Salt Stress Conditions Research Articles

Functional analysis of the carnosine synthase-like gene conserved in Monoraphidium braunii

Carnosine, a dipeptide composed of β-alanine and histidine, is predominantly found in animals such as mammals, birds, and fish, with no known presence in plants, microalgae, and other organisms. It can undergo methylation to produce anserine, β-alanyl-N-methyl-L-histidine. These imidazole peptides are known for their antioxidative properties and fatigue recovery effects. The synthesis of carnosine is catalyzed by carnosine synthase, encoded by the ATPGD1 or CARNS1 gene. Recently, homologous proteins to carnosine synthase have been reported from several microalgal genomes, although their biological functions remain unknown. In this study, we investigated the role of carnosine synthase-like protein in the green alga Monoraphidium braunii SAG 48.87. Initially, we examined the accumulation of carnosine and anserine in M. braunii cells cultivated under various conditions. Interestingly, salt stress induced the accumulation of anserine. The cells treated with 420 mM NaCl accumulated 38.3 μg g−1 dry weight (DW) of anserine. Expression of ATPGD1a, putatively annotated as a carnosine synthase gene, was induced under salt stress conditions, while expression of ATPGD1b was downregulated. The Escherichia coli cells expressing the recombinant ATPGD1a primarily accumulated anserine (269.9 μg g−1 DW) and a small amount of carnosine, although we could not confirm any carnosine or anserine synthesis by the purified recombinant protein. These findings suggest that the carnosine synthase homolog in microalgae may play a role in synthesizing imidazole dipeptides, and anserine could serve as a salt protective agent and help stabilize cellular functions, particularly under salt conditions. This is the first observation of the synthesis of the imidazole dipeptide from any organism except animals and anserine protecting from salt stress.

Chitosan nanoparticles encapsulating curcumin counteract salt-mediated ionic toxicity in wheat seedlings: an ecofriendly and sustainable approach.

Over-accumulating salts in soil are hazardous materials that interfere with the biochemical pathways in growing plants drastically affecting their physiological attributes, growth, and productivity. Soil salinization poses severe threats to highly-demanded and important crops directly challenging food security and sustainable productivity. Recently, there has been a great demand to exploit natural sources for the development of nontoxic nanoformulations of growth enhancers and stress emulators. The chitosan (CS) has growth-stimulating properties and widespread use as nanocarriers, while curcumin (CUR) has a well-established high ROS scavenging potential. Herein, we use CS and CUR for the preparation of CSNPs encapsulating CUR as an ecofriendly nanopriming agent. The hydroprimed, nanoprimed (0.02 and 0.04%), and unprimed (control) wheat seeds were germinated under salt stress (150 mM NaCl) and normal conditions. The seedlings established from the aforementioned seeds were employed for germination studies and biochemical analyses. Priming imprints mitigated the ionic toxicity by upregulating the machinery of antioxidants (CAT, POD, APX, and SOD), photosynthetic pigments (Chl a, Chl b, total Chl, and lycopene), tannins, flavonoids, and protein contents in wheat seedlings under salt stress. It controlled ROS production and avoided structural injuries, thus reducing MDA contents and regulating osmoregulation. The nanopriming-induced readjustments in biochemical attributes counteracted the ionic toxicity and positively influenced the growth parameters including final germination, vigor, and germination index. It also reduced the mean germination time, significantly validating the growth-stimulating and stress-emulating role of the prepared nanosystem. Hence, the nanopriming conferred tolerance against salt stress during germination and seedling development, ensuring sustainable growth.

Growth and protein response of rice plant with plant growth-promoting rhizobacteria inoculations under salt stress conditions.

