Vicia Faba Seedlings Research Articles

The application of PAHs-Degrading Pseudomonas aeruginosa to mitigate the phytotoxic impact of pyrene on barley (Hordeum vulgare L.) and broad bean (Vicia faba L.) plants

Mitigating the negative impacts of polycyclic aromatic hydrocarbons (PAHs) is an urgent need due to their toxicity and persistence in the environment. This study investigated the use of Pseudomonas aeruginosa ASU-B6 to detoxify pyrene (PY). The bacterium P. aeruginosa ASU-B6 is capable of degrading PY by 92% as a sole carbon source after 15 days of incubation with phthalate being the major metabolic product. In this regard, the impact of pyrene (PY), P. aeruginosa ASU-B6 (ASU-B6), the bacterial strain combined with pyrene (ASU-B6/PY) and the metabolites produced after pyrene degradation (PY-metabolites) on the germination and physiological attributes of Hordeum vulgare and Vicia faba seedlings were studied. A single application of PY or ASU-B6 showed a toxic effect on the germination of both tested seeds. Interestingly, broad bean seedlings exhibited less sensitivity to PY stress in terms of growth and metabolism compared to barley. Notably, ASU-B6 inhibited fresh and dry weight of shoots and roots of barley and, to a lesser extent, reduced the germination of broad beans compared to the control. However, the combined PY-metabolites and ASU-B6/PY showed a mutual ameliorative effect on seedlings growth, alleviating the phytotoxic impact of each component. Pyrene reduced the virulence of ASU-B6 by inhibiting the production of pyocyanin pigment, while bacteria ameliorated pyrene toxicity through its degradation. Heatmap and principal component analyses highlighted that increasing the contents of hydrogen peroxide, superoxide anion, hydroxyl radical, and lipid peroxidation positively correlated to the toxicity of PY or ASU-B6. However, improving the antioxidant system which buffers the oxidative stress induced by different combinations of PY and ASU-B6 enhanced the growth of germinated seedlings corresponding to PY or ASU-B6. This study reflected the role of ASU-B6 in ameliorating PY-phytotoxicity. In addition, the application of ASU-B6 strain is recommended as a prospective candidate for remediation of PAHs-contaminated environment with a positive impact on the plant growth and metabolic products.

Plant-associated halotolerant bacteria improving growth of Vicia faba L. Mariout-2 under salinity conditions

In this comprehensive investigation, we successfully isolated and characterized 40 distinct plant-associated halotolerant bacteria strains obtained from three halophytic plant species: Tamarix nilotica, Suaeda pruinosa, and Arthrocnemum macrostachyum. From this diverse pool of isolates, we meticulously selected five exceptional plant-associated halotolerant bacteria strains through a judiciously designed seed biopriming experiment and then identified molecularly. Bacillus amyloliquefaciens DW6 was isolated from A. macrostachyum. Three bacteria (Providencia rettgeri DW3, Bacillus licheniformis DW4, and Salinicoccus sesuvii DW5) were isolated for the first time from T. nilotica, S. pruinosa and S. pruinosa, respectively. Paenalcaligenes suwonensis DW7 was isolated for the first time from A. macrostachyum. These plant-associated halotolerant bacteria exhibited growth-promoting activities, including phosphate solubilization, nitrogen fixation, and production of bioactive compounds, i.e., ammonia, phytohormones, hydrogen cyanide, siderophores, and exopolysaccharides. A controlled laboratory experiment was conducted to reduce the detrimental impact of soil salinity. Vicia faba seedlings were inoculated individually or in mixtures by the five most effective plant-associated halotolerant bacteria to reduce the impact of salt stress and improve growth parameters. The growth parameters were significantly reduced due to the salinity stress in the control samples, compared to the experimental ones. The unprecedented novelty of our findings is underscored by the demonstrable efficacy of co-inoculation with these five distinct bacterial types as a pioneering bio-approach for countering the deleterious effects of soil salinity on plant growth. This study thus presents a remarkable contribution to the field of plant science and offers a promising avenue for sustainable agriculture in saline environments.

