Mitigate Salinity Stress Research Articles

Synergistic N2-fixation and salt stress mitigation in soybean through dual inoculation of ACC deaminase-producing Pseudomonas and Bradyrhizobium

We investigated the potential dual application of two Bradyrhizobium strains (B. diazoefficiens USDA110 and B. ottawaense SG09) and plant growth-promoting bacteria, PGPB (Pseudomonas spp.: OFT2 and OFT5), to improve nodulation and N2-fixation in soybean plants. The growth-promoting effects of dual inoculation were observed on plant growth, physiology, and nodulation of soybean under normal conditions compared with plants individually inoculated with either USDA110 or SG09. Both OFT2 and OFT5 promoted N2-fixation by 11% and 56%, respectively, when dual inoculation with USDA110 and by 76% and 81%, respectively, when dual inoculation with SG09. Salinity stress significantly reduces soybean growth, physiology, nutrient uptake, nodulation, and N2-fixation. However, these adverse effects were attenuated by the dual inoculation of PGPB and rhizobia depending on the combination of inoculants. In particular, dual inoculation of PGPB with SG09 was more effective in enhancing the salt tolerance of soybean by reducing salt-induced ethylene production and improving nutrient uptake. However, no such effect was observed with the combined inoculation of USDA110 and OFT5. An effective symbiotic association between SG09 and two Pseudomonas bacteria can be considered a beneficial approach to improving the symbiotic efficiency of nodulation and mitigating salinity stress in soybeans.

Mitigating Salinity Stress and Improving Cotton Productivity with Agronomic Practices

In saline and salinity-affected soils, the global productivity and sustainability of cotton are severely affected by soil salinity. High salt concentrations hinder plant growth and yield formation mainly through the occurrence of osmotic stress, specific ion toxicity, and nutritional imbalance in cotton. A number of agronomic practices have been identified as potential solutions to alleviate the adverse effects induced by salinity. While genetic breeding holds promise in enhancing the salinity tolerance of cotton, agronomic practices that improve the root zone environment, ameliorate soil conditions, and enhance salinity tolerance are currently considered to be more practical. This compressive review highlights the effectiveness of agronomic practices, such as furrow seeding, plastic mulching, their combination, densely planting, and the appropriate application of fertilizer and plant growth regulators, in mitigating the negative impact of salinity on cotton. By implementing these agronomic practices, cotton growers can improve the overall performance and resilience of cotton crops in saline and salinity-affected soils. This review provides valuable insights into practical agronomic measures that can be adopted to counteract the adverse consequences of soil salinity on cotton cultivation.

Exploring the potential of halotolerant bacteria from coastal regions to mitigate salinity stress in wheat: physiological, molecular, and biochemical insights.

Salinity stress, a significant global abiotic stress, is caused by various factors such as irrigation with saline water, fertilizer overuse, and drought conditions, resulting in reduced agricultural production and sustainability. In this study, we investigated the use of halotolerant bacteria from coastal regions characterized by high salinity as a solution to address the major environmental challenge of salinity stress. To identify effective microbial strains, we isolated and characterized 81 halophilic bacteria from various sources, such as plants, rhizosphere, algae, lichen, sea sediments, and sea water. We screened these bacterial strains for their plant growth-promoting activities, such as indole acetic acid (IAA), phosphate solubilization, and siderophore production. Similarly, the evaluation of bacterial isolates through bioassay revealed that approximately 22% of the endophytic isolates and 14% of rhizospheric isolates exhibited a favorable influence on seed germination and seedling growth. Among the tested isolates, GREB3, GRRB3, and SPSB2 displayed a significant improvement in all growth parameters compared to the control. As a result, these three isolates were utilized to evaluate their efficacy in alleviating the negative impacts of salt stress (150 mM, 300 mM, and seawater (SW)) on the growth of wheat plants. The result showed that shoot length significantly increased in plants inoculated with bacterial isolates up to 15% (GREB3), 16% (GRRB3), and 24% (SPSB2), respectively, compared to the control. The SPSB2 strain was particularly effective in promoting plant growth and alleviating salt stress. All the isolates exhibited a more promotory effect on root length than shoot length. Under salt stress conditions, the GRRB3 strain significantly impacted root length, leading to a boost of up to 6%, 5%, and 3.8% at 150 mM, 300 mM, and seawater stress levels, respectively. The bacterial isolates also positively impacted the plant's secondary metabolites and antioxidant enzymes. The study also identified the WDREB2 gene as highly upregulated under salt stress, whereas DREB6 was downregulated. These findings demonstrate the potential of beneficial microbes as a sustainable approach to mitigate salinity stress in agriculture.