Soil salinity has been one of the significant barriers to improving rice production and quality. According to reports, Bacillus spp. can be utilized to boost plant development in saline soil, although the molecular mechanisms behind the interaction of microbes towards salt stress are not fully known. Variations in rice plant protein expression in response to salt stress and plant growth-promoting rhizobacteria (PGPR) inoculations were investigated using a proteomic method and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Findings revealed that 54 salt-responsive proteins were identified by mass spectrometry analysis (LC-MS/MS) with the Bacillus spp. interaction, and the proteins were functionally classified as gene ontology. The initial study showed that all proteins were labeled by mass spectrometry analysis (LC-MS/MS) with Bacillus spp. interaction; the proteins were functionally classified into six groups. Approximately 18 identified proteins (up-regulated, 13; down-regulated, 5) were involved in the photosynthetic process. An increase in the expression of eight up-regulated and two down-regulated proteins in protein synthesis known as chaperones, such as the 60kDa chaperonin, the 70kDa heat shock protein BIP, and calreticulin, was involved in rice plant stress tolerance. Several proteins involved in protein metabolism and signaling pathways also experienced significant changes in their expression. The results revealed that phytohormones regulated the manifestation of various chaperones and protein abundance and that protein synthesis played a significant role in regulating salt stress. This study also described how chaperones regulate rice salt stress, their different subcellular localizations, and the activity of chaperones.

γ-aminobutyric acid (GABA) strengthened nutrient accumulation, defense metabolism, growth and yield traits against salt and endoplasmic reticulum stress conditions in wheat plants

γ-aminobutyric acid (GABA) strengthened nutrient accumulation, defense metabolism, growth and yield traits against salt and endoplasmic reticulum stress conditions in wheat plants

The Deletion of LeuRS Revealed Its Important Roles in Osmotic Stress Tolerance, Amino Acid and Sugar Metabolism, and the Reproduction Process of Aspergillus montevidensis.

Aspergillus montevidensis is an important domesticated fungus that has been applied to produce many traditional fermented foods under high osmotic conditions. However, the detailed mechanisms of tolerance to osmotic stress remain largely unknown. Here, we construct a target-deleted strain (ΔLeuRS) of A. montevidensis and found that the ΔLeuRS mutants grew slowly and suppressed the development of the cleistothecium compared to the wide-type strains (WT) under salt-stressed and non-stressed conditions. Furthermore, differentially expressed genes (p < 0.001) governed by LeuRS were involved in salt tolerance, ABC transporter, amino acid metabolism, sugar metabolism, and the reproduction process. The ΔLeuRS strains compared to WT strains under short- and long-term salinity stress especially altered accumulation levels of metabolites, such as amino acids and derivatives, carbohydrates, organic acids, and fatty acids. This study provides new insights into the underlying mechanisms of salinity tolerance and lays a foundation for flavor improvement of foods fermented with A. montevidensis.

Genome-wide identification and expression pattern analysis of the kiwifruit GRAS transcription factor family in response to salt stress

BackgroundGRAS is a family of plant-specific transcription factors (TFs) that play a vital role in plant growth and development and response to adversity stress. However, systematic studies of the GRAS TF family in kiwifruit have not been reported.ResultsIn this study, we used a bioinformatics approach to identify eighty-six AcGRAS TFs located on twenty-six chromosomes and phylogenetic analysis classified them into ten subfamilies. It was found that the gene structure is relatively conserved for these genes and that fragmental duplication is the prime force for the evolution of AcGRAS genes. However, the promoter region of the AcGRAS genes mainly contains cis-acting elements related to hormones and environmental stresses, similar to the results of GO and KEGG enrichment analysis, suggesting that hormone signaling pathways of the AcGRAS family play a vital role in regulating plant growth and development and adversity stress. Protein interaction network analysis showed that the AcGRAS51 protein is a relational protein linking DELLA, SCR, and SHR subfamily proteins. The results demonstrated that 81 genes were expressed in kiwifruit AcGRAS under salt stress, including 17 differentially expressed genes, 13 upregulated, and four downregulated. This indicates that the upregulated AcGRAS55, AcGRAS69, AcGRAS86 and other GRAS genes can reduce the salt damage caused by kiwifruit plants by positively regulating salt stress, thus improving the salt tolerance of the plants.ConclusionsThese results provide a theoretical basis for future exploration of the characteristics and functions of more AcGRAS genes. This study provides a basis for further research on kiwifruit breeding for resistance to salt stress. RT-qPCR analysis showed that the expression of 3 AcGRAS genes was elevated under salt stress, indicating that AcGRAS exhibited a specific expression pattern under salt stress conditions.

