Investigating Sulforaphane's anti-virulence and anti-quorum sensing properties against Pseudomonas aeruginosa.

Background: P. aeruginosa, a significant bacterium, can cause severe illness and resistance to antibiotics. Quorum sensing (QS) systems regulate virulence factors production. Targeting QS could reduce bacteria pathogenicity and prevent antibiotic resistance. Cruciferous vegetables contain sulforaphane, known for its anti-inflammatory, antioxidant, anticancer, and antimicrobial properties. Aim: We aimed to examine the inhibitory influences of sulforaphane, at a sub-inhibitory concentration (» minimum inhibitory concentration, MIC), on virulence and QS in P. aeruginosa. Materials and methods: The sulforaphane's anti-virulence actions at sub-inhibitory concentrations were explored in vitro and in vivo. A sub-MIC concentration of sulforaphane was combined with anti-pseudomonal drugs, and the results of this combination were assessed. The virtual affinity of sulforaphane for the receptors of QS was studied, and its effect on the expression of QS genes was quantified. Results: Sulforaphane significantly decreased the biofilm formation, motility, ability to withstand oxidative stress, and the synthesis of virulence extracellular enzymes such as proteases, hemolysins, and elastase, as well as other virulence factors like pyocyanin. In addition, sulforaphane lessened the severity of P. aeruginosa infection in mice. Sulforaphane reduced the antipseudomonal antibiotics' MICs when used together, resulting in synergistic effects. The observed anti-virulence impacts were attributed to the ability of sulforaphane to inhibit QS via suppressing the QS genes' expression. Conclusion: Sulforaphane shows promise as a potent anti-virulence and anti-QS agent that can be used alongside conventional antimicrobials to manage severe infections effectively. Furthermore, this study paves the way for further investigation of sulforaphane and similar structures as pharmacophores for anti-QS candidates.

Enhancing salt stress tolerance in wheat (Triticum aestivum) seedlings: insights from trehalose and mannitol.

Salinity stress, an ever-present challenge in agriculture and environmental sciences, poses a formidable hurdle for plant growth and productivity in saline-prone regions worldwide. Therefore, this study aimed to explore the effectiveness of trehalose and mannitol induce salt resistance in wheat seedlings. Wheat grains of the commercial variety Sakha 94 were divided into three groups : a group that was pre-soaked in 10 mM trehalose, another group was soaked in 10 mM mannitol, and the last was soaked in distilled water for 1 hour, then the pre soaked grains cultivated in sandy soil, each treatment was divided into two groups, one of which was irrigated with 150 mM NaCl and the other was irrigated with tap water. The results showed that phenols content in wheat seedlings increased and flavonoids reduced due to salt stress. Trehalose and mannitol cause slight increase in total phenols content while total flavonoids were elevated highy in salt-stressed seedlings. Furthermore, Trehalose or mannitol reduced salt-induced lipid peroxidation. Salt stress increases antioxidant enzyme activities of guaiacol peroxidase (G-POX), ascorbate peroxidase (APX), and catalase (CAT) in wheat seedlings, while polyphenol oxidase (PPO) unchanged. Trehalose and mannitol treatments caused an increase in APX, and CAT activities, whereas G-POX not altered but PPO activity were decreased under salt stress conditions. Molecular docking confirmed the interaction of Trehalose or mannitol with peroxidase and ascorbic peroxidase enzymes. Phenyl alanine ammonia layase (PAL) activity was increased in salt-stressed seedlings. We can conclude that pre-soaking of wheat grains in 10 mM trehalose or mannitol improves salinity stress tolerance by enhancing antioxidant defense enzyme and/or phenol biosynthesis, with docking identifying interactions with G-POX, CAT, APX, and PPO.

Eco-friendly approach to decrease the harmful effects of untreated wastewater on growth, yield, biochemical constituents, and heavy metal contents of carrot (Daucus carota L.).

