In vitro radiation induced alterations in heavy metals and metallothionein content in Plantago ovata Forsk

Combined Effect of Gamma Radiation and Heavy Metals on Some Living Organisms

The purpose of this study was to systematise scientific publications on the combined effect of gamma radiation and heavy metals on living organisms. For this purpose, the method of analysis was applied, by means of which scientific papers in PubMed, Google Scholar, and other related databases were analysed for compliance with the inclusion criteria, where the objects of research were toxic effects of radiation and heavy metals on cells and adaptation processes. The results revealed that the study of the problem was carried out on organisms such as microalgae, fungi, weed and agricultural plants, fish, laboratory rats, and human cell cultures. In most studies, an antagonistic effect between low doses of gamma radiation and heavy metal salts was reported, which was manifested by a reduction in the cytotoxicity of isolated exposure to each agent separately. However, there are studies showing additive effects, especially in heavy metals. At the molecular level, heavy metal accumulation in combination with low doses of radiation (typically defined as less than 0.1 Gy or sievert) induces the expression of metallothionein proteins, which can bind free radicals. At the metabolic level, this is manifested by a decrease in lipid peroxidation products, activation of antioxidant enzymes, and a decrease in apoptosis. The study proved both a direct relationship between zinc and cadmium accumulation in cells and inhibition of caspases and an indirect one, by maintaining mitochondrial membrane integrity through metallothionein.

Recent innovations in fertilization with treated digestate from food waste to recover nutrients for arid agricultural fields

This study aims to explore the development of sustainable fertilizers from waste materials of a biogas plant and a brewery. These wastes, rich in organic carbon and nitrogen, were processed with sulfuric(VI) and phosphoric(V) acid mixture, facilitating the production of free amino acids and achieving waste sanitization. This treatment produced by-products, which extended the range of possible applications. The highest concentration of free amino acids (360 mg/l) was achieved through hydrolyzing with a 40% concentration medium over 24 h. In this case, the maximum levels were recorded for beta-alanine (69.3 mg/l), glycine (46.8 mg/l), isoleucine (43.5 mg/l), proline (36.2 mg/l), and valine (31.5 mg/l). The study presents two fertilizer technologies, with and without micronutrients, that satisfy European Parliament Regulation 2019/1009 (Ntot > 2%, Norg > 0.5%, Corg > 3%). Bioavailability of nutrients in the formulations ranged from 60 to 100%. The efficacies of these fertilizers were evaluated in 30-day pot trials with various plant species, with both single application and fertigation tested. Multielement analysis confirmed high nutrient transfer in the soil-plant system, and the inclusion of micronutrients led to biofortification of plant biomass in Cu (48.3 ± 7.2 mg/kg), Mn (249 ± 37 mg/kg), Zn (164 ± 25 mg/kg), and Fe (211 ± 32 mg/kg). These sustainable fertilizers present an alternative to traditional, non-renewable fertilizers and offer promising solutions for precision agriculture and environmentally conscious production.

Joint effects of gamma radiation and zinc on duckweed Lemna minor L

When assessing the consequences of combined chemical and radiation pollution on bodies of water, it is important to take into account the interaction of different factors, especially the possible synergistic increase in the toxic effect on growth, biochemical and physiological processes of living organisms. In this work, we studied the combined effect of γ-radiation and zinc on freshwater duckweed Lemna minor L. Irradiated plants (doses were 18, 42, and 63 Gy) were placed on a medium with an excess of zinc (3.15, 6.3, 12.6 μmol/L) for 7 days. Our results showed that the accumulation of zinc in tissues increased in irradiated plants when compared to non-irradiated plants. The interaction of factors in assessing their effect on the growth rate of plants was most often additive, but there was also a synergistic increase in the toxic effect at a zinc concentration of 12.6 μmol/L and irradiation at doses of 42 and 63 Gy. When comparing the combined and separate effects of gamma radiation and zinc, it was found that a reduction in the area of fronds (leaf-like plates) was caused exclusively due to the effects of radiation. Zinc and γ-radiation contributed to the enhancement of membrane lipid peroxidation. Irradiation stimulated the production of chlorophylls a and b, as well as carotenoids.

Combined action of gamma radiation and exposure to copper ions on Lemna minor L

PURPOSE

Under natural conditions, the reaction of living organisms to the action of acute gamma radiation depends on other stressors, including heavy metals. The aim of this work was to study changes in morphometric parameters, the content of photoassimilation pigments and the level of oxidative stress in irradiated duckweed at various copper concentrations in the culture medium.

