Adverse Effects Of Salinity Stress Research Articles

Enhancing salinity stress tolerance in corn salad (Valerianella locusta L.) through melatonin or salicylic acid-functionalized chitosan seed priming: A smart delivery approach

Soil salinity represents a significant environmental stressor that impairs crop production and yield. A wide range of treatments have been used to reduce the effects of salinity in plants. Among the treatments used, functionalized nanoparticles (NPs) have shown great results. In light of recently demonstrated beneficial effects of chitosan-melatonin nanoparticles (CTS-Mel NPs) and chitosan-salicylic acid nanoparticles (CTS-SA NPs) in mitigating the deleterious consequences of major stress factors and boosting secondary metabolite biosynthesis, the current study aimed to investigate their potential as seed priming coatings to enhance plant performance under both control and salinity stress conditions. For this purpose, CTS (0.1% w/v), Mel (50 µM), SA (0.5 mM), CTS-Mel NPs and CTS-SA NPs were applied as seed priming agents on corn salad (Valerianella locusta) seeds, and subsequently key morphophysiological and biochemical properties were assayed under salinity conditions (0, 30 and 60 mM NaCl). Accordingly, salinity stress caused significant reduction in fresh and dry weights (FW and DW) of leaves, chl a, total chl, SPAD and enhancement in content of proline, phenolics, MDA, as well as protein content, and activities of SOD and CAT antioxidant enzymes. Concerning the phenolic compounds analyzed, salinity stress did not affect the dominant phenolic constituents with the exception of naringine. Regarding the protective effects of the various priming treatments, the adverse effects of salinity stress were ameliorated with the application of most of the applied treatments, and with CTS-Mel NPs in particular, by enhancing biomass, pigments, total phenols, protein, SOD and CAT antioxidant enzymatic activities, as well as the content of some dominant constituents of phenolic profile. CTS-Mel NPs enhanced chlorogenic acid, naringine, o-coumaric acid and catechin hydrate under both control and salinity conditions. Overall, CTS-Mel NPs outperformed CTS-SA NPs as a seed priming coating and could potentially be widely introduced as an innovative, sustainable approach to mitigate the effects of salinity and other abiotic stress conditions in crop plants.

Role of Arbuscular Mycorrhizal Fungi in Alleviating Salinity Stress and Improving Physiological Parameters of Wheat (Triticum aestivum L.): A Review

Salinity stress poses a significant threat to global wheat production, impacting crop yield and food security. In recent years, Arbuscular Mycorrhizal Fungi (AMF) have gained attention as potential bioinoculants capable of mitigating salinity-induced stress and improving plant physiological parameters. This review provides a comprehensive examination of the role of AMF in alleviating salinity stress and enhancing physiological parameters in wheat (Triticum aestivum L.). Through a systematic analysis of relevant literature, we explore the mechanisms underlying the beneficial interactions between AMF and wheat under saline conditions. Key findings from various studies demonstrate that AMF colonization enhances wheat growth, nutrient uptake, and antioxidant enzyme activities, while reducing the adverse effects of salinity stress. However, challenges such as variability in AMF effectiveness and compatibility with modern agricultural practices persist. Future research directions should focus on refining AMF inoculation techniques and developing strains with enhanced salt tolerance to maximize their potential in sustainable agriculture. Overall, this review underscores the promising role of AMF in revolutionizing wheat cultivation in saline environments, offering insights for enhancing crop productivity and resilience to salinity stress.

Role of iron oxide nanoparticles in maize (Zea mays L.) to enhance salinity stress tolerance