Spatio-temporal variation in synthesis of some nutraceutical components of thorowax foldwing (Dicliptera bupleuroides Nees)

The present research was carried out to determine the spatiotemporal variation in accumulation of different nutritional and medicinal components in Dicliptera bupleuroides from the Soone valley in the Salt Range of Punjab, Pakistan. Most of the biochemical attributes were higher in the spring season than those in the other seasons; this might have been due to high soil pH during spring. High amounts of minerals and high pH are necessary for the synthesis of alkaloids, phenols, flavonoids, and fibers. Proteins, N, dry matter, fats and nitrogen free extract (NFE) were higher in summer, which might have been due to considerable availability of macro-nutrients during this season due to high moisture content because of high rainfall during the season. Spatial variation showed that phenols and flavonoids were associated with the population from Khabeki site (despite enough minerals and moisture availability) which might have been due to physical injuries caused by grazing and cutting. Minerals, proteins and N were also associated with the Khabeki population probably due to large amounts of minerals and moisture retention in the soil of the site and prevalent optimum environmental conditions therein. Alkaloids, fats, moisture and some minerals were associated with Anga and Knotti Garden sites which might have been due to high pH and prolonged salt stressed conditions at both sites.

Salt stress and organic fertilization on the growth and biochemical metabolism of Hylocereus costaricensis (red pitaya) seedlings.

Red pitaya (Hylocereus costaricensis) is a promising species, with high cultivation potential due to the organoleptic and functional qualities of its fruits. However, irrigation water salinity can affect the crop yield. Therefore, materials rich in organic substances can minimize the damage caused by excess salts in soil and/or water. Thus, the objective of this study was to evaluate the influence of organic matter sources as attenuators of salt stress on the production and biochemical responses of red pitaya seedlings. A completely randomized design in 4 × 5 factorial scheme, with five sources of organic matter (humus, sheep manure, biofertilizer, organic compost and sand + soil) and four salinities (0.6, 2.6, 4.6 and 6.6 dS m-1) with four replicates and two plants per plot was used. The shoot length, root length, cladode diameter, number of cladodes, number of sprotus, root volume, shoot dry mass, root dry mass and total dry mass, root and shoot dry mass ratio, chlorophyll a, b and total, amino acids and soluble sugars were evaluated at 120 days after the treatments began to be applied. Red pitaya is moderately tolerant to salinity (ECw from 4.0 to 6.0 dS m-1). Organic compost and sheep manure attenuate the harmful effects of salinity on red pitaya seedlings. Under salt stress conditions, red pitaya plants increase their levels of proline, amino acids and total sugars.

Exogenous application of salicylic acid induces salinity tolerance in eggplant seedlings.

Under salt stress conditions, plant growth is reduced due to osmotic, nutritional and oxidative imbalance. However, salicylic acid acts in the mitigation of this abiotic stress by promoting an increase in growth, photosynthesis, nitrogen metabolism, synthesis of osmoregulators and antioxidant enzymes. In this context, the objective was to evaluate the effect of salicylic acid doses on the growth and physiological changes of eggplant seedlings under salt stress. The experiment was conducted in a greenhouse, where the treatments were distributed in randomized blocks using a central composite matrix Box with five levels of electrical conductivity of irrigation water (CEw) (0.50; 1.08; 2.50; 3.92 and 4.50 dS m-1), associated with five doses of salicylic acid (SA) (0.00; 0.22; 0.75; 1.28 and 1.50 mM), with four repetitions and each plot composed of three plants. At 40 days after sowing, plant height, stem diameter, number of leaves, leaf area, electrolyte leakage, relative water content, and total dry mass were determined. ECw and SA application influenced the growth and physiological changes of eggplant seedlings. Increasing the ECw reduced growth in the absence of SA. Membrane damage with the use of SA remained stable up to 3.9 dS m-1 of ECw. The relative water content independent of the CEw increased with 1.0 mM of SA. The use of SA at the concentration of 1.0 mM mitigated the deleterious effect of salinity on seedling growth up to 2.50 dS m-1 of ECw.

