 19–25.
162
RahmanM. A.ChikushiJ.YoshidaS.YahataH.YasunagaE. (2005). Effect of high air temperature on grain growth and yields of wheat genotypes differing in heat tolerance. J. Agric. Meteorol.60, 605–608. 10.2480/agrmet.605
163
RakhmankulovaZ. F.ShuyskayaE. V.ShcherbakovA. V.FedyaevV. V.BiktimerovaG. Y.KhafisovaR. R.et al. (2015). Content of proline and flavonoids in the shoots of halophytes inhabiting the South Urals. Russian J. Plant Physiol.62, 71–79. 10.1134/S1021443715010112
164
RaoA. C. S.SmithJ. L.JandhyalaV. K.PapendickR. I.ParrJ. F. (1993). Cultivar and climatic effects on the protein content of soft white winter wheat. Agron. J.85, 1023–1028. 10.2134/agronj1993.00021962008500050013x
165
ReddyB. V. S.ReddyP. S.BidingerF.BlümmelM. (2003). Crop management factors influencing yield and quality of crop residues. Field Crops Res.84, 57–77. 10.1016/S0378-4290(03)00141-2
166
RichardsonA. E.SimpsonR. J. (2011). Soil microorganisms mediating phosphorus availability update on microbial phosphorus. Plant Physiol.156, 989–996. 10.1104/pp.111.175448
167
RiyazuddinR.VermaR.SinghK.NishaN.KeishamM.BhatiK. K.et al. (2020). Ethylene: a master regulator of salinity stress tolerance in plants. Biomolecules10:959. 10.3390/biom10060959
168
RongW.QiL.WangA.YeX.DuL.LiangH.et al. (2014). The ERF transcription factor Ta ERF 3 promotes tolerance to salt and drought stresses in wheat. Plant Biotechnol. J.12, 468–479. 10.1111/pbi.12153
169
RoyoA.AbióD. (2003). Salt tolerance in durum wheat cultivars. Spanish J. Agric. Res.1, 27–36. 10.5424/sjar/2003013-32
170
RyuH.ChoY. G. (2015). Plant hormones in salt stress tolerance. J. Plant Biol.58, 147–155. 10.1007/s12374-015-0103-z
171
SabooraA.KiarostamiK.BehroozbayatiF.HajihashemiS. (2006). Salinity (NaCl) tolerance of wheat genotypes at germination and early seedling growth. Pakistan J. Biol. Sci.9, 2009–2021. 10.3923/pjbs.2006.2009.2021
172
SairamR. K.RaoK. V.SrivastavaG. C. (2002). Differential response of wheat genotypes to long term salinity stress in relation to oxidative stress, antioxidant activity and osmolyte concentration. Plant Sci.163, 1037–1046. 10.1016/S0168-9452(02)00278-9
173
SamadR.KarmokerJ. L. (2012). Effects of gibberellic acid and Kn on seed germination and accumulation of Na+ and K+ in the seedlings of triticale-I under salinity stress. Bangladesh J. Bot.41, 123–129. 10.3329/bjb.v41i2.13435
174
SawahelW. A.HassanA. H. (2002). Generation of transgenic wheat plants producing high levels of the osmoprotectant proline. Biotechnol. Lett.24, 721–725. 10.1023/A:1015294319114
175
SchofieldJ. D. (1994). “Wheat proteins: structure and functionality in milling and breadmaking,” in Wheat, eds W. Bushuk and V. F. Rasper (Boston, MA: Springer), 73–106. 10.1007/978-1-4615-2672-8_7
176
SchwechheimerC. (2012). Gibberellin signaling in plants–the extended version. Front. Plant Sci.2:107. 10.3389/fpls.2011.00107
177
SedaghatM.SarvestaniZ. T.EmamY.BidgoliA. M. (2017). Do phytohormones influence the grain quality and yield of winter wheat under drought conditions?J. Adv. Agric. Technol.4, 151–158. 10.18178/joaat.4.2.151-158
178
ShaddadM. A. K.HMA. E. S.MostafaD. (2013). Role of gibberellic acid (GA3) in improving salt stress tolerance of two wheat cultivars. Int. J. Plant Physiol. Biochem.5, 50–57. 10.5897/IJPPB2011.055
179
ShafiM.ZhangG.BakhtJ.KhanM. A.IslamU. E.KhanM. D.et al. (2010). Effect of cadmium and salinity stresses on root morphology of wheat. Pakistan J. Bot.42, 2747–2754.