How Does Zinc Improve Salinity Tolerance? Mechanisms and Future Prospects.

Salinity stress (SS) is a serious abiotic stress and a major constraint to agricultural productivity across the globe. High SS negatively affects plant growth and yield by altering soil physio-chemical properties and plant physiological, biochemical, and molecular processes. The application of micronutrients is considered an important practice to mitigate the adverse effects of SS. Zinc (Zn) is an important nutrient that plays an imperative role in plant growth, and it could also help alleviate the effects of salt stress. Zn application improves seed germination, seedling growth, water uptake, plant water relations, nutrient uptake, and nutrient homeostasis, therefore improving plant performance and saline conditions. Zn application also protects the photosynthetic apparatus from salinity-induced oxidative stress and improves stomata movement, chlorophyll synthesis, carbon fixation, and osmolytes and hormone accumulation. Moreover, Zn application also increases the synthesis of secondary metabolites and the expression of stress responsive genes and stimulates antioxidant activities to counter the toxic effects of salt stress. Therefore, to better understand the role of Zn in plants under SS, we have discussed the various mechanisms by which Zn induces salinity tolerance in plants. We have also identified diverse research gaps that must be filled in future research programs. The present review article will fill the knowledge gaps on the role of Zn in mitigating salinity stress. This review will also help readers to learn more about the role of Zn and will provide new suggestions on how this knowledge can be used to develop salt tolerance in plants by using Zn.

Mitigation of Salinity Stress by Application of Plant Growth Promoting Substances in Rice

Aim: Salt stress adversely affects plant growth and development. Various mitigating strategies have been employed to enhance the adaptability of plants to salt stress. The present study was conducted with the objective of evaluating the recently developed CO55 rice variety's ability to withstand salt-induced stress during seedling growth. This evaluation included foliar spraying of plant growth promoting substances like melatonin, salicylic acid, silicon, and selenium, along with the identification of effective plant growth-promoting substances that exhibit tolerance to salinity. This study is required to develop salt-tolerant varieties capable of withstanding salinity stress during the seedling stage. The seedling stage is more susceptible to salinity, and also to increase the growth and yield of rice, thereby satisfying the country's agricultural needs.
 Study Design: Completely randomized design.
 Place and Duration of Study: Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore; March-April 2023.
 Methodology: In the hydroponics experiment, the CO55 rice variety was subjected to foliar spraying of various plant growth promoting substances such as melatonin, salicylic acid, orthosilicic acid, and sodium selenate. Parameters like leaf drying score, osmotic potential, osmotic adjustment, sodium content, potassium content, and Na+/K+ ratio were assessed. One-way ANOVA was used to analyze the data.
 Results: Specific pairwise differences between means were assessed at the 0.05 significance level using Fisher's least significant difference (LSD) test. Among the treatments applied, salicylic acid recorded the highest potassium content (3.94%), and the lowest potassium content (2.60%) was found in orthosilicic acid. On the other hand, from the standard evaluation score, it was observed that CO55 rice variety seedlings were found to be tolerant when treated with salicylic acid, whereas it was susceptible under orthosilicic acid treatment.
 Conclusion: Observations indicated that foliar application of salicylic acid at the concentrations of 50µM and 100µM exhibited higher tolerance towards salinity during the seedling growth stages.

Improvement of physio-biochemical attributes and mitigation of salinity stress by combined application of melatonin and silicon nanoparticles in Brassica oleracea var. botrytis