Here, the impact of irrigation using untreated wastewater (WW) on carrots (Daucus carota L.) was examined. We hypothesized that the addition of ethylenediaminetetraacetic acid (EDTA), dry algal powder (Spirulina platensis or Chlorella vulgaris), and Salix alba leaves powder would function as chelators for harmful contaminants in wastewater. The findings showed that irrigation of carrot plants with the sampled untreated wastewater led to significant decreases in the shoot lengths, fresh, dry weights of shoots and roots at stage I, the diameter of roots, pigment content, carotenoids, total soluble carbohydrate content, and soluble protein content. Furthermore, a significantly increased level of proline, total phenols, and the activities of polyphenol oxidase (PPO), peroxidase (POX), superoxide dismutase (SOD), and catalase (CAT) was identified in stage I samples. In contrast to the stage I, the length of the roots, the number of leaves on each plant, wet and dry weights of the stage II roots were all greatly enhanced. In spite of the increased yield due to the wastewater irrigation, carrot roots irrigated with wastewater had significantly more cadmium (Cd), nickel (Ni), cobalt (Co), and lead (Pb) than is considered safe. Our data clearly show that the application of Spirulina platensis, Chlorella vulgaris, EDTA, and leaves powder of salix was able to alleviate the toxicity of wastewater on carrot plants. For example, we recorded a significant decrease in the accumulation of carrot's Cd, Ni, Co, and Pb contents. We conclude that the treatments with Spirulina platensis and Chlorella vulgaris can be utilized as eco-friendly tools to lessen the damaging effects of wastewater irrigation on carrot plants.

Evaluation of flaxseed lignan-enriched extract targeting autophagy, apoptosis, and hedgehog pathways against experimentally induced obesity.

Objective: This research investigated secoisolariciresinol diglucoside (SDG) flax extract effects on apoptosis, hedgehog (Hh), autophagy, and the anti-oxidation process in experimentally induced obesity. Materials and Methods: Forty rats were separated into two sets regarding either receiving a normal balanced diet or a high-fat diet (HFD) and then distributed into four groups: GI: The control group had a regular diet for 12 weeks. GII: animals received a high-fat meal and saline by gastric gavage. GIII: HFD obese rats treated with SDG extract orally (10 mg/kg/b.w.) and 1.18 mg SDG/kg in the diet for 4 weeks GIV: Normal balanced diet rats received SDG extract orally (10 mg/kg/b.w.) and 1.18 mg SDG/kg of chow for 12 weeks in addition to their regular balanced diet. Results: The administration of SDG extract exhibited a significant drop in body weight, glucose, lipid profile, and leptin compared to the obese group. It also improved the antioxidant levels (lowering the levels of malondialdehyde while increasing the total antioxidant capacity) and anti-inflammatory status (decreasing interleukin-6 and tumor necrosis factor-alpha). SDG extract downregulates the expression of HH genes (protein patched homolog 1, Hh-interacting protein, glioma-associated oncogene homolog 1, and smoothened receptor) in conjunction with the modulation of autophagy genes and apoptotic proteins. Conclusion: SDG extract showed improved anti-inflammatory and antioxidant status and downregulated the expression of HH genes while modulating autophagy genes and apoptotic proteins among obese rats, suggesting that it may be used to avert and manage obesity and its correlated complications by modulating oxidation, inflammation, autophagy, and apoptosis. Advanced future research on the SDG autophagy pathway to address obesity and its complications is mandatory.

Tea (Camellia sinensis (L.) Kuntze) as an emerging source of protein and bioactive peptides: A narrative review.

Tea residues represent one of the major agricultural wastes that are generated after the processing of tea. They account for 21-28% of crude protein and are often discarded without the extraction of valuable proteins. Due to various bioactivity and functional properties, tea proteins are an excellent alternative to other plant-based proteins for usage as food supplements at a higher dosage. Moreover, their good gelation capacity is ideal for the manufacturing of dairy products, jellies, condensation protein, gelatin gel, bread, etc. The current study is the first to comprehend various tea protein extraction methods and their amino acid profile. The preparation of tea protein bioactive peptides and hydrolysates are summarized. Several functional properties (solubility, foaming capacity, emulsification, water/oil absorption capacity) and bioactivities (antioxidant, antihypertensive, antidiabetic) of tea proteins are emphasized.

Biogenic silver nanoparticles eradicate of Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus (MRSA) isolated from the sputum of COVID-19 patients.