Soils have been getting worse over time, which has led to lower crop yields and nutritional value. This is because of too many conventional fertilizers, anthropogenic activities, and climate change. Soil salinity is also a big problem and challenge for agricultural scientists. To address this issue, nanoparticles are gaining a reputation in agriculture that can enhance salinity tolerance in crops, especially at early growth stages. A pot experiment was conducted at Post Agricultural Research Station (PARS), Faisalabad to assess the impact of iron oxide nanoparticles (0, 15, and 30 ppm) and four levels of salinity (0, 50, 100 and 150 mM) on morphological, physiological and yield traits of maize (Zea mays L.) in salinity stress. Salinity stress significantly negatively affected the growth attributes, photosynthetic pigments, ion content (Na+, K+, and Ca2+) of maize plants. Salinity has also increased the levels of MDA, H2O2, and Na+ ions. The application of iron oxide nanoparticles through foliar spray had a notable impact in enhancing the growth and yield of the tested maize variety. It was achieved by promoting the activities of antioxidant enzymes, increasing photosynthetic pigments, and elevating K+ and Ca2+ ion levels under both normal and salinity-stressed conditions. Additionally, iron oxide nanoparticles mitigated the adverse effects of salinity stress by effectively reducing Na+ ion concentration, MDA levels, and H2O2 concentration. Among the different concentrations tested, 30 ppm of iron oxide nanoparticles proved best in alleviating the negative impacts of salinity stress in maize. Thus, field use of 30 ppm iron oxide nanoparticles as foliar spray could effectively mitigate salinity stress in maize.

Mitigation of salinity stress in yarrow (Achillea millefolium L.) plants through spermidine application.

This study investigated the mitigating effects of spermidine on salinity-stressed yarrow plants (Achillea millefolium L.), an economically important medicinal crop. Plants were treated with four salinity levels (0, 30, 60, 90 mM NaCl) and three spermidine concentrations (0, 1.5, 3 μM). Salinity induced electrolyte leakage in a dose-dependent manner, increasing from 22% at 30 mM to 56% at 90 mM NaCl without spermidine. However, 1.5 μM spermidine significantly reduced leakage across salinities by 1.35-11.2% relative to untreated stressed plants. Photosynthetic pigments (chlorophyll a, b, carotenoids) also exhibited salinity- and spermidine-modulated responses. While salinity decreased chlorophyll a, both spermidine concentrations increased chlorophyll b and carotenoids under most saline conditions. Salinity and spermidine synergistically elevated osmoprotectants proline and total carbohydrates, with 3 μM spermidine augmenting proline and carbohydrates up to 14.4% and 13.1% at 90 mM NaCl, respectively. Antioxidant enzymes CAT, POD and APX displayed complex regulation influenced by treatment factors. Moreover, salinity stress and spermidine also influenced the expression of linalool and pinene synthetase genes, with the highest expression levels observed under 90 mM salt stress and the application of 3 μM spermidine. The findings provide valuable insights into the responses of yarrow plants to salinity stress and highlight the potential of spermidine in mitigating the adverse effects of salinity stress.

A REVIEW ON IMPROVEMENT OF SALT TOLERANCE IN RICE (ORYZA SATIVA L) BY INCREASING ANTIOXIDANT DEFENCE SYSTEMS USING EXOGENOUS APPLICATION OF PROLINE

Rice (Oryza sativa L) stands as a staple food crop globally particularly in the regions with warm climates. However, its cultivation faces significant challenges from abiotic stresses like salinity, which hinder crop growth and productivity. Salinity stress disrupts essential physiological processes, leading to reduced yields and compromised food security. In response to this pressing concern, this review investigates the potential of exogenous proline application to enhance salt tolerance in rice. The study delves into the intricate mechanisms underlying salinity stress in rice plants, highlighting its detrimental effects on growth, ion balance, and cellular metabolism. Salinity-induced oxidative stress, characterized by the accumulation of reactive oxygen species (ROS), exacerbates cellular damage, impairing plant growth and development. Proline, an amino acid known for its multifaceted roles in stress mitigation, emerges as a promising candidate for enhancing salt tolerance in rice. Exogenous application of proline demonstrates significant improvements in rice growth, yield and physiological attributes under saline conditions. The study elucidates the impact of exogenous proline on various aspects of rice physiology, including seed germination, water relations, and oxidative stress mitigation. By enhancing nutrient uptake, maintaining ion homeostasis, and fortifying antioxidant defences, proline offers a promising avenue for sustainable rice production in the face of escalating salinity stress. In conclusion, this study underscores the pivotal role of exogenous proline in augmenting salt tolerance in rice, offering insights into novel strategies for mitigating the adverse effects of salinity stress on crop yields.