180
ShahidS. A.ZamanM.HengL. (2018). “Introduction to soil salinity, sodicity and diagnostics techniques,” in Guideline for Salinity Assessment, Mitigation and Adaptation Using Nuclear and Related Techniques, eds M. Zaman, S. A. Shahid, and L. Heng (Cham: Springer), 1–42. 10.1007/978-3-319-96190-3_1
181
ShakirovaF. M.AvalbaevA. M.BezrukovaM. V.FatkhutdinovaR. A.MaslennikovaD. R.YuldashevR. A. (2012). “Hormonal intermediates in the protective action of exogenous phytohormones in wheat plants under salinity,” in Phytohormones and Abiotic Stress Tolerance in Plants, eds N. Khan, R. Nazar, N. Iqbal, and N. Anjum (Berlin; Heidelberg: Springer), 185–228. 10.1007/978-3-642-25829-9_9
182
ShakirovaF. M.SakhabutdinovaA. R.BezrukovaM. V.FatkhutdinovaR. A.FatkhutdinovaD. R. (2003). Changes in the hormonal status of wheat seedlings induced by salicylic acid and salinity. Plant Sci.164, 317–322. 10.1016/S0168-9452(02)00415-6
183
SharbatkhariM.ShobbarZ. S.GaleshiS.NakhodaB. (2016). Wheat stem reserves and salinity tolerance: molecular dissection of fructan biosynthesis and remobilization to grains. Planta244, 191–202. 10.1007/s00425-016-2497-3
184
SharmaP.JhaA. B.DubeyR. S.PessarakliM. (2012). Reactive oxygen species, oxidative damage, and antioxidative defense mechanism in plants under stressful conditions. J. Bot. 2012. 10.1155/2012/217037
185
ShenY.GuoW.ZhouY.ZhuX.FengC.PengY. (2007). Effects of salinity stress on the dynamic changes in the accumulation of grain protein and its components in wheat. J. Triticeae Crops26, 100–103.
186
SiddiquiM. H.IqbalM. A.WajidN.ImtiazH.KhaliqA. (2019). Bio-economic viability of rainfed wheat (Triticum aestivum L.) cultivars under integrated fertilization regimes in Pakistan. Custos e Agronegocio15, 81–96.
187
SinghR. P.JhaP.JhaP. N. (2015). The plant-growth-promoting bacterium Klebsiella sp. SBP-8 confers induced systemic tolerance in wheat (Triticum aestivum) under salt stress. J. Plant Physiol.184, 57–67. 10.1016/j.jplph.2015.07.002
188
SorourS. G.AiadM. A.AhmedA. A.HenashM. I. A.MetwalyE. M.AlharbyH.et al. (2019). Yield of wheat is increased through improving the chemical properties, nutrient availability and water productivity of salt affected soils in the north delta of Egypt. Appl. Ecol. Environ. Res.17, 8291–8306. 10.15666/aeer/1704_82918306
189
SpeerM.KaiserW. M. (1991). Ion relations of symplastic and apoplastic space in leaves from Spinacia oleracea L. and Pisum sativum L. under salinity. Plant Physiol.97, 990–997. 10.1104/pp.97.3.990
190
SreenivasuluN.SoporyS. K.KishorP. K. (2007). Deciphering the regulatory mechanisms of abiotic stress tolerance in plants by genomic approaches. Gene388, 1–13. 10.1016/j.gene.2006.10.009
191
SuzukiK.YamajiN.CostaA.OkumaE.KobayashiN. I.KashiwagiT.et al. (2016). OsHKT1; 4-mediated Na+ transport in stems contributes to Na+ exclusion from leaf blades of rice at the reproductive growth stage upon salt stress. BMC Plant Biol.16:22. 10.1186/s12870-016-0709-4
192
SytarO.MbarkiS.ZivcakM.BresticM. (2018). “The involvement of different secon dary metabolites in salinity tolerance of crops,” in Salinity Responses and Tolerance in Plants, eds V. Kumar, S. Wani, P. Suprasanna, and L. S. Tran. Vol. 2. (Cham: Springer), 21–48. 10.1007/978-3-319-90318-7_2
193
TabatabaeiS. A. (2013). The effect of salicylic acid and gibberellin on enzyme activity and germination characteristics of wheat seeds under salinity stress conditions. Int. J. Agric. Crop Sci.6, 236–240.
194
TammamA. A.AlhamdM. F. A.HemedaM. M. (2008). Study of salt tolerance in wheat (Triticum aestium L.) cultivar Banysoif 1. Austral. J. Crop Sci.1, 115–125.