In recent investigations, secondary bacterial infections were found to be strongly related to mortality in COVID-19 patients. In addition, Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus (MRSA) bacteria played an important role in the series of bacterial infections that accompany infection in COVID-19. The objective of the present study was to investigate the ability of biosynthesized silver nanoparticles from strawberries (Fragaria ananassa L.) leaf extract without a chemical catalyst to inhibit Gram-negative P. aeruginosa and Gram-positive Staph aureus isolated from COVID-19 patient's sputum. A wide range of measurements was performed on the synthesized AgNPs, including UV-vis, SEM, TEM, EDX, DLS, ζ -potential, XRD, and FTIR. UV-Visible spectral showed the absorbance at the wavelength 398 nm with an increase in the color intensity of the mixture after 8 h passed at the time of preparation confirming the high stability of the FA-AgNPs in the dark at room temperature. SEM and TEM measurements confirmed AgNPs with size ranges of ∼40-∼50 nm, whereas the DLS study confirmed their average hydrodynamic size as ∼53 nm. Furthermore, Ag NPs. EDX analysis showed the presence of the following elements: oxygen (40.46%), and silver (59.54%). Biosynthesized FA-AgNPs (ζ = -17.5 ± 3.1 mV) showed concentration-dependent antimicrobial activity for 48 h in both pathogenic strains. MTT tests showed concentration-dependent and line-specific effects of FA-AgNPs on cancer MCF-7 and normal liver WRL-68 cell cultures. According to the results, synthetic FA-AgNPs obtained through an environmentally friendly biological process are inexpensive and may inhibit the growth of bacteria isolated from COVID-19 patients.

Inductive role of the brown alga Sargassum polycystum on growth and biosynthesis of imperative metabolites and antioxidants of two crop plants.

The potential of macroalgae as biostimulants in agriculture was proved worthy. Vicia faba and Helianthus annuus are socioeconomic crops owing to their increasing demand worldwide. In this work, we investigated the energetic role of seed presoaking and irrigation by the brown seaweed, Sargassum polycystum aqueous extract (SAE) on certain germination and growth traits, photosynthetic pigments, carbohydrates, phenolics, flavonoids, and the total antioxidant activity. Compared to the control plants, our consequences revealed that seeds that received the SAE improved all the germination and growth criteria for both crop plants. Furthermore, the SAE significantly increased the carotenoids, total photosynthetic pigments, and total carbohydrates by (14%, 7%, and 41%) for V. faba and (17%, 17%, and 38%) for H. annuus, respectively. Phenolics and flavonoids were significantly induced in Vicia but slightly promoted in Helianthu plants, whereas the total antioxidant activity in both crops non significantly elevated. Even though The NPK contents were significantly stimulated by the SAE in Vicia plants, the effect was different in Helianthus, where only nitrogen content was significantly enhanced, whereas phosphorus and potassium showed little enhancement. Thus, the SAE treatment is one of the superlative sustainable strategies for food, feed, and as excellent plant conditioner.

Polyphenols-Rich Extract of Calotropis procera Alone and in Combination with Trichoderma Culture Filtrate for Biocontrol of Cantaloupe Wilt and Root Rot Fungi.

Fungal diseases have always been a major problem for cantaloupe crops; however, synthetic fungicides are hazardous to humans and the environment. Consequently, a feasible alternative to fungicides without side effects could be by using bio agents and naturally occurring plants with antibacterial potential. This study has achieved a novel procedure for managing wilt and root rot diseases by potentially using Trichoderma sp. culture filtrates in consortium with plant extract of Calotropis procera, Rhizoctonia solani, Fusarium oxysporum, and Pythium ultimum, which were isolated from infected cantaloupe roots with identified root rot symptoms. The antagonistic activity of four Trichoderma isolates and analysis of antibiotics and filtrate enzymes of the most active Trichoderma isolate were determined as well as phytochemical analysis of C. procera plant extract using HPLC-UV. The obtained results showed that all Trichoderma isolates considerably lowered the radial growth of P. ultimum, R. solani, and F. oxysporum in varying degrees. The scanning electron micrographs illustrate the mycoparasitic nature of Trichoderma sp. on F. oxysporum. The phytochemical analysis of C. procera indicated that phenolic contents were the major compounds found in extracts, such as vanillin (46.79%), chlorogenic acid (30.24%), gallic acid (8.06%), and daidzein (3.45%) but including only a low amount of the flavonoid compounds rutin, naringenin, and hesperetin. The Pot experiment's findings showed that cantaloupe was best protected against wilting and root rot diseases when it was treated with both Trichoderma sp. culture filtrates (10%) and C. procera extract of (15 mg/mL), both alone and in combination. This study demonstrates that the application of bio agent Trichoderma spp. filtrate with C. procera phenol extract appears useful for controlling wilting and root rot disease in cantaloupe. This innovative approach could be used as an alternative to chemical fungicide for the control of wilting and rot root diseases.