Response of Different Doses of Zinc Oxide Nanoparticles in Early Growth of Mung Bean Seedlings to Seed Priming under Salinity Stress Condition

Background: Salinity impacts physiological processes, including germination, seedling development, ionic balance and water relations, leading to growth inhibition. Mung bean’s early stage is susceptible to salt stress. Our study aimed to mitigate salt stress at early stage using zinc oxide nanoparticles (ZnO-NPs) to enhance mung bean tolerance. Methods: Pot experiment was carried out to incorporate ZnO-NPs into mung bean seedlings. Two Mung bean genotypes, TMB-37 (tolerant) and MH-1314 (sensitive), were chosen. Seeds were primed with ZnO-NPs at various concentrations (0.00 ppm, 50 ppm, 100 ppm, 500 ppm and 1000 ppm) and shown in saline soil. Result: ZnO-NP priming notably increased germination percentage, shoot length and shoot dry weight in both genotypes. In 25-days-old seedlings, ZnO-NPs elevated antioxidant enzyme activity, proline content, especially superoxide dismutase (SOD) and peroxidase (POX) activity, while reducing lipid peroxidation and membrane injury. 1000 ppm ZnO-NPs had the negative impact on the root trait of sensitive genotype. Lower doses of ZnO-NP (50 ppm) concentrations was very effective in mitigating the adverse effect of salinity stress in both the genotypes offering a key approach for Mung bean’s salt stress mitigation.

Investigating the growth promotion potential of biochar on pea (Pisum sativum) plants under saline conditions

Pea, member of the plant family Leguminosae, play a pivotal role in global food security as essential legumes. However, their production faces challenges stemming from the detrimental impacts of abiotic stressors, leading to a concerning decline in output. Salinity stress is one of the major factors that limiting the growth and productivity of pea. However, biochar amendment in soil has a potential role in alleviating the oxidative damage caused by salinity stress. The purpose of the study was to evaluate the potential role of biochar amendment in soil that may mitigate the adverse effect of salinity stress on pea. The treatments of this study were, (a) Pea varieties; (i) V1 = Meteor and V2 = Green Grass, Salinity Stress, (b) Control (0 mM) and (ii) Salinity (80 mM) (c) Biochar applications; (i) Control, (ii) 8 g/kg soil (56 g) and (iii) 16 g/kg soil (112 g). Salinity stress demonstrated a considerable reduction in morphological parameters as Shoot and root length decreased by (29% and 47%), fresh weight and dry weight of shoot and root by (85, 63%) and (49, 68%), as well as area of leaf reduced by (71%) among both varieties. Photosynthetic pigments (chlorophyll a, b, and carotenoid contents decreased under 80 mM salinity up to (41, 63, 55 and 76%) in both varieties as compared to control. Exposure of pea plants to salinity stress increased the oxidative damage by enhancing hydrogen peroxide and malondialdehyde content by (79 and 89%), while amendment of biochar reduced their activities as, (56% and 59%) in both varieties. The activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) were increased by biochar applications under salinity stress as, (49, 59, and 86%) as well as non-enzymatic antioxidants as, anthocyanin and flavonoids improved by (112 and 67%). Organic osmolytes such as total soluble proteins, sugars, and glycine betaine were increased up to (57, 83, and 140%) by biochar amendment. Among uptake of mineral ions, shoot and root Na+ uptake was greater (144 and 73%) in saline-stressed plants as compared to control, while shoot and root Ca2+ and K+ were greater up to (175, 119%) and (77, 146%) in biochar-treated plants. Overall findings revealed that 16 g/kg soil (112 g) biochar was found to be effective in reducing salinity toxicity by causing reduction in reactive oxygen species and root and shoot Na+ ions uptake and improving growth, physiological and anti-oxidative activities in pea plants (Fig. 1).Figure 1A schematic diagram represents two different mechanisms of pea under salinity stress (control and 80 mM NaCl) with Biochar (8 and 16 g/kg soil).