Green-synthesized zinc oxide nanoparticles by Enterobacter sp.: unveiling characterization, antimicrobial potency, and alleviation of copper stress in Vicia faba (L.) plants

BackgroundThe biosynthesis of zinc oxide nanoparticles (ZnO NPs) using Enterobacter sp. and the evaluation of their antimicrobial and copper stress (Cu+ 2)-reducing capabilities in Vicia faba (L.) plants. The green-synthesized ZnO NPs were validated using X-ray powder diffraction (XRD); Fourier transformed infrared (FTIR), Ultraviolet-Visible spectroscopy (UV-Vis), Transmission electron microscope (TEM) and scanning electron microscopy (SEM) techniques. ZnO NPs could serve as an improved bactericidal agent for various biological applications. as well as these nanoparticles used in alleviating the hazardous effects of copper stress on the morphological and physiological traits of 21-day-old Vicia faba (L.) plants.ResultsThe results revealed that different concentrations of ZnO NPs (250, 500, or 1000 mg L-1) significantly alleviated the toxic effects of copper stress (100 mM CuSO4) and increased the growth parameters, photosynthetic efficiency (Fv/Fm), and pigments (Chlorophyll a and b) contents in Cu-stressed Vicia faba (L.) seedlings. Furthermore, applying high concentration of ZnO NPs (1000 mg L-1) was the best dose in maintaining the levels of antioxidant enzymes (CAT, SOD, and POX), total soluble carbohydrates, total soluble proteins, phenolic and flavonoid in all Cu-stressed Vicia faba (L.) seedlings. Additionally, contents of Malondialdehyde (MDA) and hydrogen peroxide (H2O2) were significantly suppressed in response to high concentrations of ZnO NPs (1000 mg L-1) in all Cu-stressed Vicia faba (L.) seedlings. Also, it demonstrates strong antibacterial action (0.9 mg/ml) against various pathogenic microorganisms.ConclusionsThe ZnO NPs produced in this study demonstrated the potential to enhance plant detoxification and tolerance mechanisms, enabling plants to better cope with environmental stress. Furthermore, these nanoparticles could serve as an improved bactericidal agent for various biological applications.

Efficient Role of Endophytic Aspergillus terreus in Biocontrol of Rhizoctonia solani Causing Damping-off Disease of Phaseolus vulgaris and Vicia faba.

The wide spread of plant pathogens affects the whole world, threatening national food security. Various fungi including Rhizoctonia solani induce the fungal disease damping-off that negatively affects plant seedlings' growth. Recently, endophytic fungi are used as safe alternatives to chemical pesticides that harm plant and human health. Here, an endophytic Aspergillus terreus was isolated from Phaseolus vulgaris seeds to control damping-off diseases by improving the defense system in Phaseolus vulgaris and Vicia faba seedlings. Endophytic fungus was morphologically and genetically identified Aspergillus terreus, and it is deposited in GeneBank under accession OQ338187. A. terreus demonstrated antifungal efficacy against R. solani with an inhibition zone at 22.0 mm. Moreover, the minimum inhibitory concentrations (MIC) of ethyl acetate extract (EAE) of A. terreus were between 0.3125 and 0.625 mg/mL to inhibit R. solani growth. Precisely 58.34% of the Vicia faba plants survived when A. terreus was added compared with the untreated infected (16.67%). Similarly, Phaseolus vulgaris achieved 41.67% compared to the infected (8.33%). Both groups of treated infected plants showed reduced oxidative damage (reduced Malondialdehyde and hydrogen peroxide levels) as compared to untreated infected plants. Reduced oxidative damage was correlated with the increase in photosynthetic pigments and the antioxidant defense system including polyphenol oxidase, peroxidase, catalase, and superoxide dismutase enzyme activities. Overall, the endophytic A. terreus can be considered an effective tool to control the suppression of Rhizoctonia solani in legumes, especially Phaseolus vulgaris and Vicia faba, as an alternative to synthetic chemical pesticides that harm the environment and human health.