195
TareqM. Z.HossainM. A.MojakkirM. A.AhmedR.FakirM. S. A. (2011). Effect of salinity on reproductive growth of wheat. Bangladesh J. Seed Sci. Technol.15, 111–116.
196
ThomasG. W.SwobodaA. R. (1970). Anion exclusion effects on chloride movement in soils. Soil Sci.110, 163–166. 10.1097/00010694-197009000-00003
197
TianS.MaoX.ZhangH.ChenS.ZhaiC.YangS.et al. (2013). Cloning and characterization of TaSnRK2. 3, a novel SnRK2 gene in common wheat. J. Exp. Bot.64, 2063–2080. 10.1093/jxb/ert072
198
TianX.HeM.WangZ.ZhangJ.SongY.HeZ.et al. (2015). Application of nitric oxide and calcium nitrate enhances tolerance of wheat seedlings to salt stress. Plant Growth Regulat.77, 343–356. 10.1007/s10725-015-0069-3
199
TroccoliA.BorrelliG. M.De VitaP.FaresC.Di FonzoN. (2000). Mini review: durum wheat quality: a multidisciplinary concept. J. Cereal Sci.32, 99–113. 10.1006/jcrs.2000.0322
200
TuranM. A.ElkarimA. H. A.TabanN.TabanS. (2009). Effect of salt stress on growth, stomatal resistance, proline and chlorophyll concentrations on maize plant. Afr. J. Agric. Res.4, 893–897. 10.5897/AJAR.9000223
201
UmezawaT.SugiyamaN.MizoguchiM.HayashiS.MyougaF.Yamaguchi-ShinozakiK.et al. (2009). Type 2C protein phosphatases directly regulate abscisic acid-activated protein kinases in Arabidopsis. Proc. Natl. Acad. Sci. U.S.A.106, 17588–17593. 10.1073/pnas.0907095106
202
Van LoonL. C. (2007). “Plant responses to plant growth-promoting rhizobacteria,” in New Perspectives and Approaches in Plant Growth-Promoting Rhizobacteria Research, eds P. A. H. M. Bakker, J. M. Raaijmakers, G. Bloemberg, M. Höfte, P. Lemanceau, and B. M. Cooke (Dordrecht: Springer), 243–54. 10.1007/978-1-4020-6776-1_2
203
WajidM.KhanM. A.ShiraziM. U.SummiyaF. (2019). Seed priming modulates germination potential, osmoprotectants accumulation and ionic uptake in wheat seedlings under salt stress. Int. J. Agric. Biol.22, 594–600.
204
WakeelA.FarooqM.QadirM.SchubertS. (2011). Potassium substitution by sodium in plants. Critic. Rev. Plant Sci.30, 401–413. 10.1080/07352689.2011.587728
205
WangY.MopperS.HasensteinK. H. (2001). Effects of salinity on endogenous ABA, IAA, JA, and SA in Iris hexagona. J. Chem. Ecol.27, 327–342. 10.1023/A:1005632506230
206
WilkinsonS.KudoyarovaG. R.VeselovD. S.ArkhipovaT. N.DaviesW. J. (2012). Plant hormone interactions: innovative targets for crop breeding and management. J. Exp. Bot.63, 3499–3509. 10.1093/jxb/ers148 10.1093/jxb/ers148
207
XueZ. Y.ZhiD. Y.XueG. P.ZhangH.ZhaoY. X.XiaG. M. (2004). Enhanced salt tolerance of transgenic wheat (Tritivum aestivum L.) expressing a vacuolar Na+/H+ antiporter gene with improved grain yields in saline soils in the field and a reduced level of leaf Na+. Plant Sci.167, 849–859. 10.1016/j.plantsci.2004.05.034
208
YangT.YaoS.HaoL.ZhaoY.LuW.XiaoK. (2016). Wheat bHLH-type transcription factor gene TabHLH1 is crucial in mediating osmotic stresses tolerance through modulating largely the ABA-associated pathway. Plant Cell Rep.35, 2309–2323. 10.1007/s00299-016-2036-5
209
YousfiS.SerretM. D.ArausJ. L. (2013). Comparative response of δ13C, δ18O and δ15N in durum wheat exposed to salinity at the vegetative and reproductive stages. Plant Cell Environ.36, 1214–1227. 10.1111/pce.12055
210
YuldashevR.AvalbaevA.BezrukovaM.VysotskayaL.KhripachV.ShakirovaF. (2012). Cytokinin oxidase is involved in the regulation of cytokinin content by 24-epibrassinolide in wheat seedlings. Plant Physiol. Biochem.55, 1–6. 10.1016/j.plaphy.2012.03.004
211
YurekliF.PorgaliZ. B.TurkanI. (2004). Variations in abscisic acid, indole-3-acetic acid, gibberellic acid and zeatin concentrations in two bean species subjected to salt stress. Acta Biol. Cracoviensia Series Botanica, 46, 201–212.