Salinity is a significant abiotic stress in arid and semiarid areas, threatening global food security. This research explored the potential of silicon nanoparticles (Si-NPs) and Melatonin (MT) to alleviate salinity stress in Brassica oleracea var. botrytis. The study used varying Si-NPs concentrations viz. NP0 (distilled water), NP1 (50 mg/L), NP2 (100 mg/L), and NP3 (200 mg/L) and Melatonin following a completely randomized design (CRD). Salinity hindered the growth and phytochemical attributes of B. oleracea seedlings. However, applying Si-NPs and MT mitigated this stress. Maximum fresh root weight of seedlings was observed when seeds were primed with 80 mg/L Si-NPs under 200 mM salt concentration, and the highest root length was noted with 60 mg/L and 80 mg/L Si-NPs. Seeds primed with 40 and 80 mg/L Si-NPs displayed the highest leaf count in seedlings under 50- and 100-mM salt concentrations, respectively. At 200 mM salt concentration, 40 mg/L and 60 mg/L Si-NPs priming notably enhanced total chlorophyll contents. Relative chlorophyll contents significantly increased with Si-NPs priming of 40 mg/L, 60 mg/L, and 80 mg/L under varying salt solutions along with melatonin. Exposure to 200 mM Si-NPs led to enhanced superoxide dismutase production in plants compared to control. Si-NPs and MT supplementation notably elevated osmolyte levels in salt-stressed B. oleracea seedlings compared to other treatments. Hence, treatment of Si-NPs and MT might be effective against abiotic stress in B. oleracea. This study offers valuable insights for cultivating economically important crops in high salt-stressed agricultural lands.

Selection of Salinity-Adapted Endorhizal Fungal Consortia from Two Inoculum Sources and Six Halophyte Plants.

Soil salinity is a limiting factor in crop productivity. Inoculating crops with microorganisms adapted to salt stress is an alternative to increasing plant salinity tolerance. Few studies have simultaneously propagated arbuscular mycorrhizal fungi (AMF) and dark septate fungi (DSF) using different sources of native inoculum from halophyte plants and evaluated their effectiveness. In alfalfa plants as trap culture, this study assessed the infectivity of 38 microbial consortia native from rhizosphere soil (19) or roots (19) from six halophyte plants, as well as their effectiveness in mitigating salinity stress. Inoculation with soil resulted in 26-56% colonization by AMF and 12-32% by DSF. Root inoculation produced 10-56% and 8-24% colonization by AMF and DSF, respectively. There was no difference in the number of spores of AMF produced with both inoculum types. The effective consortia were selected based on low Na but high P and K shoot concentrations that are variable and are relevant for plant nutrition and salt stress mitigation. This microbial consortia selection may be a novel and applicable model, which would allow the production of native microbial inoculants adapted to salinity to diminish the harmful effects of salinity stress in glycophyte plants in the context of sustainable agriculture.

Enhancing maize growth and mitigating salinity stress through foliar application of proline and glycine betaine

Enhancing maize growth and mitigating salinity stress through foliar application of proline and glycine betaine

Effect of Biochar and Compost Addition on Mitigating Salinity Stress and Improving Fruit Quality of Tomato

To overcome food security, sustainable strategies for reclamation and the subsequent utilization of salt-affected soils for crop production are needed. The aim of the current study was to evaluate the impacts of compost and biochar addition on the growth and fruit quality of tomato under salinity stress. For this purpose, the soil was spiked with analytical grade sodium chloride to achieve a 6 dS m−1 salinity level for a pot experiment. After 30 days of spiking, the compost (2%) and biochar (2%) were added in selected pots. After the seedling transplant, recommended doses of NPK were added to fulfill nutrient requirements of tomato plants. Plants were harvested after 90 days of seedling transplantation. Results revealed that the salinity caused a significant reduction of 28.4% in SPAD value, 23.5% in Ft, 22.6% in MSI, 12.1% in RWC, 18.3% in Chl. a, 13.7% in Chl. b, and 16.5% in T. Chl. as compared to the un-amended non-saline control in physiological attributes of tomato plants. Similarly, a significant decrease of 26.9–44.1% was obtained in growth attributes of tomato as compared to the non-saline control. However, in saline soil, the addition of biochar and compost (alone or together) demonstrated a significant improvement in plant growth (i.e., up 45%) over the respective un-amended control. Moreover, the combined application of compost and biochar significantly reduced the sodium (Na+) in shoots and roots of tomato plants by 40% and 47%, respectively, over the respective control. Our findings suggest that the combined application of biochar and compost could be useful to reduce salinity, alleviate salinity-induced phytotoxicity, and subsequently improve plant growth and productivity in salt-affected soil.

Biochar improves the growth and physiological traits of alfalfa, amaranth and maize grown under salt stress.