Effects of salt stress on bacterial community composition and diversity in rhizosphere soil of Bletilla striata

Salinization environment affects the normal growth and development of plants, as well as the microbial community in the rhizosphere. To explore the succession dynamics of bacterial communities in the rhizosphere soil of Bletilla striata under salt stress condition, we performed 16S rRNA high-throughput sequencing to determine the bacterial community composition and diversity of B. striata in the rhizosphere under different salt stress concentrations, measured the effects of salt stress on the growth and development of B. striata and soil physicochemical pro-perties, and analyzed the correlation between community composition of rhizosphere bacteria and the soil environmental factors. The results showed that compared with the control, salt stress reduced growth rate and health degree of B. striata, and significantly decreased the content of soil organic matter, nitrogen and phosphorus. Under the salt stress treatment, species diversity and evenness of the bacterial communities in the rhizosphere of B. striata showed a trend of first decreasing and then increasing. There were significant differences in the relative abundance and variation trends of the dominant bacterial taxa in the rhizosphere soil of B. striata at the phylum and class levels between the control and the salt stress treatments. Salt stress intensity and duration were important factors affecting bacterial community composition in the rhizosphere soil of B. striata. Soil organic matter, available nitrogen, and total phosphorus content were key environmental factors affecting the structure of rhizosphere bacterial community composition. Functional genes related to cytoskeleton, cell motility, substance metabolism and signal transduction mechanisms may be involved in the adaptation and stress response of bacterial communities to salt stress. This study would provide theoretical basis and reference for the cultivation management of B. striatain saline area.

Abiotic stress tolerance in pearl millet: Unraveling molecular mechanisms via transcriptomics.

Pearl millet (Pennisetum glaucum (L.)) is a vital cereal crop renowned for its ability to thrive in challenging environmental conditions; however, the molecular mechanisms governing its salt stress tolerance remain poorly understood. To address this gap, next-generation RNA sequencing was conducted to compare gene expression patterns in pearl millet seedlings exposed to salt stress with those grown under normal conditions. Our RNA sequencing analysis focused on shoots from 13-day-old pearl millet plants subjected to either salinity stress (150 mmol of NaCl for 3 days) or thermal stress (50°C for 60 s). Of 36,041 genes examined, 17,271 genes with fold changes ranging from 2.2 to 19.6 were successfully identified. Specifically, 2388 genes were differentially upregulated in response to heat stress, whereas 4327 genes were downregulated. Under salt stress conditions, 2013 genes were upregulated and 4221 genes were downregulated. Transcriptomic analysis revealed four common abiotic KEGG pathways that play crucial roles in the response of pearl millet to salt and heat stress: phenylpropanoid biosynthesis, photosynthesis-antenna proteins, photosynthesis, and plant hormone signal transduction. These metabolic pathways are necessary for pearl millet to withstand and adapt to abiotic stresses caused by salt and heat. Moreover, the pearl millet shoot heat stress group showed specific transcriptomics related to KEEG metabolic pathways such as cytochrome P450, cutin, suberine, and wax biosynthesis, zeatin biosynthesis, crocin biosynthesis, ginsenoside biosynthesis, saponin biosynthesis, and biosynthesis of various plant secondary metabolites. In contrast, pearl millet shoots exposed to salinity stress exhibited transcriptomic changes associated with KEEG metabolic pathways related to carbon fixation in photosynthetic organisms, mismatch repair, and nitrogen metabolism. Our findings underscore the remarkable cross-tolerance of pearl millet to simultaneous salt and heat stress, elucidated through the activation of shared abiotic KEGG pathways. This study emphasizes the pivotal role of transcriptomics analysis in unraveling the molecular responses of pearl millet under abiotic stress conditions.

Identification and expression analysis of SBP-Box-like (SPL) gene family disclose their contribution to abiotic stress and flower budding in pigeon pea (Cajanus cajan).