Effects of strontium on the morphological and photosynthetic physiological characteristics of Vicia faba seedlings

The adaptation of plants to strontium (Sr) stress requires a more systematic understanding. In the present study, the morphological and photosynthetic physiological characteristics of Vicia faba seedlings under Sr stress (88Sr, 0–1,000 mg·L−1) were analyzed in solution culture. The results showed that Sr treatment decreased the biomass and root activity of V. faba seedlings significantly, but fortunately, there was almost no root necrosis. In plant morphology, the taproot length, lateral root number, plant height, branching number and internodes number of V. faba were significantly inhibited, thus the apical dominance of taproot and terminal bud was more obvious. The accumulation of Sr resulted in the decrease of leaf area, dry weight, stomatal density and stomatal aperture, while the guard cell length increased, and the specific leaf weight (SLW) increased first and then decreased. These changes in stomatal morphology may be a positive regulation to reduce water loss. In addition, V. faba increased the non-photochemical quenching (NPQ) and the activities of peroxidase (POD) and ascorbate peroxidase (APX) to protect the photosynthetic structure. Low concentration of Sr (250 mg·L−1) promoted the photochemical efficiency and electron transfer of PSII (e.g., increased F v/F m, Φ PSII, qP and ETR). However, Sr (250–1,000 mg·L−1) inhibited the net photosynthetic rate (P n), transpiration rate (T r) and stomatal conductance (G s) in leaves. In general, the P n was affected by both stomatal and non-stomatal factors. Since Sr did not cause significant damage to the PSII function, the non-stomatal factor may be the dark reaction in photosynthesis affected, but this needs to be proved by further studies.

Simultaneous biodegradation of \u03bb-cyhalothrin pesticide and Vicia faba growth promotion under greenhouse conditions

λ-cyhalothrin is a widely used synthetic pyrethroid insecticide and its persistence in plant, soil and water exerts a detrimental effect on humans as well as the environment. There are many studies regarding isolated bacteria capable of degrading λ-cyhalothrin in vitro. However, limited work has been done examining the microbial degradation of λ-cyhalothrin together with plant growth promotion under greenhouse conditions. In this study, 43 bacterial strains were isolated from heavily polluted soil with λ-cyhalothrin by the enrichment technique. The plant growth promotion characteristics of all isolates were evaluated. The results revealed that five isolates were potential in λ-cyhalothrin biodegradation at high concentration (1200 mg/L) within only 24 h together with their high plant growth promotion abilities. The morphological, biochemical and 16S rDNA sequence analyses identified the isolates as Bacillus subtilis strains. The GC/MS analysis revealed that the selected isolates reached high levels of degradation after only two days, the degradation percentage ranged from 95.72 to 99.52% after 48 h of incubation. Furthermore, the degradation pathway for complete detoxification and metabolism of λ-cyhalothrin was established. Moreover, greenhouse experiment was conducted, the results indicate that the application of seed coat significantly enhanced Vicia faba seedling growth and caused an increase from 38.4 to 40.2% percentage of fresh and dry weight, respectively compared to untreated control. All isolates were effective to remove the pesticide residues in Vicia faba seedlings and recorded the highest degradation percentage of 83.79 under greenhouse conditions. Therefore, it can be concluded that the Bacillus subtilis strains isolated in this study have a dual potential role in complete mineralization of λ-cyhalothrin residues in vivo as well as effective biofertilization for future use in sustainable agriculture.

Vicia-Micronucleus Test Application for Saline Irrigation Water Risk Assessment.

In view of climate change, increasing soil salinity is expected worldwide. It is therefore important to improve prediction ability of plant salinity effects. For this purpose, brackish/saline irrigation water from two areas in central and coastal Tunisia was sampled. The water samples were classified as C3 (EC: 2.01–2.24 dS m−1) and C4 (EC: 3.46–7.00 dS m−1), indicating that the water was questionable and not suitable for irrigation, respectively. The water samples were tested for their genotoxic potential and growth effects on Vicia faba seedlings. Results showed a decrease in mitotic index (MI) and, consequently, growth parameters concomitant to the appearance of micronucleus (MCN) and chromosome aberrations when the water salinity increased. Salt ion concentration had striking influence on genome stability and growth parameters. Pearson correlation underlined the negative connection between most ions in the water inappropriate for irrigation (C4) and MI as well as growth parameters. MI was strongly influenced by Mg2+, Na+, Cl−, and to a less degree Ca2+, K+, and SO42−. Growth parameters were moderately to weakly affected by K+ and Ca2+, respectively. Re-garding MCN, a very strong positive correlation was found for MCN and K+. Despite its short-term application, the Vicia-MCN Test showed a real ability to predict toxicity induced by salt ions confirming that is has a relevant role in hazard identification and risk assessment of salinity effects.