Responses of bread wheat to Zn-Glycine and Zn-Alanine fertilizers under saline soil condition

Zinc (Zn) deficiency and salt stress are well-known soil problems and often happen parallelly in cultivated soils. In this study, Zn-amino acid complexes (Zn-AAc) were used as a source of Zn to determine their effects on salt-induced damage in wheat plants. The bread wheat (Triticum aestivum L. cvs. Kavir) was supplied with Zn-glycine (Zn-Gly), Zn-alanine (Zn-Ala), and ZnSO4 as Zn sources at three salinity levels (EC 2, 4 and 6 dS m-). Salinity caused a significant decrease in shoot dry matter and grain yield of wheat, but this negative effect was significantly improved by the application of Zn-AAc. Salt stress decreased shoot and grain Zn concentration, but this reduction was lower in plants supplied by Zn-AAc. Calcium (Ca) and potassium (K) concentrations were increased in a shoot by salinity stress while decreased in grain. Sodium (Na) concentration decreased in shoot and grain by using Zn-AAc. At all of the salinity levels, wheat supplied with Zn-AAc had lower lipid peroxidation compared to those grown under the ZnSO4 source. Application of Zn-AAc increased the activities of catalase (CAT) and superoxide dismutase (SOD) in the roots of wheat plants in saline conditions. Based on the results, the adverse effects of salinity stress on wheat plants can moderately improve with Zn-AAc application.

Exogenous application of 5-azacitidin, royal jelly and folic acid regulate plant redox state, expression level of DNA methyltransferases and alleviate adverse effects of salinity stress on Vicia faba L. plants

DNA methylation is one of induced changes under salinity stress causing reduction in the expression of several crucial genes required for normal plant's operation. Potential use of royal jelly (RJ), folic acid (FA) and 5-azacitidine (5-AZA) on two Egyptian faba bean varieties (Sakha-3 and Giza-716) grown under saline conditions was investigated. Salinity stress affects negatively on seeds germination (G %), mitotic index, membrane stability and induced a significant increase in chromosomal abnormalities (CAs). DNA methyltransferases genes (MT1 and MT2) were highly up-regulated (∼23 and 8 folds for MT1 and MT2 in shoots of Giza-716 stressed plants). On the other hand, down regulation of other studied stress related genes: superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), heat shock protein (HSP-17.9) and proline-rich protein (GPRP) were detected in stressed plants of both studied varieties. Treating plants with RJ and FA increase G%, chlorophyll content, improves membrane properties and reduces CAs compared to non-treated stressed plants. Exogenous application of 5-AZA, RJ and FA on salinity stressed plants was associated with a significant reduction in the transcription of MT1 and MT2 which was associated with significant up regulation in the expression of Cu/Zn-SOD, CAT, GR, GPRP and HSP-17.9 encoding genes. The Lowest expression of MT1 and MT2 were induced with 5-AZA treatment in both studied varieties. Exogenous application of the FA, RJ and 5-AZA modified the methylation state of stressed plants by regulation the expression of DNA methyltransferases, subsequently, modulated the expression of studied genes and could be proposed as a promising treatment to ameliorate hazardous effects of salt stress on different plants.

Copper Oxide Nanoparticles Induced Growth and Physio-Biochemical Changes in Maize (Zea mays L.) in Saline Soil.

Research on nanoparticles (NPs) is gaining great attention in modulating abiotic stress tolerance and improving crop productivity. Therefore, this investigation was carried out to evaluate the effects of copper oxide nanoparticles (CuO-NPs) on growth and biochemical characteristics in two maize hybrids (YH-5427 and FH-1046) grown under normal conditions or subjected to saline stress. A pot-culture experiment was carried out in the Botanical Research Area of "the University of Lahore", Lahore, Pakistan, in a completely randomized design. At two phenological stages, both maize hybrids were irrigated with the same amount of distilled water or NaCl solution (EC = 5 dS m-1) and subjected or not to foliar treatment with a suspension of CuO-NPs. The salt stress significantly reduced the photosynthetic parameters (photosynthetic rate, transpiration, stomatal conductance), while the sodium content in the shoot and root increased. The foliar spray with CuO-NPs improved the growth and photosynthetic attributes, along with the N, P, K, Ca, and Mg content in the roots and shoots. However, the maize hybrid YH-5427 responded better than the other hybrid to the saline stress when sprayed with CuO-NPs. Overall, the findings of the current investigation demonstrated that CuO-NPs can help to reduce the adverse effects of salinity stress on maize plants by improving growth and physio-biochemical attributes.