The SPL gene family (for Squamosa Promoter-binding like Proteins) represents specific transcription factors that have significant roles in abiotic stress tolerance, development and the growth processes of different plants, including initiation of the leaf, branching and development of shoot and fruits. The SPL gene family has been studied in different plant species; however, its role is not yet fully explored in pigeon pea (Cajanus cajan ). In the present study, 11 members of the CcSPL gene family were identified in C. cajan . The identified SPLs were classified into nine groups based on a phylogenetic analysis involving SPL protein sequences from C. cajan , Arabidopsis thaliana , Cicer arietinum , Glycine max , Phaseolus vulgaris , Vigna unguiculata and Arachis hypogaea . Further, the identification of gene structure, motif analysis, domain analysis and presence of cis -regulatory elements in the SPL family members were studied. Based on RNA-sequencing data, gene expression analysis was performed, revealing that CcSPL2.1, 3 and 13A were significantly upregulated for salt-tolerance and CcSPL14 and 15 were upregulated in a salt-susceptible cultivar. Real-time qPCR validation indicated that CcSPL3, 4, 6 and 13A were upregulated under salt stress conditions. Therefore, molecular docking was performed against the proteins of two highly expressed genes (CcSPL3 and CcSPL14 ) with three ligands: abscisic acid, gibberellic acid and indole-3-acetic acid. Afterward, their binding affinity was obtained and three-dimensional structures were predicted. In the future, our study may open avenues for harnessing CcSPL genes in pigeon pea for enhanced abiotic stress resistance and developmental traits.

RNA-seq analysis reveals transcriptome reprogramming and alternative splicing during early response to salt stress in tomato root.

Salt stress is one of the dominant abiotic stress conditions that cause severe damage to plant growth and, in turn, limiting crop productivity. It is therefore crucial to understand the molecular mechanism underlying plant root responses to high salinity as such knowledge will aid in efforts to develop salt-tolerant crops. Alternative splicing (AS) of precursor RNA is one of the important RNA processing steps that regulate gene expression and proteome diversity, and, consequently, many physiological and biochemical processes in plants, including responses to abiotic stresses like salt stress. In the current study, we utilized high-throughput RNA-sequencing to analyze the changes in the transcriptome and characterize AS landscape during the early response of tomato root to salt stress. Under salt stress conditions, 10,588 genes were found to be differentially expressed, including those involved in hormone signaling transduction, amino acid metabolism, and cell cycle regulation. More than 700 transcription factors (TFs), including members of the MYB, bHLH, and WRKY families, potentially regulated tomato root response to salt stress. AS events were found to be greatly enhanced under salt stress, where exon skipping was the most prevalent event. There were 3709 genes identified as differentially alternatively spliced (DAS), the most prominent of which were serine/threonine protein kinase, pentatricopeptide repeat (PPR)-containing protein, E3 ubiquitin-protein ligase. More than 100 DEGs were implicated in splicing and spliceosome assembly, which may regulate salt-responsive AS events in tomato roots. This study uncovers the stimulation of AS during tomato root response to salt stress and provides a valuable resource of salt-responsive genes for future studies to improve tomato salt tolerance.

Impact of different zinc concentrations on growth, yield, fruit quality, and nutrient acquisition traits of tomato (Lycopersicon esculentum L.) grown under salinity stress

Salinity stress affects plant growth, development, nutrient uptake, and yield. Applications of micronutrients, specifically zinc (Zn), can mitigate the harmful consequences of salt stress. During the winter season of 2022, an experiment was conducted in the net house of BINA substation Satkhira, Bangladesh, to examine the impact of different Zn concentrations (5 and 10 kg ha-1) on tomato (Lycopersicon esculentum L.) growth, yield, fruit quality, and nutrient acquisition abilities under different salt stress (SS) conditions (SS0.5%, SS1.0%, and SS1.5% NaCl). The result of the study showed that different stress conditions lowered the plant height, the number of branches per plant, flower clusters, and fruits per plant, plant yield, vitamin C, protein and lycopene contents, and the acquisition of different nutrients, i.e., nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn) and iron (Fe). The application of 10 kg Zn ha-1 (Zn10) increased all previously mentioned parameters in both saline and usual conditions. On the other hand, a decrease in the amount of Na in fruit was observed when Zn application was increased from 5 to 10 kg ha-1. Plant Na/K ratios were consequently lowest at the highest Zn concentration. Therefore, the findings indicate that Zn application improves tomato growth, yield, fruit quality, and nutrient acquisition traits by mitigating the negative impacts of saline environments.

Multivalent nanobody engineering for enhanced physisorption and functional display on gold nanoparticles.