Municipal solid waste landfill leachate induced cytotoxicity in root tips of Vicia faba: Environmental Risk posed by non-engineered landfill

Landfills are considered the main option for dumping of municipal solid waste (MSW) all over the world, but these landfills are mostly non-engineered. The decomposition of solid waste in the landfill and rainwater penetration into the decomposing waste produces leachate that contains dissolved organic and inorganic compounds, heavy metals, suspended particles, and hazardous substances. Leachate migration in the environment may pose serious health risks to organisms exposed. Hence, the present study explored the cytotoxic potential of landfill leachate collected in different seasons from the Okhla landfill site, Delhi, India. Cytotoxicity of leachate samples was evaluatedby cell apoptosis and ultrastructural observation based on Transmission Electron Microscopy (TEM) of the cells of root tips of vicia faba seedlings treated with the leachates collected in summer, winter and monsoon in a time and dose dependent manner. Leachate collected in all the three seasons induced apoptosis in cells of root tips of vicia faba that increased in a time and dose dependent manner when compared to control. The apoptosis was highest in the samples treated with leachate collected in the summer season, followed by winter and monsoon. It was further confirmed with TEM images that there was induction of apoptotic-like morphological changes in the root cells treated with landfill leachate when compared with the control. The present study indicates that municipal solid waste leachate is very toxic and it should be treated before disposing it to the environment.

Phytotoxicity mechanism of the natural radionuclide thorium in Vicia faba

Elucidation of the phytotoxic mechanisms of thorium (Th) is important for controlling Th accumulation in crops and improving the efficiency of phytoremediation. Here, we analyzed the subcellular distribution of Th in Vicia faba seedlings and the toxic reaction of seedlings to Th (5–40 μmol·L−1) at the subcellular and cellular levels. Increasing the phosphate level in the culture medium from 0.01 to 0.1 mmol·L−1 decreased the Th accumulation by the roots by 47–57%. Th was mainly distributed in the root cell walls (94–96%) and existed mainly in the form of residue (92–94%). Th accumulation in the root was similar to the changes observed for P, Ni, Cu, and Fe. High concentrations of Th (40 μmol·L−1) induced abnormal root growth and leaf photosynthetic metabolism. At the cellular level, Th (40 μmol·L−1) induced root edge cell death and inhibited root respiration and cell mitosis. SOD, POD and CAT activities were involved in the regulation of reactive oxygen species accumulation in the roots. Untargeted metabolomics identified 580 and 262 differentially expressed metabolites in roots and leaves. At the metabolic level, its toxicological mechanism involved a severe inhibition of the expression of nucleotides in roots and leaves.

Mycogenic Nano-Complex for Plant Growth Promotion and Bio-Control of Pythium aphanidermatum.

(1) Background: biological way is one of the most ecofriendly and safe strategies for nanomaterials synthesis. So, biosynthesis-green method was used for the preparation of Zn(II) complex (in the Nano scale) from the reaction of the schiff base ligand 2,2′-((1E,1′E)-(1,2-phenylenebis (azanylylidene)), bis(methanylylidene))bis(4-bromophenol), and Zn(II)sulphate. The biogenic ZnNP-T was characterized by different methods. Our purpose was to evaluate the ability of biosynthesis-green method for the preparation of Zn(II) complex as an antifungal agent against diseases from fungal species. (2) Methods: in this work, isolates of Pythium aphanidermatum and Trichderma longibrachiatum were obtained, and Trichderma longibrachiatum was used to prepare nano metal complex. We tested the pathogenicity of nano metal complex against seedling and germination of seeds, and we evaluated the effectiveness of ZnNP-T for growth promotion of Vicia feba in early stage and inhibitory activity against Pythium aphanidermatum. (3) Results: antagonistic activity of ZnNP-T was tested in vitro against Pythium aphanidermatum, and then the growth rates of Vicia faba were determined. The obtained data revealed that mycelial growth of pathogenic fungus was inhibited about 73.8% at 20 ppm. In addition, improved the total biomass of Vicia faba in the presence of P. aphanidermatum. All concentration of ZnNP-T positively affected root weight of Vicia faba seedlings, and positively affected shoot weight. Root and shoot lengths were affected by using 20 ppm of ZnNP-T with up to 180 and 96.5 mm of shoot and root length compared to that of the control, while germination percentage was significantly enhanced with up to 100% increase after 72 h of germination. (4) Conclusion: one of the modern challenges in vegetable or fruit production is to enhance seed germination and to grow healthy plants with strong root system. In future, there should be a focus on using of biogenic Zinc nano-complex as plant growth promoter agents.