MATERIALS AND METHODS

As a model organism, we used Lemna minor L. Duckweed was exposed to acute γ-radiation at doses of 18, 42, 63 Gy. After irradiation, the plants were transferred into a medium containing 3, 5, 6.3 μmol/L Cu. On the 4th day of exposure, the levels of chlorophyll, carotenoids, malondialdehyde (MDA) were measured; after 7 days, the specific growth rate, the level of damage, the change in the frond area, copper concentration in plant tissues were determined.

RESULTS

The action of γ-radiation (18, 42, 63 Gy) and copper ions (3, 5, 6.3 μmol/L) reduced the growth rate, increased the membrane lipid peroxidation, reduced the area of the fronds more significantly than under the separate action of the factors. The factors acted antagonistically on the specific growth rate. The content of copper in the tissues of irradiated plants (42, 63 Gy) increased.

CONCLUSION

Irradiation of duckweed with acute doses of gamma radiation reduced the resistance of plants to excess copper in the environment.

Molecular cloning, characterization and expression analysis of metallothionein in the liver of the teleost Acrossocheilus fasciatus exposed to cadmium chloride

Metallothionein (MT) has a characteristic molecular structure with a cysteine-rich content. This unique structure provides metal-binding and redox capabilities and promoting metal homeostasis and detoxification in living animals. In order to evaluate the effects of cadmium (Cd) on hepatic MT expression in the liver of Acrossocheilus fasciatus, we obtained the complete cDNA of the A. fasciatus liver MT for the first time. The MT cDNA contains a 605-bp sequence, which codes for 60 amino acids. Protein alignment showed that the similarity between MT protein sequences of A. fasciatus and those of other vertebrates (especially teleosts) was very high and a cysteine residue structure was also conserved. MT was detected in the liver, kidney, gill, testis, muscle, spleen, heart and brain tissues of A. fasciatus by tissue-specific expression analysis. After Cd exposure, Cd/hemoglobin saturation assay, immunohistochemistry and reverse-transcription quantitative PCR (RT-qPCR) were used to describe MT expression in liver tissue. These techniques indicate a sensitive response by liver MT to Cd exposure. The results suggest that A. fasciatus MT may play an important role in the detoxification processes in the liver, and also would be a useful biomarker for monitoring metal pollution in aquatic environments. In addition, A. fasciatus could be regarded as one candidate for a model species for bony fishes in ecotoxicology.

Investigation of the Influence of Selected Soil and Plant Properties from Sakarya, Turkey, on the Bioavailability of Trace Elements by Applying an In Vitro Digestion Model

The main aim of this study was an investigation of the influence of selected soil and plant properties on the bioaccessibility of trace elements and hence their potential impacts on human health in urban environments. Two artificial digestion models were used to determine trace element levels passing from soil and plants to man for bioavailability study. Soil and plant samples were collected from various regions of the province of Sakarya, Turkey. Digestive process is started by addition of soil and plant samples to an artificial digestion model based on human physiology. Bioavailability % values are obtained from the ratio of the amount of element passing to human digestion to element content of soil and plants. According to bioavailability % results, element levels passing from soil samples to human digestion were B = Cr = Cu = Fe = Pb = Li < Al < Ni < Co < Ba < Mn < Sr < Cd < Na < Zn < Tl, while element levels passing from plant samples to human digestion were Cu = Fe = Ni = Pb = Tl = Na = Li < Co < Al < Sr < Ba < Mn < Cd < Cr < Zn < B. It was checked whether the results obtained reached harmful levels to human health by examining the literature.

Metallothionein from Pseudosciaena crocea: expression and response to cadmium-induced injury in the testes