Mitigating Salinity Stress in Pomegranate: Effects of Pseudomonas fluorescens and Glomus mosseae on Stress Responses of Red Angel and Wonderful Cultivars

Salinity stress is a major challenge in modern pomegranate orchards. The application of biofertilizers is a promising strategy to mitigate the adverse effects of salinity stress and enhance the performance in pomegranates. This experiment was conducted in 2021 to investigate the effects of salinity stress (control, 4, and 8 dS/m) and inoculation with Pseudomonas fluorescens and Glomus mosseae, either individually or in combination (Pf+Gm), on Red Angel and Wonderful pomegranate cultivars. The results revealed a significant difference in the percentage of symbiosis and colonization among the biofertilizer treatments. Pf+Gm exhibited the highest percentages of symbiosis and colonization, followed by P. fluorescens. While salinity levels did not significantly affect symbiosis percentage, they had a detrimental effect on colonization percentage. Furthermore, biofertilizer treatments significantly increased leaf density, stem growth, total chlorophyll, and total anthocyanin, while reducing ion leakage and salinity damage index. In comparison to the non-inoculated control, the Pf+Gm treatment resulted in a 53.2 % decrease in ion leakage for the Red Angel cultivar and a 39.9 % decrease for the Wonderful cultivar. Salinity had a significant effect on proline production, with the Red Angel cultivar exhibiting the highest proline content (2.09 µmol/g) in response to salinity stress of 8 ds/m. However, biofertilizer treatments increased proline content in both cultivars. In Red Angel, the Pf+Gm treatment resulted in the highest proline production in the leaves (5.82 µmol/g), which was 123 % higher than that of the non-inoculated control. Additionally, the transpiration rate decreased with increasing salinity levels, and biofertilizer treatments had varying effects on photosynthetic gas exchange and electron transport rate. The interaction effect of biofertilizer treatments and salinity on CO2 absorption was highly significant, with Pf+Gm treatment exhibiting the highest absorption (8.51 and 8.61 µmol/m2/s in Red Angel and Wonderful, respectively). These findings suggest that applied biofertilizer treatments, especially Pf+Gm, can be an effective strategy for alleviating the negative effects of salinity stress on pomegranate cultivation.

Effect of GA3 and calcium on growth, biochemical, and fatty acid composition of linseed under chloride-dominated salinity.

The accumulation of salts in soil is an environmental threat affecting plant growth and crop yield. Linseed or flax is an ancient crop that has multifarious utilities in terms of industrial oil, textile fiber, and products. Salt susceptibility adversely affects linseed production, particularly to meet the growing demand for nutritional and nutraceutical products. In the present study, the ameliorative potential of gibberellic acid (GA3) and calcium (Ca2+) in mitigating the adverse effects of chloride-dominated salinity stress on the growth and physiological and biochemical processes in linseed was determined. Severe salinity treatment (10 dSm-1) resulted in stunted growth of tested linseed genotypes causing a significant reduction in biomass while proline content, phenol, H2O2, lipid peroxidation, and DPPH activity were increased in comparison to control. The exogenous application of 10-6M GA3 and/or 10mg CaCl2 kg-1 was found to mitigate the adverse effects of salinity stress. The mitigation was accomplished through the improvement of growth indicators, increased osmoprotectants such as proline and phenol content, stimulating DPPH activity, and reduction of H2O2 content and lipid peroxidation. The comparative evaluation of different saline treatments imposed individually and in combination with GA3 and Ca2+ revealed that combined GA3 and Ca2+ application exhibited synergistic effects and was most effective in mitigating the negative impacts of salt stress. The present study unravels the ameliorative role of GA3 and Ca2+ (individual or combined) in the physiologic-biochemical adaptive response of linseed plants grown under chloride-dominated salinity and thus aids in a better understanding of the underlying tolerance mechanisms of plants to withstand stress in saline environments.