Protists modulate Fusarium root rot suppression by beneficial bacteria

Plant health largely depends on root-associated microorganisms that inhibit pathogens. Enriching the rhizosphere microbiome with beneficial bacteria has a high potential of supporting future sustainable food production. However, the introduced microorganisms often show low activity with a low survival rate. We propose to solve this limitation by co-inoculating beneficial bacteria with protists. Free-living protists are one of the main regulators of bacterial activity in the rhizosphere and can increase the density and activity of pathogen-suppressive microbes. We therefore hypothesized that protist-bacteria interactions may serve to enhance plant protection against soil-borne pathogens. We tested whether co-inoculating beneficial bacteria with protists increases plant protection against Fusarium solani S55, a fungal pathogen causing root rot. We inoculated Vicia faba seedlings with the disease-suppressing bacteria Rahnella aquatilis B16C and Pseudomonas yamanorum B12, alone or in combination with three different bacterivorous soil protists, Rosculus terrestris S14D1, Bodomorpha sp. C10D3 and Cercomonas lenta C5D5. We grew plants in Fusarium-infested soil and recorded the effect of inoculation on disease severity and pathogen density. We demonstrated that introduced bacteria and protists synergistically impact plant health. When introduced alone, both bacteria and protists provided a partial protection against Fusarium rot. Protists further modulated the performance of the bacteria in an idiosyncratic way, with some combinations offering an almost complete Fusarium solani S55 suppression.These results suggest that protists could form the base of a new generation of biological control strategies of soil-borne diseases, either as a standalone inoculant or as an enhancer of beneficial bacteria.

Morphological, molecular characterization, plant pathogenicity and biocontrol of Cladosporium complex groups associated with faba beans

Vicia faba (faba bean) is one of the most significant leguminous crops. The faba bean is specialized by maximum nutritional value, in energy and protein content, which leads it to be suitable for food and feed production. Diseases caused with fungi are amongst the biotic factors responsible for decreasing in faba bean yields. In this work, Cladosporium isolates were recorded in cultivated faba bean leaves and pods collected from markets in Qena, Upper Egypt; morphological features and molecular characterization based on actin gene were performed. The ability of the pathogens to cause disease in faba bean seedlings and the biocontrol method to avoid the pathogenic effect of Cladosporium were determined. Results showed that Cladosporium is the main genera isolated from faba beans, and the morphological criteria showed presence of three species complex groups of Cladosporium (C. cladosporioides, C. herbarum and C. sphaerospermum) and the confirmation with molecular characterization revealed the existence of four species in the three groups. All the 26 tested strains of Cladosporium were able to cause leaf lesions on Vicia faba seedlings with different levels. Chaetomium globosum is a biocontrol agent could inhibit the growth of the majority strains of Cladosporium.

Effect of Tebuconazole on Growth Processes, Content and Redistribution of Carbohydrates in Horse Bean Seedlings under Scotomorphogenesis