The ease of expression and engineering of single domain antibodies, known as nanobodies, make them attractive alternatives to conventional antibodies in point-of-care diagnostics such as lateral flow assays. In lateral flow assays, gold nanoparticle bioconjugates serve as labels which display affinity molecules on the gold surface. While examples of nanobody gold nanoparticle bioconjugates exist, few utilise the simple one-step approach of physisorption owing to undesirable nanoparticle aggregation and loss of functionality. Here we show that engineering nanobodies into multivalent structures can significantly enhance their functionality when physisorbed onto gold nanoparticles. This approach enables resulting bioconjugates to withstand multiple processing steps required for long-term nanoparticle storage within lateral flow assays. Specifically, we show that the trivalent version of VHHV nanobody (VHH3) against the S1 protein of SARS-CoV-2 can be immobilised onto gold nanoparticles through passive adsorption. Unlike its monovalent and bivalent nanobody counterparts, using VHHV3 preserves nanoparticle stability under salt stress, blocking, washing, and freeze-drying conditions while maintaining picomolar sensitivity to the S1 protein. We anticipate that this facile strategy is a significant advancement towards the integration of nanobodies in lateral flow assay development.

Effect of antioxidant enzymes and electrolytes of Aloe vera juice on the toxicity induced by ethionamide and para-aminosalicylic acid on Sprague-Dawley rats

Background: This aim is so widely used and believed to have healing properties that it is called “true aloe.” Aloe vera has been used for centuries to treat laxity and as a cleansing cleanser. Some of the most common health benefits of are as follows: Promotes wound healing, anti-fungal activity, hypoglycemia or antidiabetes effects, anti-inflammatory properties, anticancer properties, immobilomodulatory properties, and gastroprotective properties. Aims and Objectives: The objective of this study was to determine the antioxidant activity of A. vera juice against antituberculosis drugs ethionamide (ETH) and para-aminosalicylic acid (PAS) by quantifying antioxidant enzymes such as glutathione (GSH) and malondialdehyde (MDA) and catalase (CAT) and electrolytes in rats. Materials and Methods: Fresh leaves of A. vera were collected from botanical garden and the sample was identified. The sample was brought to the laboratory of the Department of Zoology at Patkar-Verde College, Goregaon, Mumbai. 50 g of leaves were ground with 50 mL of distilled water in a sterilized pestle and mortar and the yield so determined by comparing the weight of the extract with the weight of pulp. In the experiment, 48 Sprague-Dawley rats of either sex (average weight 150–250 g) were used. Each group was given the drugs ETH, PAS drug, and A. vera juice on a daily basis for 28 days. The serum of the rat was withdrawn and analyzed for antioxidant enzymes and electrolyte levels. Results: We observed a decrease in the level of GSH in rats treated with anti-tuberculosis (TB) drugs ETH and PAS. However, when A. vera juice was coadministered with PAS, either independently or in combination, it resulted in improved levels of GSH. In addition, the rats treated with A. vera juice showed a decrease in the level of MDA. Furthermore, coadministration of A. vera juice in combination with ETH + PAS + A. vera juice led to increased levels of CAT in rats. The concentration of Na+ in rats treated with A. vera juice in combination with ETH and PAS showed a decrease, which could potentially aid in normal metabolism. On the other hand, the elevation of K+ in the rats treated with A. vera juice indicates their adaptation to salinity, as K+ levels act somatically to prevent influx into roots and shoots. This elevation in K+ can be utilized to lower salt levels in rats experiencing stress. Moreover, the rats treated solely with A. vera juice exhibited the lowest level of Ca+, confirming their low salt stress condition. Finally, it was observed that the rats treated with A. vera juice experienced depletion in A. vera concentration. Conclusion: Based on the aforementioned findings, it can be inferred that A. vera is rich in phenolic and flavonoids, which exhibit antioxidant properties. This unequivocally demonstrates that possesses the ability to scavenge free radicals and plays a beneficial role in combating pathological conditions induced by reactive oxygen species. Furthermore, it has been established that reduces electrolyte levels and diminishes salt accumulation in comparison to groups administered with anti-TB medications ETH and PAS.

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.