Hydrogen peroxide priming promotes salinity tolerance in plants—A comprehensive review

AbstractSalinity stress is a growing concern for agriculture, as soil salinization is increasing worldwide and seriously affects global agricultural production and food security. How to minimize the adverse effects of salinity stress and meet the food needs of the growing human population becomes an urgent problem. Conventional techniques in agriculture and recently modern plant science have limitations; therefore, alternative technologies such as hydrogen peroxide (H2O2) priming have emerged as promising solutions. The findings highlight that H2O2 priming enhances antioxidant defenses, regulating the balance between reactive oxygen species production and scavenging. Furthermore, H2O2 priming promotes osmotic adjustment by stimulating the accumulation of osmoprotectants, maintaining cellular water status under salinity conditions. The review also discusses how H2O2 priming modulates gene expression and signaling processes, causing stress‐responsive genes and transcription factors activation. Moreover, H2O2 priming helps to preserve chloroplast integrity and photosynthetic efficiency, mitigating the detrimental impacts of salt stress on plant development and productivity. Overall, the collective knowledge gathered here, covering various aspects of the H2O2 priming phenomenon, may facilitate the design and conduct of future research on plant tolerance to salinity or other abiotic stresses. However, future research needs to focus on elucidating how priming can be applied on a large scale to diverse plants, understanding biochemical and molecular mechanisms of H2O2 priming for precise and reliable applications of this approach, and figuring out the potential benefits of in vitro priming (H2O2) technology in plant science.

Enhancement the Quality and Productivity of Canola (Brassica napus L.) Using Some Bio Stimulant Applications under Saline Soil Conditions

Salinity is one of the most serious and significant challenges facing the agricultural sector. It directly damages soil irrecoverably and negatively affects the quality and productivity of many crops. Priming is a process of seeds treatment with a rapid soaking with drying the seeds before setting, using for regulating the germination process by managing and regulating the temperature and seed moisture content. Priming involves advancing the seed to enable fast and uniform emergence. Once, field’s condition (temperature and moisture) is appropriate, germination occurs in a much shorter time. Several benefits to seed priming, and they include: faster speed of emergence, enables seed to germinate and emerge even under adverse agro-climatic conditions, improves uniformity to optimize harvesting efficiency, increases vigor for fast and strong plant development and increases yield potential. Hence, how to use priming is still a challenge that remains to be solved. This experiment was carried out in two winter seasons 2021/2022 and 2022/2023 at Tag El-Ezz Research Station ARC in Egypt, using canola (Brassica napus L.) var. Serw 4 with adding two potassium humate treatments (zero as control and 2 kg.fed-1) as main plots, two selenium applying methods (priming and foliar) as sub main plot and four rates of selenium application (zero as control, 1.5, 3.0 and 4.5 ppm) as sub sub-plots and their interactions on canola plant growth, yield and yield components. Some chemical composition and oil percentages in canola seeds were analyzed. After harvest, soil's available N, P and K were determined. Results could be summarized as follow: Humate applied at 2 kg. fed-1 increased chlorophyl (a+b) by 3.84%, yield by 8.65% and oil content by 1.76% comparing with the control. Humate application alleviates adverse effect of salinity stress and maximize oil yield comparing with without humate application. Priming is more effective than foliar application. Selenium application at 1.5 ppm is the superior rate followed by 3.0 ppm, control and 4.5 ppm at the least. The interactions between humate and Canola seed priming in 1.5 ppm selenium mitigate the harmful effect of soil salinity on Canola and increased yield, productivity and quality.

Biochar derived from olive oil pomace mitigates salt stress on seedling growth of forage pea.