Salinity is a main factor in decreasing seed germination, plant growth and yield. Salinity stress is a major problem for economic crops, as it can reduce crop yields and quality. Salinity stress occurs when the soil or water in which a crop is grown has a high salt content. Biochar improve plant growth and physiological traits under salt stress. The aim of the present study, the impact of biochar on growth, root morphological traits and physiological properties of alfalfa, amaranth and maize and soil enzyme activities under saline sands. We studied the impact of biochar on plant growth and the physiological properties of alfalfa, amaranth and maize under salt stress conditions. After 40 days, plant growth parameters (plant height, shoot and root fresh weights), root morphological traits and physiological properties were measured. Soil nutrients such as the P, K and total N contents in soil and soil enzyme activities were analyzed. The results showed that the maize, alfalfa, and amaranth under biochar treatments significantly enhanced the plant height and root morphological traits over the control. The biochar on significantly increased the total root length, root diameter, and root volume. Compared to the control, the biochar significantly increased the chlorophyll a and b content, total chlorophyll and carotenoid content under salt stress. Furthermore, the biochar significantly increased enzyme activities of soil under salt stress in the three crops. Biochar treatments promote plant growth and physiological traits of alfalfa, amaranth, and maize under the salt stress condition. Overall, biochar is an effective way to mitigate salinity stress in crops. It can help to reduce the amount of salt in the soil, improve the soil structure, and increase the availability of essential nutrients, which can all help to improve crop yields.

Zinc oxide nanoparticles: A unique saline stress mitigator with the potential to increase future crop production

Globally, soil salinity is an abiotic stress that can threaten arable lands and crop production and consequently can negatively affect food security. Therefore, the aim of this review was to study the utilizing zinc oxide nanoparticles (ZnO-NPs) as a novel approach to mitigate salinity stress and its negative impacts on environment and crop productivity. The application of ZnO-NPs can significantly enhance plant growth, physiological and metabolic activity, and yield as well as crop quality. The antioxidant enzymes activities such as superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) are increased when ZnO-NPs are applied which can mitigate the damage caused by ROS species and make them a valuable tool for future agriculture. The sucrose synthesis which ultimately biosynthesizes lipopolysaccharides (LP), glycinebetaine (GB), and total soluble protein (TSP), and enhanced ribulose bisphosphate carboxylase-oxygenase activity, light-capturing efficiency of photosystem II, as well as the ability to transport electrons under salinity stress are increased by the application of ZnO-NPs. Therefore, ZnO-NPs can be used as a potential strategy for promoting precision agriculture. The existing yield gap under a saline environment can be minimized by promoting the application of ZnO-NPs as it serves as a cheap, environment-friendly, and efficient source of Zn. In a nutshell, being an efficient and eco-friendly nanomaterial ZnO-NPs play a key role in mitigating saline stress by alleviating NaCl toxicity and enhancing crop productivity in saline soils.

Physiological and Molecular Analysis Revealed the Role of Silicon in Modulating Salinity Stress in Mung Bean

Salinity stress acts as a significant deterrent in the course of optimal plant growth and productivity, and mung bean, being a relay crop in the cereal cropping system, is severely affected by salinity. Silicon (Si), on the other hand, has exhibited promising outcomes with regards to alleviating salinity stress. In order to understand the critical mechanisms underlying mung bean (Vigna radiata L.) tolerance towards salt stress, this study examined the effects of different salinity concentrations on antioxidant capacity, proteome level alterations, and influence on Si-transporter and salt-responsive genes. Salinity stress was seen to effect the gaseous exchange machinery, decrease the soluble protein and phenolic content and NR activity, and increase the accumulation of reactive oxygen species. An efficient regulation of stomatal opening upon Si application hints towards proficient stomatal conductance and CO2 fixation, resulting in efficient photosynthesis leading to proficient plant growth. The soluble protein and phenolic content showed improved levels upon Si supplementation, which indicates an optimal solute transport system from source to sink. The content of superoxide radicals showed a surge under salinity stress treatment, but efficient scavenging of superoxide radicles was noted under Si supplementation. Salinity stress exhibited more damaging effects on root NR activity, which was notably enhanced upon Si supplementation. Moreover, the beneficial role of Si was further substantiated as there was notable Si accumulation in the leaves and roots of salinity-stressed mung bean plants. Furthermore, Si stimulated competent ROS scavenging by reinforcing the antioxidant enzyme activity, as well coordinating with their isozyme activity, as expressed by the varying band intensities. Similarly, the Si-mediated increase in peroxidase activity may reveal changes in the mechanical characteristics of the cell wall, which are in turn associated with salinity stress adaptation. Proteomic investigations revealed the upregulation or downregulation of several proteins, which were thereafter identified by LC−MS/MS. About 45 proteins were identified and were functionally classified into photosynthesis (24%), metabolic process (19%), redox homeostasis (12%), transmembrane transport (10%), stress response (7%), and transcription regulation (4%). The gene expression analysis of the silicon transporter genes (Lsi1, Lsi2, and Lsi3) and SOS pathway genes (SOS1, SOS2, and SOS3) indicated the role of silicon in mitigating salinity stress. Hence, the findings of this study can facilitate a profound understanding of the potential mechanisms adopted by mung bean due to exogenous Si application during salinity stress.