Metallothioneins (MTs) are a family of stress proteins that are involved in the process of detoxification and anti-oxidation. Previous studies have focused mostly on the expression and functions of MTs in the non-reproductive tissues of aquatic vertebrates. However, there have been only a few reports regarding the functions of MTs in the reproductive tissues of such vertebrates. In order to investigate the function of MTs during spermatogenesis in Pseudosciaena crocea, reverse-transcription polymerase chain reaction (PCR) and rapid amplification of cDNA ends were performed to obtain the P. crocea MT complete cDNA sequence from the total RNA of the testes for the first time. MT was detected in the liver, kidneys, testes, spleen, gill and muscle of P. crocea by tissue-specific expression analysis. Meanwhile, immunohistochemistry staining indicated that the MT protein was localized in germ cells, Sertoli cells and the peripheral connective tissues in P. crocea testes. Furthermore, acute toxicity tests were conducted with cadmium (Cd) to determine the 96 h-medial lethal concentration value. The toxic effects of Cd on the microstructure and ultrastructure of the testes were observed. In addition, the changes in MT mRNA expression levels in the testes after Cd exposure were measured using real-time quantitative PCR. Consequently, we suggest that MTs play an important role in spermatogenesis and testes protection against Cd toxicity in P. crocea.

γ irradiation with different dose rates induces different DNA damage responses in Petunia x hybrida cells

In plants, there is evidence that different dose rate exposures to gamma (γ) rays can cause different biological effects. The dynamics of DNA damage accumulation and molecular mechanisms that regulate recovery from radiation injury as a function of dose rate are poorly explored. To highlight dose-rate dependent differences in DNA damage, single cell gel electrophoresis was carried out on regenerating Petunia x hybrida leaf discs exposed to LDR (total dose 50 Gy, delivered at 0.33 Gy min(-1)) and HDR (total doses 50 and 100 Gy, delivered at 5.15 Gy min(-1)) γ-ray in the 0-24h time period after treatments. Significant fluctuations of double strand breaks and different repair capacities were observed between treatments in the 0-4h time period following irradiation. Dose-rate-dependent changes in the expression of the PhMT2 and PhAPX genes encoding a type 2 metallothionein and the cytosolic isoform of ascorbate peroxidase, respectively, were detected by Quantitative RealTime-Polymerase Chain Reaction. The PhMT2 and PhAPX genes were significantly up-regulated (3.0- and 0.7-fold) in response to HDR. The results are discussed in light of the potential practical applications of LDR-based treatments in mutation breeding.

Effect of gamma irradiation on metallothionein protein expression in Plantago ovata Forsk

PURPOSE

The effect of gamma rays on metallothionein (MT) expression was studied using the medicinal plant Plantago ovata as the test system.

MATERIALS AND METHODS

Western blotting and Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used for this purpose.

RESULTS

Western blot analysis showed significant induction of metallothionein protein following gamma exposure and that induction was highest at 20 Gy gamma dose. At higher gamma doses (100 Gy) MT expression level declined due to degeneration of cells. MALDI-TOF MS analysis indicated the presence of low molecular weight (7-8 kD) MT molecules following the lower radiation doses.

CONCLUSION

It was concluded from the MALDI-TOF MS result that low gamma exposure leads to expression of MT-like protein. At high doses of gamma ray, MT homologues or MT-like protein were not identified, possibly because they might have precipitated due to uncontrolled cross-linking and non-specific aggregation.

Analysis of trace elements during different developmental stages of somatic embryogenesis in Plantago ovata Forssk using energy dispersive X-ray fluorescence

Energy dispersive X-ray fluorescence (ED-XRF) technique has been used for the determination of trace element profile during different developmental stages of somatic embryogenic callus of an economically important medicinal plant, Plantago ovata Forssk. Somatic embryogenesis is a plant tissue culture-based technique, which is used for plant regeneration and crop improvement. In the present investigation, elemental content was analysed using ED-XRF technique during different developmental stages and also determine the effect of additives--casein hydrolysate and coconut water on the trace elemental profile of embryogenic callus tissue of P. ovata. Subsequent experiments showed significant alteration in the concentration of K, Ca, Mn, Fe, Zn, Cu, Br, and Sr in both the embryogenic and non-embryogenic callus. Higher K, Ca, Fe, Cu, and Zn accumulation was in embryogenic tissue stage compared to other stages, suggesting these elements are crucial for successful embryogenesis. The results suggest that this information could be useful for formulating a media for in vitro embryo induction of P. ovata.

PIXE analysis of trace elements in relation to chlorophyll concentration in Plantago ovata Forsk

Plantago ovata Forsk - an economically important medicinal plant - was analyzed for trace elements and chlorophyll in a study of the effects of gamma radiation on physiological responses of the seedlings. Proton-induced X-ray emission (PIXE) technique was used to quantify trace elements in unirradiated and gamma-irradiated plants at the seedling stage. The experiments revealed radiation-induced changes in the trace element and chlorophyll concentrations.