Studies are being conducted to develop strategies to reduce the adverse effects of salinity stress. In the present study, it was aimed to determine the interactive effects of salinity stress with biochar on plant growth-the physiological and biochemical attributes of forage peas (Pisum sativum ssp. arvense L.). Salt applications were carried out with irrigation water at concentrations of 0, 25, 50, 75, and 100 mM NaCl. The experiment was conducted using a randomized complete block design with three applications [control: 0 (B0), 2.5% biochar (B1), and 5% biochar (B2)], five salt doses [0 (S0), 25 (S1), 50 (S2), 75 (S3), and 100 (S4) mM NaCl], and three replications, arranged in a 3 × 5 factorial arrangement. In the salt-stressed environment, the highest plant height (18.75 cm) and stem diameter (1.71 mm) in forage pea seedlings were obtained with the application of B1. The root fresh (0.59 g/plant) and dry weight (0.36 g/plant) were determined to be the highest in the B1 application, both in non-saline and saline environments. A decrease in plant chlorophyll content in forage pea plants was observed parallel to the increasing salt levels. Specifically, lower H2O2, MDA, and proline content were determined at all salt levels with biochar applications, while in the B0 application these values were recorded at the highest levels. Furthermore, in the study, it was observed that the CAT, POD, and SOD enzyme activities were at their lowest levels at all salt levels with the biochar application, while in the B0 application, these values were determined to be at the highest levels. There was a significant decrease in plant mineral content, excluding Cl and Na, parallel to the increasing salt levels. The findings of the study indicate that biochar amendment can enhance forage peas' growth by modulating the plant physiology and biochemistry under salt stress. Considering the plant growth parameters, no significant difference was detected between 2.5% and 5% biochar application. Therefore, application of 2.5 biochar may be recommended.

Endophytic fungi are able to induce tolerance to salt stress in date palm seedlings (Phoenix dactylifera L.).

Date palm, typically considered a salinity-resistant plant, grows in arid and semi-arid regions worldwide, and experiences decreased growth and yields under salt stress. This study investigates the efficacy of endophytic fungi (EF) in enhancing the salinity tolerance of date palm seedlings. In this experiment, EF were isolated from date tree roots and identified morphologically. Following molecular identification, superior strains were selected to inoculate date palm seedlings (Phoenix dactylifera L., cv. Mazafati). The seedlings were subjected to varying levels of salinity stress for 4months, utilizing a completely randomized factorial design with two factors: fungal strain type (six levels) and salinity stress (0, 100, 200, and 300mM sodium chloride). The diversity analysis of endophytic fungi in date palm trees revealed that the majority of isolates belonged to the Ascomycota family, with Fusarium and Alternaria being the most frequently isolated genera. In this research, the application of fungal endophytes resulted in increased dry weight of roots, shoots, root length, plant height, and leaf number. Additionally, EF symbiosis with date palm seedling roots led to a reduction in sodium concentration and an increase in potassium and phosphorus concentrations in aerial parts under salt-stress conditions. While salinity elevated lipid peroxidation, consequently increasing malondialdehyde (MDA) levels, EF mitigated damage from reactive oxygen species (ROS) by enhancing antioxidant enzyme activity, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), while promoting proline and total soluble sugar (TSS) accumulation. The colonization percentage generally increased with salinity stress intensity in most strains. According to the results, the application of EF can alleviate the adverse effects of salinity stress and enhance the growth of date palm seedlings under saline conditions.

Mitigation of the Adverse Effects of Salinity Stress on Walnut (Juglans regia L.) by Ascorbic Acid under In Vitro Conditions

Mitigation of the Adverse Effects of Salinity Stress on Walnut (Juglans regia L.) by Ascorbic Acid under In Vitro Conditions

Foliar treatment with melatonin modulates photosynthetic and antioxidant responses in Silybum marianum L. under salt stress