Ameliorative effect of micro-algal and medicinal plants on some biochemical properties of bean plants under salinity stress

This study was conducted to examine the ameliorative effects of foliar application of some micro-algal (Chlorella vulgaris and Spirulina platensis) and some medicinal plant leaves (Salix alba, Psidium guajava, and Olea europaea) extracts on Phaseolus vulgaris (Bean) under salinity stress. On a loamy soil, a pots trial was carried out on bean plants grown under salinity stress. Growth characteristics, pigments, osmolytes, total phenol, and antioxidant enzyme contents were determined. S. platensis extract application showed the greatest improvement in shoot length and fresh weight of shoot, which rose 23.5% and 65.1%, respectively compared to the control. The utilized bio-stimulants, particularly S. platensis extracts, remarkably increased the chlorophyll content compared to the control under salinity stress. The photosynthetic pigment, soluble sugars, and soluble protein levels were strengthened by foliar application of bio-stimulant extract. Proline and antioxidant enzyme levels are significantly reduced using algal and plant extracts treatment. These findings support the treatment’s increased contribution to reducing salt stress and their detrimental effects on bean plants.The findings of this study indicate that the use of these biostimulants, especially S. alba, P. guajava, and O. europaea leaf extracts can be considered as an unconventional, ecofriendly, and novel tool in the mitigation of salinity stress.

Exogenous application of sodium hydrosulfide and salicylic acid mitigate salinity stress in maize by regulating ionic balance, biochemical attributes, photosynthetic pigments and some key antioxidants

Hydrogen sulfide (H2S) and salicylic acid (SA) have been recently explored as important priming agents for plant growth and development. The effects of NaHS alone and in combination with SA to alleviate salt stress effects on maize plants are not determined yet. Here, we executed an approach to examine the effects of NaHS (H2S donor) and SA treatments to overcome the salt stress in maize plants. In vitro screening exhibited that SA (0.1 mM) and NaHS (0.5 mM) as the most effective concentrations to increase biomass and germination of maize plant under salt stress. Furthermore, data revealed that alone and combined treatments of H2S and SA during salt stress showed improved morphological, biochemical, and physiological attributes compared to non-treated plants. However, combined treated plants exhibited maximum salinity resistance than individual treatments. The combined treatment showed increased chlorophyll a (165%), chlorophyll b (138%) and carotenoid (54.4%) and increased activities of antioxidants enzymes like catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and polyphenol oxidase (PPO) by 441%, 416.7%, 501.4% and 510%, respectively while reduced Na+accumulation and enhanced K+accumulation. Combined treatment protects the plants by lowering proline and MDA content by 300% and 108% respectively. Our in-silico outcomes of the NaHS-SA pathway verify experimental results regarding modulation of salt stress response mechanisms depicts ideal picture of above-mentioned parameters during stress hence suggesting NaHS-SA mediated biofertilizers could strengthen genomic stability and maintenance capability under stress.

Salicylic Acid and Pyraclostrobin Can Mitigate Salinity Stress and Improve Anti-Oxidative Enzyme Activities, Photosynthesis, and Soybean Production under Saline–Alkali Regions