The article presents a study of changes in the functioning of the source-sink system in the heterotrophic phase of development of horse beans (Vicia faba L.) under the conditions of the artificial combination of external (darkness) factor and internal factor (antigiberelline retardant) during germination. It was found that the action of the drug significantly reduced the length of the epicotyl, root and total seedling. Similarly, the dry matter mass of the seedling organs decreased. The level of using seed spare substances under the influence of retardant decreased, as evidenced by the maximum dry matter of cotyledons in plants of this variant and a decrease in the utilization of reserve substances for root and epicotyl formation during germination. Tebuconazole inhibited the breakdown of starch in the dark. The higher content of sugars in the seeds of scotomorphic plants in comparison with the control is associated with a less intensive outflow for the needs of organogenesis – the formation of root and epicotyl structures. Quantitative changes in nitrogen content in scotomorphic seeds were much smaller than changes in starch content. This indicates that the retardant in the dark inhibits the hydrolysis of the reserve protein of the seed, but the process is started after the hydrolysis of starch. The purpose of the study was to establish the effect of tebuconazole on the processes of germination and redistribution of carbohydrates in seedlings of Vicia faba L. Material and methods. The work was carried out on seedlings of horse beans (Vicia faba L.) of Vivat variety, which is a medium-ripe high-yielding variety with a vegetation period of 100-105 days. The variety is technological, resistant to major diseases, has high resistance to lodging, shedding of beans and their cracking. Results and discussion. The combined effect of darkness and the drug of anti-gibberellin action of tebuconazole were used to regulate the intensity of source-sink relations during the germination of horse bean seeds. The seeds of the experimental variant were soaked for a day in 0.5% solution of the triazole-derived drug tebuconazole. Tebuconazole is a transparent crystalline substance of hazard class 3. The seeds of the control variant were soaked for 24 hours in distilled water and sown in cuvettes with wet sand. The biological replication of the experiments is fivefold. The experiment was performed under the action of light and in dark in order to study the implementation of programs of skoto-and photomorphogenesis. Morpho-biometric parameters (root length, seedling length, dry matter weight of individual organs and the whole plant) were determined on the day of 18 of germination. Determination of nitrogen content was carried out according to Keldal method, starch in the organs of seedlings was performed by iodometric method, to determine the content of total sugar and reducing sugar we used Bertrand method in modification by V. Kosolapov. Conclusion. The combination of exogenous and endogenous factors during seed germination significantly changed the intensity of donor-acceptor relations in horse bean seedlings. Under the action of the drug significantly slowed the growth of seedlings in the dark. There was the decrease in the dry matter of the organs of the seedling in dark and noted lower rates of use of reserve substances for organogenesis during germination

Unraveling response mechanism of photosynthetic metabolism and respiratory metabolism to uranium-exposure in Vicia faba

As a natural radionuclide, uranium (U) has obvious phytotoxicity, the purpose of this study is to unravel the response mechanism of U on photosynthetic and respiratory metabolism in plants. Therefore, 14-day-old Vicia faba seedlings were exposed to 0–25 μM U during 72 h. U effects on growth parameters, physiological parameters of plants, and potential phytotoxicity mechanism were investigated by physiological analysis, and metabolome and transcriptome data. U significantly inhibited photosynthesis and respiration of plants. In metabolome analysis, 53 metabolites related to carbohydrate metabolism were identified (13 up-regulated, 12 down-regulated). In transcriptome analysis, U significantly inhibited the expression of photoreactive electron transport chain (up: 0; down: 31), Calvin cycle (up: 0; down: 12) and photorespiration pathway genes (up: 0; down: 8). U significantly inhibited the expression of cellular energy metabolic pathways genes (e.g., glycolysis, TCA cycle, and oxidative phosphorylation pathways) (up 8, down 18). We concluded that U inhibited the expression of genes involved in the photosynthetic metabolic pathway, which caused the decrease of photosynthetic rate. Meanwhile, U inhibited the expression of the electron transport chain genes in the mitochondrial oxidative phosphorylation pathway, which leads to the abnormal energy supply of cells and the inhibition of root respiration rate.

Genotoxicity response of Vicia faba seedlings to cadmium in soils as characterized by direct soil exposure and micronucleus test.