Valorizing the usage of olive leaves, bioactive compounds, biological activities, and food applications: A comprehensive review.

Olive oil production is a significant source of economic profit for Mediterranean nations, accounting for around 98 percent of global output. Olive oil usage has increased dramatically in recent years, owing to its organoleptic characteristics and rising knowledge of its health advantages. The culture of olive trees and the manufacture of industrial and table olive oil produces enormous volumes of solid waste and dark liquid effluents, involving olive leaves, pomace, and olive oil mill wastewaters. These by-products cause an economic issue for manufacturers and pose major environmental concerns. As a result, partial reuse, like other agronomical production wastes, is a goal to be achieved. Because these by-products are high in bioactive chemicals, which, if isolated, might denote components with significant added value for the food, cosmetic, and nutraceutical sectors, indeed, they include significant amounts of beneficial organic acids, carbohydrates, proteins, fibers, and phenolic materials, which are distributed differently between the various wastes depending on the olive oil production method and table olive agronomical techniques. However, the extraction and recovery of bioactive materials from chosen by-products is a significant problem of their reasonable value, and rigorous detection and quantification are required. The primary aims of this review in this context are to outline the vital bioactive chemicals in olive by-products, evaluate the main developments in extraction, purification, and identification, and study their uses in food packaging systems and safety problems.

Protective Effect of γ-Aminobutyric Acid Against Chilling Stress During Reproductive Stage in Tomato Plants Through Modulation of Sugar Metabolism, Chloroplast Integrity, and Antioxidative Defense Systems.

Despite the role of γ-aminobutyric acid (GABA) in plant tolerance to chilling stress having been widely discussed in the seedling stage, very little information is clear regarding its implication in chilling tolerance during the reproductive stage of the plant. Here, we investigated the influence of GABA (1 and 2mM) as a foliar application on tomato plants (Solanum lycopersicum L. cv. Super Marmande) subjected to chilling stress (5°C for 6h/day) for 5 successive days during the flowering stage. The results indicated that applied GABA differentially influenced leaf pigment composition by decreasing the chlorophyll a/b ratio and increasing the anthocyanin relative to total chlorophyll. However, carotenoids were not affected in both GABA-treated and non-treated stressed plants. Root tissues significantly exhibited an increase in thermo-tolerance in GABA-treated plants. Furthermore, applied GABA substantially alleviated the chilling-induced oxidative damage by protecting cell membrane integrity and reducing malondialdehyde (MDA) and H2O2. This positive effect of GABA was associated with enhancing the activity of phenylalanine ammonia-lyase (PAL), catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX). Conversely, a downregulation of peroxidase (POX) and polyphenol oxidase (PPO) was observed under chilling stress which indicates its relevance in phenol metabolism. Interesting correlations were obtained between GABA-induced upregulation of sugar metabolism coinciding with altering secondary metabolism, activities of antioxidant enzymes, and maintaining the integrity of plastids' ultrastructure Eventually, applied GABA especially at 2mM improved the fruit yield and could be recommended to mitigate the damage of chilling stress in tomato plants.

Roles of Exogenous α-Lipoic Acid and Cysteine in Mitigation of Drought Stress and Restoration of Grain Quality in Wheat.