Salinity is a significant global environmental problem that alters the physiology and morphology of plants. Melatonin modulates several physiological activities in plants under various environmental stresses. However, the contribution of melatonin to stress tolerance in response to salinity remains yet unclear. Therefore, the present study was conducted to investigate the potential impact of melatonin on various physiological reactions and metabolic processes in milk thistle (Silybum marianum) exposed to salinity stress. Salinity causes a reduction in photosynthesis and an increase in free radical production, ultimately resulting in growth inhibition. To combat the adverse effects of salinity stress, milk thistle produced increased levels of antioxidant compounds compared with control group. However, this increase in antioxidant activity could not help the plant in tolerating salinity stress. Conversely, foliar treatment of 100 µM melatonin improved photosynthesis (Pn) 64 %, relative water contents RWC (30.8 %), photochemical efficiency 0.44, antioxidant activities, and seedling characteristics in salinity-exposed plants compared with those in the negative control. Moreover, treatment with 100 µM melatonin resulted in better salinity tolerance by enhancing physiological changes such as stomatal conductance, transpiration, CO2 concentration, photosynthesis, germination, and generation of reactive oxygen species and reducing the hydrogen peroxide concentration in milk thistle plants under salinity stress.

Enhancing Chickpea (Cicer arietinum L.) Tolerance to Salinity through Plant Growth Regulators

During the period of 2020-21, a research study was carried out at the Plant Protective Culture Unit within the semi-controlled environmental settings of the Bangladesh Agricultural Research Institute. The aim of the study was to mitigate the negative impacts of salinity stress on chickpea by applying various concentrations of salicylic acid (SA) and gibberellic acid (GA3). Plants were subjected to four different levels of salinity stress, including a control group, mild stress, moderate stress, and severe stress. This was achieved by irrigating them with four varying concentrations of saline water (5, 7.5, 10 and 12.5 dSm-1) starting from the 14th day after sowing (DAS) and continuing until maturity at 100 DAS. On the other hand, the control plants received regular irrigation with tap water. Two concentrations of salicylic acid (SA) specifically 200 ppm and 400 ppm, along with gibberellic acid (GA3) at 10 ppm and 20 ppm, were administered as a foliar spray once a week, commencing at 20 days after sowing (DAS) and continuing until the flowering stage. Data related to chlorophyll levels in the leaves and water-related traits, including relative water content (RWC) and water retention capacity (WRC) were collected seven days after the foliar spray of these plant growth regulators at the flowering stage. Additionally, measurements of total dry weight, yield, and various yield-contributing factors were taken at the point of maturity. The results indicated that chickpea suffered adverse consequences due to salinity stress which included a reduction in chlorophyll content, a decrease in relative water content, a decline in water retention capacity, a decrease in total dry weight and a lower overall yield. However, the foliar application of different doses of salicylic acid (SA) and gibberellic acid (GA3) under varying levels of salinity stress had beneficial effects in alleviating the impact of salinity stress. Interestingly, it was observed that lower concentrations of SA at 200 ppm and GA3 at 10 ppm were more effective in mitigating the adverse effects of salinity stress and improving salinity tolerance in chickpea, especially under mild salinity stress conditions (5 dSm-1) as evidenced by the positive influence on the parameters mentioned above.

Seed Priming with Salicylic Acid Alleviates Salt Stress Toxicity in Barley by Suppressing ROS Accumulation and Improving Antioxidant Defense Systems, Compared to Halo- and Gibberellin Priming.

Plants are highly sensitive to various environmental stresses, which can hinder their growth and reduce yields. In this study, we investigated the potential of seed priming with salicylic acid (SA), gibberellic acid (GA3), and sodium chloride (NaCl) to mitigate the adverse effects of salinity stress in Hordeum vulgare at the germination and early seedling stages. Exposing H. vulgare seeds to salt stress reduced the final germination percentage and seedling shoot and root growth. Interestingly, all seed treatments significantly improved salt-induced responses, with GA3 being more effective in terms of germination performance, plant growth, and photosynthesis. SA priming exhibited promising effects on antioxidant defense mechanisms, proline, sugar, and ascorbic acid production. Notably, SA priming also suppressed reactive oxygen species accumulation and prevented lipid peroxidation. These findings highlight the ability of SA to manage crosstalk within the seed, coordinating many regulatory processes to support plant adaptation to salinity stress.