Soybean is a widespread crop in semi-arid regions of China, where soil salinity often increases and has a significant harmful impact on production, which will be a huge challenge in the coming years. Salicylic acid (SA) and pyraclostrobin are strobilurin-based bactericides (PBF). Under rainfall-harvesting conditions in covered ridges, the exogenous application of SA and PBF can improve the growth performance of soybeans, thereby reducing the adverse effects of soil salinity. The objectives of this research are to evaluate the potential effects of SA and PBF on soybean growth in two different regions, Harbin and Daqing. A two-year study was performed with the following four treatments: HCK: Harbin location with control; SA1+PBF1: salicylic acid (5 mL L−1) with pyraclostrobin (3 mL L−1); SA2+PBF2: salicylic acid (10 mL L−1) with pyraclostrobin (6 mL L−1); DCK: Daqing location with control. The results showed that in the Harbin region, SA2+PBF2 treatment reduced the evapotranspiration (ET) rate, increased soil water storage (SWS) during branching and flowering stages, and achieved a maximum photosynthesis rate. Moreover, this improvement is due to the reduction of MDA and oxidative damage in soybean at various growth stages. At different growth stages, the treatment of Harbin soybean with SA2+PBF2 significantly increased the activity of CAT, POD, SOD, and SP, while the content of MDA, H2O2, and O2− also decreased significantly. In the treatment of SA2+PBF2 in Harbin, the scavenging ability of free H2O2 and O2− was higher, and the activity of antioxidant enzymes was better. This was due to a worse level of lipid-peroxidation which successfully protected the photosynthesis mechanism and considerably increased water use efficiency (WUE) (46.3%) and grain yield (57.5%). Therefore, using plastic mulch with SA2+PBF2 treatment can be an effective water-saving management strategy, improving anti-oxidant enzyme activities, photosynthesis, and soybean production.

Impact of Salicylic and Jasmonic Acid in Mitigating Salinity Stress on Date Palm Phoenix dactylifera L. Barhi Cv.

Date palm is one of the most important trees for economic and social development in many countries and its fruits with high nutritional value. This aimed to determine the role of salicylic (SA) and jasmonic acids (JA) as antioxidants against salt stress. Salt stress was applied with water irrigation to two-year-old date palm offshoots by using 200 mM NaCl alone or in combination with foliar sprays of JA and SA at 1, 2 and 3 mgL-1. Results indicate that salinity at 200 mM NaCl remarkably increased the content of osmolytes (e.g., proline, glycine betaine and soluble sugars) in date palm leaves. Moreover, with the combination of 2 and 3 mg.L-1 SA and 1 mg.L-1 JA with salinity, the osmolyte content was remarkably higher than in salinity treatment alone. When date palm was exposed to salinity alone, the levels of oxidative markers, Malondialdehyde as a lipid peroxidation marker and H2O2 as a ROS accumulation marker, substantially increased compared with the control. Importantly, the levels of these oxidative markers remarkably decreased when plants were subjected to combined salinity and treatment with at 2 and 3 mg.L-1 SA and 3 mg.L-1 SA compared with the salinity treatment alone. In addition, spraying 2 and 3 mg.L-1 SA and 3 mg.L-1 JA on leaves combined with salinity treatment remarkably decreased the salinity effect on membrane stability index. Moreover, when 2 or 3 mg.L-1 were sprayed, no remarkable difference was detected for any investigated characteristics, and SA had a greater effect than JA in alleviating the salinity effect.

Effects of Slag Applications and Salinity Stress on Greenhouse Durum Wheat (Triticum durum Desf.) Plants

The search for sustainable practices to increase productivity is a fundamental need in current agriculture. Steel slag has been studied for its potential use in agriculture. These substances present a great ability of agricultural applications since they are rich in nutrients. The effect of steel slag-based fertilizer was investigated on greenhouse durum wheat cultivar under salt-stress conditions. Two doses of slag: 10 g slag/ kg soil (D1) and 20 g slag/ kg soil (D2) were evaluated under no salt-stress (0 mM NaCl) and salt-stress conditions (100 mM NaCl) for salinity stress mitigation. Morpho-physiological and biochemical parameters of wheat were measured and compared to the different treatments. Exposure of wheat to salinity decreased its biomass, stomatal conductance, efficiency of photosystem II, and protein content, but it increased total soluble sugars, hydrogen peroxide (H2O2), and malondialdehyde (MDA) contents. Amended plants with 10 g slag/ kg soil (D1) led to a significant improvement in biomass with an increase of shoot and root dry weights (133% and 400% respectively), stomatal conductance (22 %), soluble sugars (14 %), and protein content (158%) under saline conditions compared to the control treatment with 0 g slag/ kg soil (C), thus indicating a positive influence on durum wheat plants. Soil enrichment with 20 g slag/kg soil (D2) decreased plant growth parameters and presented the highest levels of H2O2 and MDA contents compared to the control and treatment (D1) after three months of cultivation under salt stress. This study supports the hypothesis of the application of slag at lower dose, which improves productivity of durum wheat and mitigate salinity stress.