Cysteine (Cys) and α-lipoic acid (ALA) are naturally occurring antioxidants (sulfur-containing compounds) that can protect plants against a wide spectrum of environmental stresses. However, up to now, there are no conclusive data on their integrative roles in mitigation of drought stress in wheat plants. Here, we studied the influence of ALA at 0.02 mM (grain dipping pre-cultivation treatment) and Cys (25 and 50 ppm as a foliar application) under well watered and deficit irrigation (100% and 70% of recommended dose). The results showed that deficit irrigation markedly caused obvious cellular oxidative damage as indicated by elevating the malondialdehyde (MDA) and hydrogen peroxide content (H2O2). Moreover, water stressed plants exhibited multiple changes in physiological metabolism, which affected the quantitative and qualitative variables of grain yield. The enzymatic antioxidants, including superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and peroxidase (POX) were improved by Cys application. SOD and APX had the same response when treated with ALA, but CAT and POX did not. Moreover, both studied molecules stimulated chlorophyll (Chl) and osmolytes' biosynthesis. In contrast, the Chl a/b ratio was decreased, while flavonoids were not affected by either of the examined molecules. Interestingly, all above-mentioned changes were associated with an improvement in the scavenging capacity of reactive oxygen species (ROS), leaf relative water content (RWC), grain number, total grain yield, weight of 1000 kernels, gluten index, falling number, and alveographic parameters (P, W, and P/L values). Furthermore, heatmap plot analysis revealed several significant correlations between different studied parameters, which may explore the importance of applied Cys and ALA as effective compounds in wheat cultivation under water deficit conditions.

Application of soil biofertilizers to a clayey soil contaminated with Sclerotium rolfsii can promote production, protection and nutritive status of Phaseolus vulgaris.

Sclerotium rolfsii is a soil-borne fungus that causes big losses in productivity of various plant species including Phaseolus vulgaris L. The objectives of this study were to (1) evaluate the impacts of Sclerotium rolfsii on growth and production of common bean plants, (2) determine the effects of Sclerotium rolfsii on nutritive contents of beans, and (3) test the efficacy of bio-inoculants on suppressing plant infection with Sclerotium rolfsii. To fulfill these objectives, we used a coupled pot and field experimental approaches during two growing seasons. Common beans were inoculated with either arbuscular mycorrhizal fungi (Claroideoglomus etunicatum), Saccharomyces cerevisiae, or Trichoderma viride solely or in different combinations. Non-inoculated plants and fungicide treated ones were considered as reference treatments. Throughout these experiments, minimal amounts of rock phosphate were added during soil preparation for bio-inoculated treatments, while the non-inoculated reference treatments received a full dose of P as calcium superphosphate. Results revealed that all tested bioinoculants significantly raised the activities of plant defense enzymes i.e. chitinase, peroxidase and polyphenoloxidase as compared to non-inoculated control. Likewise, pre-, post- and plant survival percentages significantly increased due to these bio-inoculations. Increased survival percentages were attributed to the concurrent increases in uptake of N, P and Zn nutrients by plants treated with bioinoculants. In this concern, plant nutrients uptake was higher in combined than single bio-inoculant treatments. Moreover, the uptake values of plant nutrients owing to the combined bio-inoculants were higher than the corresponding ones achieved due to fungicide treatment. In conclusion, application of the tested bio-inoculants, especially the combined ones can be considered an eco-friendly approach that not only enhances plants resistance against infection with Sclerotium rolfsii but also improves plant nutritive status.

Bactericidal and In-Vitro Cytotoxic Efficacy of Silver Nanoparticles (Ag-NPs) Fabricated by Endophytic Actinomycetes and Their Use as Coating for the Textile Fabrics.

An endophytic strain of Streptomyces antimycoticus L-1 was isolated from healthy medicinal plant leaves of Mentha longifolia L. and used for the green synthesis of silver nanoparticles (Ag-NPs), through the use of secreted enzymes and proteins. UV-vis spectroscopy, Fourier-transform infrared (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) analyses of the Ag-NPs were carried out. The XRD, TEM, and FT-IR analysis results demonstrated the successful biosynthesis of crystalline, spherical Ag-NPs with a particle size of 13-40 nm. Further, the stability of the Ag-NPs was assessed by detecting the surface Plasmon resonance (SPR) at 415 nm for one month or by measuring the NPs surface charge (-19.2 mV) by zeta potential analysis (ζ). The green-synthesized Ag-NPs exhibited broad-spectrum antibacterial activity at different concentrations (6.25-100 ppm) against the pathogens Staphylococcus aureus, Bacillus subtilis Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium with a clear inhibition zone ranging from (9.5 ± 0.4) nm to (21.7 ± 1.0) mm. Furthermore, the green-synthesized Ag-NPs displayed high efficacy against the Caco-2 cancerous cell line (the half maximal inhibitory concentration (IC50) = 5.7 ± 0.2 ppm). With respect to antibacterial and in-vitro cytotoxicity analyses, the Ag-NPs concentration of 100 ppm was selected as a safe dose for loading onto cotton fabrics. The scanning electron microscopy connected with energy-dispersive X-ray spectroscopy (SEM-EDX) for the nano-finished fabrics showed the distribution of Ag-NPs as 2% of the total fabric elements. Moreover, the nano-finished fabrics exhibited more activity against pathogenic Gram-positive and Gram-negative bacteria, even after 10 washing cycles, indicating the stability of the treated fabrics.