The effect of zinc application on growth and alleviating shoot concentration of cadmium in durum wheat plant growth under conditions of salt and cadmium stress

A study was conducted in a greenhouse to investigate the effect of the combination of cadmium (Cd) and salinity (NaCl) stress in zinc (Zn) deficiency on growth, Cd accumulation in durum wheat (Triticum turgidum L. durum, cv. Balcali-2000), and micro (Zn, Fe, Cu, Mn) minerals differing in salt tolerance. The negative effects of Cd and NaCl stress on plant growth and Cd accumulation detected to alleviate Cd uptake on wheat growth increasing zinc application. The results revealed that Cd, NaCl and their combined stresses reduced shoots dry matter and Cd concentration in shoots increased compared to control pots. In increasing Cd and NaCl treatments, increasing Zn application significantly decreased the Cd concentration in shoot. In particularly, the decrease in Cd concentration was more noticeable with the improvement of Zn nutrition of plants at low doses of NaCl and Cd. The effect of increasing zinc treatments on reducing Cd accumulation decreased to slightly at high doses of Cd and NaCl. According to the results it can be suggested that Zn application to soils with low Cd content and medium salinity can be reduce Cd uptake by durum wheat.

Genome-wide identification and expression analysis of the chlorophyll a/b binding protein gene family in oilseed (Brassica napus L.) under salt stress conditions

To elucidate the functions and molecular mechanisms of BnLhc gene family members in Brassica napus under different exogenous hormones and abiotic stress, we identified 57 BnLhc gene family members from the entire genome of B. napus variety ZS11 using Arabidopsis Lhc protein as a seed sequence combined with phyll A-B binding protein PF00504. We performed comprehensive analyses including physicochemical property analysis, structural analysis, phylogenetic relationship analysis, homology relationship analysis, protein interaction network analysis, microRNA-target gene interaction analysis and GO enrichment analysis. Additionally, based on transcriptome data, we investigated response patterns of BnLhc genes to various exogenous stress conditions. Comparative evaluation between non-salt (NS:0) and salt-treated (TS: 1) rapeseed plants revealed significant inhibition in leaf chlorophyll content, biomass (W), leaf area (LA), root surface area (RA), as well as chloroplasts and roots under salt treatment. Furthermore, qPCR was employed to assess the relative expression levels of BnLhc genes associated with salt tolerance. Our findings indicate that while BnLhcs were upregulated in leaves upon exposure to salt signals suggesting their potential involvement in enhancing rape's resistance to salt stress through ion redistribution processes; they were downregulated in roots. This study provides valuable insights into the functionality and molecular genetic mechanisms underlying the role BnLhc gene family

Exogenous γ-Aminobutyric Acid Can Improve Seed Germination and Seedling Growth of Two Cotton Cultivars under Salt Stress.

Excessive salt content in soil has adverse effects on cotton production, especially during the germination and seedling stages. γ-aminobutyric acid (GABA) is an important active substance that is expected to improve the resistance of plants to abiotic stresses. This study focused on two cotton cultivars (Gossypium hirsutum L.: Tahe 2 and Xinluzhong 62) and investigated the impact of exogenous GABA (0, 1, 2, 3, and 4 mM) on seed germination, seedling growth, and related morphological, physiological, and biochemical indicators under salt stress (150 mM NaCl). The results showed that salt stress significantly reduced the germination rate and germination index of cotton seeds (decreased by 20.34% and 32.14% for Tahe 2 and Xinluzhong 62, respectively), leading to decreased seedling height and biomass and causing leaf yellowing. Salt stress induced osmotic stress in seedlings, resulting in ion imbalance (marked reduction in K+/Na+ ratio) and oxidative damage. Under salt stress conditions, exogenous GABA increased the germination rate (increased by 10.64~23.40% and 2.63~31.58% for Tahe 2 and Xinluzhong 62, respectively) and germination index of cotton seeds, as well as plant height and biomass. GABA treatment improved leaf yellowing. Exogenous GABA treatment increased the content of proline and soluble sugars, with varying effects on betaine. Exogenous GABA treatment reduced the Na+ content in seedlings, increased the K+ content, and increased the K+/Na+ ratio (increased by 20.44~28.08% and 29.54~76.33% for Tahe 2 and Xinluzhong 62, respectively). Exogenous GABA treatment enhanced the activities of superoxide dismutase and peroxidase, and reduced the accumulation of hydrogen peroxide and malondialdehyde, but had a negative impact on catalase activity. In conclusion, exogenous GABA effectively improved cotton seed germination. By regulating osmoprotectant levels, maintaining ion homeostasis, and alleviating oxidative stress, GABA mitigated the adverse effects of salt stress on cotton seedling growth.