Exogenous application of spermidine and methyl jasmonate can mitigate salt stress in fenugreek (Trigonella foenum-graecum L.)

Fenugreek (Trigonella foenum-graecum L.) has long been cultivated as both culinary and medicinal plant. The objective of this study was to investigate the effect of plant growth regulators such as spermidine (Spd) and methyl jasmonate (MeJA) on morpho-physiological and biochemical properties of fenugreek under saline conditions. A replicated greenhouse experiment in completely randomized block design was conducted with two levels of salinity (0.5 dS/m as control and 6 dS/m), three levels of spermidine (0, 1, 2 mM) and methyl jasmonate (0, 100, 200 µM), respectively. The results showed that salinity elevation reduced the leaf relative water content, leaf water potential, canopy-air temperature difference, photochemistry efficiency of photosystem II, and water-use efficiency of fenugreek. In contrast, salinity increased leaf thickness,greenness index, canopy temperature, leaf Na+, ash contents, malondialdehyde, other aldehydes, and electrolyte leakage. Moreover, Salinity stress reduced the amount of photosynthetic pigments, chlorophyll a/b ratio, total soluble protein, K+, maximum fluorescence, and K+/Na+ ratio in leaves. Elevation of water salinity, however, resulted in an increase in the activity of antioxidant enzymes (except superoxide dismutase), proline, and minimum fluorescence. When fenugreek was treated with 1 mM spermidine and/or 100 µM methyl jasmonate, the adverse effects of salinity stress were significantly mitigated, while the effects of these plant growth regulators on mitigating salinity stress were less pronounced at higher concentrations (2 mM spermidine and/or 200 µM methyl jasmonate). The current study suggests the application of 1 mM spermidine and/or 100 µM methyl jasmonate during the vegetative growth stage mitigating the adverse effects of salinity with an associated improvement in plant growth under moderate salinity (about 6 dS/m) when used for irrigation.

Scaling the invisible wall: Molecular acclimation of a salinity-tolerant diatom to freshwater.

In aquatic ecosystems, marine and freshwater environments are separated by steep salinity gradients. The osmotic stress induced by this 'invisible wall' forms an insurmountable barrier for many aquatic lifeforms, including bacteria, algae and animals. Because the osmotic differences when transiting a salinity divide are so hard to overcome, most species have adapted exclusively to a marine or a freshwater lifestyle. A major consequence of this physiological specialization into marine and freshwater organisms is that transitions are relatively rare, impeding regular contact and colonization. While some animals use specialized organs or behaviour to cope with unfavourable salinity levels, unicellular algae such as diatoms are completely dependent on cellular mechanisms to mitigate salinity stress. In this issue of Molecular Ecology, Downey and colleagues investigate the transcriptomic response of a salinity-tolerant diatom to a shock treatment with freshwater (Molecular Ecology, 2023). Through frequent sampling and integration of existing RNA sequencing data, a fine-grained model of the acclimation to hypo-osmotic stress emerges. Deciphering the pathways that drive the acute and long-term acclimation to freshwater has major implications for diatom ecology, diversification and resilience to global change.

Interplay between membrane proteins and membrane protein-lipid pertaining to plant salinity stress.

High salinity in agricultural lands is one of the predominant issues limiting agricultural yields. Plants have developed several mechanisms to withstand salinity stress, but the mechanisms are not effective enough for most crops to prevent and persist the salinity stress. Plant salt tolerance pathways involve membrane proteins that have a crucial role in sensing and mitigating salinity stress. Due to a strategic location interfacing two distinct cellular environments, membrane proteins can be considered checkpoints to the salt tolerance pathways in plants. Related membrane proteins functions include ion homeostasis, osmosensing or ion sensing, signal transduction, redox homeostasis, and small molecule transport. Therefore, modulating plant membrane proteins' function, expression, and distribution can improve plant salt tolerance. This review discusses the membrane protein-protein and protein-lipid interactions related to plant salinity stress. It will also highlight the finding of membrane protein-lipid interactions from the context of recent structural evidence. Finally, the importance of membrane protein-protein and protein-lipid interaction is discussed, and a future perspective on studying the membrane protein-protein and protein-lipid interactions to develop strategies for improving salinity tolerance is proposed.