Rhizophagus irregularis and Rhizoctonia solani Differentially Elicit Systemic Transcriptional Expression of Polyphenol Biosynthetic Pathways Genes in Sunflower.

Plant roots are exposed to penetration by different biotrophic and necrotrophic fungi. However, plant immune responses vary, depending on the root-penetrating fungus. Using qRT-PCR, changes over time in the systemic transcriptional expression of the polyphenol biosynthesis-related genes were investigated in sunflower plants in response to colonization with Rhizophagus irregularis and/or infection with Rhizoctonia solani. The results demonstrated that both fungi systemically induced the transcriptional expression of most of the addressed genes at varying degrees. However, the inducing effect differed according to the treatment type, plant organ, targeted gene, and time stage. The inducing effect of R. irregularis was more prevalent than R. solani in the early stages. In general, the dual treatment showed a superior inducing effect over the single treatments at most of the time. The hierarchical clustering analysis showed that cinnamate-4-hydroxylase was the master expressed gene along the studied time period. The cell wall lignification was the main plant-defensive-mechanism induced. In addition, accumulations of chlorogenic acid, flavonoids, and anthocyanins were also triggered. Moreover, colonization with R. irregularis improved the plant growth and reduced the disease severity. We can conclude that the proactive, rather than curative, colonization with R. irregularis is of great importance, owing to their protective and growth-promoting roles, even if no infection occurred.

Phytochemical Screening and Antiprotozoal Effects of the Methanolic Berberis vulgaris and Acetonic Rhus coriaria Extracts.

Berberis vulgaris (B. vulgaris) and Rhus coriaria (R. coriaria) have been documented to have various pharmacologic activities. The current study assessed the in vitro as well as in vivo inhibitory efficacy of a methanolic extract of B. vulgaris (MEBV) and an acetone extract of R. coriaria (AERC) on six species of piroplasm parasites. The drug-exposure viability assay was tested on three different cell lines, namely mouse embryonic fibroblast (NIH/3T3), Madin-Darby bovine kidney (MDBK) and human foreskin fibroblast (HFF) cells. Qualitative phytochemical estimation revealed that both extracts containing alkaloid, tannin, saponins and terpenoids and significant amounts of flavonoids and polyphenols. The GC-MS analysis of MEBV and AERC revealed the existence of 27 and 20 phytochemical compounds, respectively. MEBV and AERC restricted the multiplication of Babesia (B.) bovis, B. bigemina, B. divergens, B. caballi, and Theileria (T.) equi at the half-maximal inhibitory concentration (IC50) of 0.84 ± 0.2, 0.81 ± 0.3, 4.1 ± 0.9, 0.35 ± 0.1 and 0.68 ± 0.1 µg/mL and 85.7 ± 3.1, 60 ± 8.5, 90 ± 3.7, 85.7 ± 2.1 and 78 ± 2.1 µg/mL, respectively. In the cytotoxicity assay, MEBV and AERC inhibited MDBK, NIH/3T3 and HFF cells with half-maximal effective concentrations (EC50) of 695.7 ± 24.9, 931 ± 44.9, ˃1500 µg/mL and 737.7 ± 17.4, ˃1500 and ˃1500 µg/mL, respectively. The experiments in mice showed that MEBV and AERC prohibited B. microti multiplication at 150 mg/kg by 66.7% and 70%, respectively. These results indicate the prospects of these extracts as drug candidates for piroplasmosis treatment following additional studies in some clinical cases.

Serratia marcescens BM1 Enhances Cadmium Stress Tolerance and Phytoremediation Potential of Soybean Through Modulation of Osmolytes, Leaf Gas Exchange, Antioxidant Machinery, and Stress-Responsive Genes Expression.