To overcome the drawbacks of the Vicia faba root tip micronucleus test in soil using the solution extract method, we conducted a potting experiment by direct soil exposure. Cadmium was spiked into 3 typical soils (brown soil, red soil, and black soil) to simulate environmental concentrations (0.625, 1.25, 2.5, 5, and 10 mg kg-1). Multiple Vicia faba tissues (primary root tips, secondary root tips, and leaf tips) were sampled, and mitotic index (MI), chromosome aberration frequency (CA), and micronucleus frequency (MN) were used as endpoints after a seedling period of 5 days. The results showed a response between Cd concentrations and multiple sampling tissues of Vicia faba, and the secondary root tips responded to Cd stress the most, followed by primary root tips and leaf tips. Soil physicochemical properties (e.g., pH, total phosphorus, total organic carbon, etc.) influenced the genotoxicity of Cd, and pH was the dominant factor, which resulted in the genetic toxicity response of Cd in soils in the order: red soil > brown soil > black soil. The lowest observable effect concentration (LOEC) of Cd was 1.25 mg kg-1 for both brown soil and red soil and 2.5 mg kg-1 for black soil. In view of this, we suggested that soil properties should be considered in evaluating genotoxicity risk of Cd in soil, especially with soil pH range, and the secondary root tips should be taken as suitable test tissues in the MN test due to its more sensible response feature to Cd stress in soil.

Toxicity Evaluation of Three Imidazolium-based ionic liquids ([C6mim]R) on Vicia faba Seedlings Using an integrated biomarker response (IBR) index

Ionic liquids (ILs) are regarded as green solvents and are frequently used in the chemical industry. However, ILs may impact plant growth if they are present in the soil environment. To compare toxicity of ILs with different anions in soil, three imidazolium-based ionic liquids (1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium nitrate, 1-hexyl-3-methylimidazolium tetrafluoroborate) were used to assess impact on Vicia faba. Following 10 d of exposure to these three ILs from 0 to 2500 mg kg-1, shoot length, root length and dry weight of Vicia faba were determined. Pot trials revealed that ILs inhibited Vicia faba growth and according to EC50 values, [C6mim]BF4 was the most toxic one. In addition, physiological indicators of Vicia faba were determined following 10 d of exposure at selected IL concentrations (0, 1, 10, 100 and 500 mg kg-1). ILs led to the generation of reactive oxygen species and then caused oxidative damage, including lipid peroxidation, protein damage and DNA damage, which triggered an increase in antioxidant content and enzyme activity. The experimental results indicated that oxidative stress may be the primary underlying toxic mechanism for Vicia faba. Furthermore, based on the data of physiological experiment, integrated biomarker response (IBR) was calculated to compare the toxicity of the three ILs and toxic order was: [C6mim]NO3＜[C6mim]Br＜[C6mim]BF4.

English

Atrazine is a widely used herbicide on many crops and is considered one of water pollutant with approved biological hazards on plants, animals and human. Vicia faba seedlings as a biological system, is used to investigate the genotoxicity of Atrazine. Also, Nano selenium (N-Se), a Nano particle with reactive oxygen species scavenging activity was applied to reduce the genotoxicity of Atrazine. Atrazine treatment at concentration of 35 mg/L is applied. Two concentrations of N–Se (10 and 20 ppm) were used alone and in combination with Atrazine (35 mg/L) in addition to control treatment. Changes in germination percentage, shoot and root length, hydrogen peroxide (H2O2) content, lipid peroxidation product malondialdehyde (MDA), chromosomal aberrations, and mitotic index were determined. Semi quantitative RT-PCR analysis (sqRT-PCR) was applied to investigate associated changes in expression pattern of some stress related genes such as antioxidant enzymes, heat shock proteins (HSP17.9, HSP70.1), photosystem II (PSII) and Metalothioniene (MT). Atrazine treatment recorded the lowest germination percentage and caused a reduction in shoot and root length. Significant increase in H2O2 value, MDA contents, and chromosomal abnormalities percent resulted in Atrazine treatment. Noticeable suppression in expression level of all studied genes was accompanied with Atrazine treatment. N–Se, in its two concentrations with Atrazine causing a reduction in all severe effects of Atrazine and improving seedlings performance. Treatments with N–Se induced the expression of MT gene with increase in expression level alongside increase in the concentration of N-Se. This is one of rare studies that investigate the biological effects of N–Se in vivo anti-mutagenesis of Atrazine as well as a first record of Nano metalic particles N–Se as inducer for MT genes. Key words: Nano Selenium, Atrazine, chromosomal aberrations, gene expression, Vicia faba.