212
ZamanB.NiaziB. H.AtharM.AhmadM. (2005). Response of wheat plants to sodium and calcium ion interaction under saline environment. Int. J. Environ. Sci. Technol.2, 7–12. 10.1007/BF03325852
213
ZhangL.XieJ.WangL.SiL.ZhengS.YangY.et al. (2020). Wheat TabZIP8, 9, 13 participate in ABA biosynthesis in NaCl-stressed roots regulated by TaCDPK9-1. Plant Physiol. Biochem.151, 650–658. 10.1016/j.plaphy.2020.03.039
214
ZhangS.GanY.XuB. (2016). Application of plant-growth-promoting fungi Trichoderma longibrachiatum T6 enhances tolerance of wheat to salt stress through improvement of antioxidative defense system and gene expression. Front. Plant Sci.7:1405. 10.3389/fpls.2016.01405
215
ZhangX.ShiZ.TianY.ZhouQ.CaiJ.DaiT.et al. (2016). Salt stress increases content and size of glutenin macropolymers in wheat grain. Food Chem.197, 516–521. 10.1016/j.foodchem.2015.11.008
216
ZhaoY.AiX.WangM.XiaoL.XiaG. (2016). A putative pyruvate transporter TaBASS2 positively regulates salinity tolerance in wheat via modulation of ABI4 expression. BMC Plant Biol.16:109. 10.1186/s12870-016-0795-3
217
ZhengY.WangZ.SunX.JiaA.JiangG.LiZ. (2008). Higher salinity tolerance cultivars of winter wheat relieved senescence at reproductive stage. Environ. Exp. Bot.62, 129–138. 10.1016/j.envexpbot.2007.07.011
218
ZhengY.XuX.LiZ.YangX.ZhangC.LiF.et al. (2009). Differential responses of grain yield and quality to salinity between contrasting winter wheat cultivars. Seed Sci. Biotechnol.3, 40–43.
219
ZhouY.LiY.QiX.LiuR.DongJ.JingW.et al. (2020). Overexpression of V-type H+ pyrophosphatase gene EdVP1 from Elymus dahuricus increases yield and potassium uptake of transgenic wheat under low potassium conditions. Sci. Rep.10:5020. 10.1038/s41598-020-62052-5
220
ZhuJ.KhanK. (2001). Effects of genotype and environment on glutenin polymers and breadmaking quality. Cereal Chem.78, 125–130. 10.1094/CCHEM.2001.78.2.125
Summary
Keywords
salinity stress, antioxidant defense, wheat, stress tolerance, physiological and biochemical mechanisms
Citation
EL Sabagh A, Islam MS, Skalicky M, Ali Raza M, Singh K, Anwar Hossain M, Hossain A, Mahboob W, Iqbal MA, Ratnasekera D, Singhal RK, Ahmed S, Kumari A, Wasaya A, Sytar O, Brestic M, ÇIG F, Erman M, Habib Ur Rahman M, Ullah N and Arshad A (2021) Salinity Stress in Wheat (Triticum aestivum L.) in the Changing Climate: Adaptation and Management Strategies. Front. Agron. 3:661932. doi: 10.3389/fagro.2021.661932
Received
31 January 2021
Accepted
27 May 2021
Published
08 July 2021
Volume
3 - 2021
Edited by
Hamid Khazaei, University of Saskatchewan, Canada
Reviewed by
Ahmad Arzani, Isfahan University of Technology, Iran; Farid Shekari, University of Zanjan, Iran
Updates

Check for updates
Copyright
© 2021 EL Sabagh, Islam, Skalicky, Ali Raza, Singh, Anwar Hossain, Hossain, Mahboob, Iqbal, Ratnasekera, Singhal, Ahmed, Kumari, Wasaya, Sytar, Brestic, ÇIG, Erman, Habib Ur Rahman, Ullah and Arshad.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Ayman EL Sabagh ayman.elsabagh@agr.kfs.edu.eg
This article was submitted to Plant-Soil Interactions, a section of the journal Frontiers in Agronomy
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.