The heavy metal contamination in plant-soil environment has increased manifold recently. In order to reduce the harmful effects of metal stress in plants, the application of beneficial soil microbes is gaining much attention. In the present research, the role of Serratia marcescens BM1 in enhancing cadmium (Cd) stress tolerance and phytoremediation potential of soybean plants, was investigated. Exposure of soybean plants to two Cd doses (150 and 300 µM) significantly reduced plant growth, biomass, gas exchange attributes, nutrients uptake, antioxidant capacity, and the contents of chlorophyll, total phenolics, flavonoids, soluble sugars, and proteins. Additionally, Cd induced the stress levels of Cd, proline, glycine betaine, hydrogen peroxide, malondialdehyde, antioxidant enzymes (i.e., catalase, CAT; ascorbate peroxidase, APX; superoxide dismutase, SOD; peroxidise, POD), and the expression of stress-related genes (i.e., APX, CAT, Fe-SOD, POD, CHI, CHS, PHD2, VSO, NR, and P5CS) in soybean leaves. On the other hand, inoculation of Cd-stressed soybean plants with Serratia marcescens BM1 significantly enhanced the plant growth, biomass, gas exchange attributes, nutrients uptake, antioxidant capacity, and the contents of chlorophyll, total phenolics, flavonoids, soluble sugars, and proteins. Moreover, Serratia marcescens BM1 inoculation reduced the levels of cadmium and oxidative stress markers, but significantly induced the activities of antioxidant enzymes and the levels of osmolytes and stress-related genes expression in Cd-stressed plants. The application of 300 µM CdCl2 and Serratia marcescens triggered the highest expression levels of stress-related genes. Overall, this study suggests that inoculation of soybean plants with Serratia marcescens BM1 promotes phytoremediation potential and Cd stress tolerance by modulating the photosynthetic attributes, osmolytes biosynthesis, antioxidants machinery, and the expression of stress-related genes.

Exogenous Nitric Oxide Mitigates Nickel-Induced Oxidative Damage in Eggplant by Upregulating Antioxidants, Osmolyte Metabolism, and Glyoxalase Systems.

Nitric oxide (NO) at optimal levels is considered beneficial to plant functioning. The present study was carried out to investigate the role of exogenously applied NO (100 and 150 µM sodium nitropurusside, SNP) in amelioration of nickel (Ni)-mediated oxidative effects in eggplant. Ni stress declined growth and biomass production, relative water content (RWC), and chlorophyll pigment synthesis, thereby affecting the photosynthetic efficiency. Exogenously applied SNP proved beneficial in mitigating the Ni-mediated growth restrictions. NO-treated seedlings exhibited improved photosynthesis, stomatal conductance, and chlorophyll content with the effect of being apparent at lower concentration (100 µM SNP). SNP upregulated the antioxidant system mitigating the oxidative damage on membranes due to Ni stress. The activity of superoxide dismutase, catalase, glutathione S-transferase, ascorbate peroxidase, and glutathione reductase was upregulated due to SNP which also increased the ascorbate and reduced glutathione content. SNP-supplied seedlings also showed higher proline and glycine betaine accumulation, thereby improving RWC and antioxidant system. Glyoxalase I activity was induced due to SNP application declining the accumulation of methylglyoxal. NO-mediated mitigation of Ni toxicity was confirmed using NO scavenger (PTIO, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), which reversed the influence of SNP almost entirely on the parameters studied. Uptake of nitrogen (N), potassium (K), and calcium (Ca) was increased due to SNP application and Ni was reduced significantly. Therefore, this study revealed the efficiency of exogenous SNP in enhancing Ni stress tolerance through upregulating antioxidant and glyoxalase systems.

Changes in Ecophysiology, Osmolytes, and Secondary Metabolites of the Medicinal Plants of Mentha piperita and Catharanthus roseus Subjected to Drought and Heat Stress.