Biochemical, Molecular and Mutagenic Effects of Electromagnetic Fields on Vicia faba L. Seedlings

ELECTROMAGNETIC fields (EMFs) consist of two main components electric and magnetic fields. The magnetic fields are the most deleterious and their photons travel in waves-like pattern. These waves penetrate any biological system causing genetic and biochemical changes. In a trail to explore the effects of EMFs on faba bean as a model plant system during seedling stage at cellular, biochemical, and molecular levels, the high-voltage transmission lines as a source of EMFs and aluminum foil as EMFs shelter were used. The effect of EMF direction was investigated by selecting locations at different distances around the high-voltage transmission lines, where seeds were allowed to germinate under different EMF intensities for 10 days. At cellular level, the results showed that EMFs cause severe cytological abnormalities, such as chromosomal breakage, unoriented chromosomes, micronuclei, stickiness, lagging chromosomes, and cytokinesis failure. Such abnormalities were frequent in the Vicia faba seedlings grown directly under the high-voltage transmission lines, where the intensity was 4051μT and the rate of abnormalities increased by decreasing the distance from EMFs source. At biochemical level, Ca2+ binding proteins showed no distinct marker to EMFs, yet arbitrary profiles were observed. At the molecular level, some unique ISSR banding patterns were detected in the EMFs-exposed seedlings. The results indicated no significant differences between the covered and uncovered aluminum foil treatments. Moreover, the plant samples either in the left or right direction exhibited nonsignificant differences. Taken together, these results suggested that a distance of 200 meters from the high-voltage lines is regarded as a safe distance, the effect of EMFs has not inherited in the upcoming generations and aluminum foil cannot protect against EMFs.

Assessing the influence of 1-dodecyl-3-methylimidazolium chloride on soil characteristics and Vicia faba seedlings

Imidazolium-based ionic liquids (ILs) have attracted increasing attention in recent years. The IL 1-dodecyl-3-methylimidazolium chloride ([C12mim]Cl) has been widely used in the chemical industry. In this study, the influence of [C12mim]Cl on Vicia faba seedlings, soil physicochemical properties and soil enzyme activities was investigated for the first time. Meanwhile, the variation of [C12mim]Cl concentrations in soil was monitored during the exposure period. The present results showed that the concentration of [C12mim]Cl remained stable in the tested soil with a change rate of no more than 10% during the exposure period. The 50% effective concentration (EC50) values for shoot length, root length and dry weight were 188, 69 and 132 mg kg−1, respectively. At 200 mg kg−1 and 400 mg kg−1, [C12mim]Cl had significant influence on soil organic matter content, pH value and conductivity value. At 40 mg kg−1, the reactive oxygen species (ROS) levels were obviously enhanced, resulting in oxidative stress effects in Vicia faba seedling leaves. Additionally, the soil enzyme activities changed significantly at 40 mg kg−1.

Stress-Generated Free Radicals Detected by Electron Paramagnetic Resonance Spectroscopy with Nitrone Spin Trap in Vicia faba Root

Electron paramagnetic resonance (EPR) spectroscopy is a promising technique for detection and quantification of short-lived free radicals in biological systems. In the present investigation, root of Viciafaba seedlings were subjected to 0.5 mM (T1) and 1 mM (T2) sodium azide (NaN3) in hydroponic medium. The stress-generated free radicals (superoxide and hydroxyl free radicals) in the root tips of the seedlings were analyzed by EPR spectroscopy using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) nitrone spin. Single cell gel electrophoresis (comet assay) and mitotic index along with the spectrophotometric measurement of the two major antioxidant enzymes, namely, superoxide dismutase (SOD) and catalase (CAT), in combination with analysis of lipid peroxidation product, malondialdehyde (MDA), were done to validate the EPR results. Data obtained from comet assay of root tip cells revealed significant increase in the olive moment in T1 and T2 as compared to control. Decreased mitotic index in T2 (60.63 ± 7.74%) as compared to control (88.23 ± 1.01%) in these cells as a consequence of increased reactive oxygen species (ROS) was depicted. Furthermore, the decrease in the activity of major antioxidant enzymes, SOD and CAT justified the intensified DMPO-OH specific peaks in T2 as compared to control obtained in the EPR spectra. The results establish that EPR spectroscopy can be used successfully at room temperature to monitor changes in the production of free radicals (combined superoxide and hydroxyl free radicals) in plant tissues using DMPO as a spin trap.