Global warming contributes to higher temperatures and reduces rainfall for most areas worldwide. The concurrent incidence of extreme temperature and water shortage lead to temperature stress damage in plants. Seeking to imitate a more natural field situation and to figure out responses of specific stresses with regard to their combination, we investigated physiological, biochemical, and metabolomic variations following drought and heat stress imposition (alone and combined) and recovery, using Mentha piperita and Catharanthus roseus plants. Plants were exposed to drought and/or heat stress (35 °C) for seven and fourteen days. Plant height and weight (both fresh and dry weight) were significantly decreased by stress, and the effects more pronounced with a combined heat and drought treatment. Drought and/or heat stress triggered the accumulation of osmolytes (proline, sugars, glycine betaine, and sugar alcohols including inositol and mannitol), with maximum accumulation in response to the combined stress. Total phenol, flavonoid, and saponin contents decreased in response to drought and/or heat stress at seven and fourteen days; however, levels of other secondary metabolites, including tannins, terpenoids, and alkaloids, increased under stress in both plants, with maximal accumulation under the combined heat/drought stress. Extracts from leaves of both species significantly inhibited the growth of pathogenic fungi and bacteria, as well as two human cancer cell lines. Drought and heat stress significantly reduced the antimicrobial and anticancer activities of plants. The increased accumulation of secondary metabolites observed in response to drought and/or heat stress suggests that imposition of abiotic stress may be a strategy for increasing the content of the therapeutic secondary metabolites associated with these plants.

Melatonin and Its Protective Role against Biotic Stress Impacts on Plants.

Biotic stress causes immense damage to agricultural products worldwide and raises the risk of hunger in many areas. Plants themselves tolerate biotic stresses via several pathways, including pathogen-associated molecular patterns (PAMPs), which trigger immunity and plant resistance (R) proteins. On the other hand, humans use several non-ecofriendly methods to control biotic stresses, such as chemical applications. Compared with chemical control, melatonin is an ecofriendly compound that is an economical alternative strategy which can be used to protect animals and plants from attacks via pathogens. In plants, the bactericidal capacity of melatonin was verified against Mycobacterium tuberculosis, as well as multidrug-resistant Gram-negative and -positive bacteria under in vitro conditions. Regarding plant-bacteria interaction, melatonin has presented effective antibacterial activities against phytobacterial pathogens. In plant-fungi interaction models, melatonin was found to play a key role in plant resistance to Botrytis cinerea, to increase fungicide susceptibility, and to reduce the stress tolerance of Phytophthora infestans. In plant-virus interaction models, melatonin not only efficiently eradicated apple stem grooving virus (ASGV) from apple shoots in vitro (making it useful for the production of virus-free plants) but also reduced tobacco mosaic virus (TMV) viral RNA and virus concentration in infected Nicotiana glutinosa and Solanum lycopersicum seedlings. Indeed, melatonin has unique advantages in plant growth regulation and increasing plant resistance effectiveness against different forms of biotic and abiotic stress. Although considerable work has been done regarding the role of melatonin in plant tolerance to abiotic stresses, its role in biotic stress remains unclear and requires clarification. In our review, we summarize the work that has been accomplished so far; highlight melatonin's function in plant tolerance to pathogens such as bacteria, viruses, and fungi; and determine the direction required for future studies on this topic.

Genetic Transformation and Hairy Root Induction Enhance the Antioxidant Potential of Lactuca serriola L.

Lactuca serriola L. is a herbaceous species, used for human nutrition and medicinal purposes. The high antioxidant capacity of L. serriola indicates the possibility of enhancing its edible and health potential by increasing the flavonoid and phenolic contents. The present study aimed at enhancing the production of phenolics and flavonoids by hairy root cultures in Lactuca serriola transformed with Agrobacterium rhizogenes strain AR15834 harbouring the rolB gene. The genetic transformation of rolB in transformed roots was validated, and rolB expression level was evaluated using real-time qPCR analysis. Expression levels of flavonoid biosynthesis genes (CHI, PAL, FLS, and CHS) were assessed in the hairy and nontransformed roots. Results showed higher expression levels in the transgenic roots than in the nontransformed ones (p < 0.01). Transgenic hairy roots exhibited a 54.8-96.7% increase in the total phenolic content, 38.1-76.2% increase in the total flavonoid content, and 56.7-96.7% increase in the total reducing power when compared with the nontransgenic roots (p < 0.01). DPPH results also revealed that the transgenic hairy roots exhibited a 31.6-50% increase in antioxidant potential, when compared to normal roots. This study addressed the enhancement of secondary metabolite biosynthesis by hairy root induction in L. serriola.