Effect of Crude Oil on Growth, Oxidative Stress and Response of Antioxidative System of Two Rye (Secale cereale L.) Varieties

Effect of oil contaminants on antioxidant responses and antioxidant properties of Pleurotus florida (P. Kumm)

This research investigated the antioxidant responses of Pleurotus florida at different concentrations of gas oil [0% (control), 2.5%, 5%, and 10% (v:v)] for 30 days. The activities of superoxide dismutase and catalase enzymes decreased in responses to the gas oil presence by an average of 83% and 49%, respectively. In contrast, the activities of the ascorbate peroxidase and glutathione peroxidase enzymes displayed an upward trend in the groups cultured in oil-contaminated media. The gas oil contaminant increased total phenol and flavonoid accumulation, reflecting the variation in secondary metabolism. According to the 1,2-diphenyl-2-picrylhydrazyl radical scavenging, the 2.5% gas oil treatment resulted in the highest antioxidant activity (48 μg mL-1). The highest scavenging activity of nitric oxide radicals (IC50 = 272 μg mL-1) was observed in the treatment with the highest gas oil concentration (10%). Also, this treatment showed an excellent ability to chelate Fe+2 ions (IC50 = 205 μg mL-1). The IC50 values of methanolic extract for nitric oxide scavenging activity and metal chelating ability were significantly reduced by increasing gas oil concentration in the treatments. With increasing the gas oil concentration, malondialdehyde content as a criterion measure of lipid peroxidation level showed significant reduction. These results show that P. florida is resistant to and a compatible mushroom with oil pollutants. Also, the activity of glutathione peroxidase and the ascorbate-glutathione cycle detoxify nitric oxide radicals and products of reactive oxygen species-induced lipid peroxidation in the gas oil treatments.

Advanced bioremediation by an amalgamation of nanotechnology and modern artificial intelligence for efficient restoration of crude petroleum oil-contaminated sites: a prospective study

Crude petroleum oil spillage is becoming a global concern for environmental pollution and poses a severe threat to flora and fauna. Bioremediation is considered a clean, eco-friendly, and cost-effective process to achieve success among the several technologies adopted to mitigate fossil fuel pollution. However, due to the hydrophobic and recalcitrant nature of the oily components, they are not readily bioavailable to the biological components for the remediation process. In the last decade, nanoparticle-based restoration of oil-contaminated, owing to several attractive properties, has gained significant momentum. Thus, intertwining nano- and bioremediation can lead to a suitable technology termed 'nanobioremediation' expected to nullify bioremediation's drawbacks. Furthermore, artificial intelligence (AI), an advanced and sophisticated technique that utilizes digital brains or software to perform different tasks, may radically transfer the bioremediation process to develop an efficient, faster, robust, and more accurate method for rehabilitating oil-contaminated systems. The present review outlines the critical issues associated with the conventional bioremediation process. It analyses the significance of the nanobioremediation process in combination with AI to overcome such drawbacks of a traditional approach for efficiently remedying crude petroleum oil-contaminated sites.

Assessment of the toxicity of weathered petroleum hydrocarbon impacted soils to native plants from a site in the Canadian Subarctic

Remedial guidelines for petroleum hydrocarbons (PHCs) in soil aid in the mitigation of risks to human health and the environmental. However, some remediation guidelines may overestimate the potential for adverse effects to native plant species, contributing to unnecessary remedial efforts in attempts to meet the guidelines. At sites where PHC-contaminated soils undergo weathering, some PHCs may persist but with decreased bioavailability to organisms. In this study, the toxicity of both coarse and fine-grained subarctic soils, contaminated with weathered PHCs were assessed using five native plant species (Picea mariana, Achillea millefolium, Alnus viridis, Elymus trachycaulus and Salix bebbiana). Soil toxicity tests were conducted in a growth chamber with parameters set to simulate the site's subarctic climate conditions. Reference toxicant tests using boric acid were conducted to provide confidence in the interpretation of the results for the PHC-contaminated soils, and also provide new information on the sensitivities of the four boreal species to boric acid. All plants exhibited reduced growth and germination rates as boric acid concentrations increased. Despite exceeding the Canada-wide standard guidelines for Fraction 3 PHCs, field-collected contaminated soils had no significant negative impacts on the growth (i.e., length, dry weight and emergence) of any of the plant species tested.

Eco-physiological response and genotoxicity induced by crude petroleum oil in the potential phytoremediator Vinca rosea L

Background

Phytoremediation is determined as an emerging green technology suitable for the safe remediation and restoration of polluted terrestrial and aquatic environments. In this study, the assessment of an ornamental plant, Vinca rosea L., as a phytoremediator of crude oil in polluted soils was conducted. In an open greenhouse experiment, plants were raised in sandy-clayey soils treated with 1, 3, 5, and 7% oil by weight. The experiment was conducted over 5 months.

Results

Total petroleum hydrocarbon (TPH) degradation percentage by V. rosea after a 5-month growth period ranged from 86.83 ± 0.44% to 59.05% ± 0.45% in soil treated with 1 and 7%, respectively. Plants raised in polluted soils demonstrated a dramatic reduction in germination rates, in addition to growth inhibition outcomes shown from decreased plant height. An increase in branching was observed with an increase in oil pollution percentages. Moreover, the phytomass allocated to the leaves was higher, while the phytomass witnessed lower values for fine roots, flowering and fruiting when compared to the controls. Apart from the apparent morphological changes, there was a decrease in chlorophyll a/b ratio, which was inversely proportional to the oil pollution level. The contents of carotenoids, tannins, phenolics, flavonoids, and antioxidant capacity were elevated directly with an increase in oil pollution level. The start codon-targeted (SCoT) polymorphisms and inter-simple sequence repeat (ISSR) primers showed the molecular variations between the control and plants raised in polluted soils. The genetic similarity and genomic DNA stability were negatively affected by increased levels of crude oil pollution.

Conclusions

The ability of V. rosea to degrade TPH and balance the increased or decreased plant functional traits at the macro and micro levels of plant structure in response to crude oil pollution supports the use of the species for phytoremediation of crude oil-polluted sites. The genotoxic effects of crude oil on V. rosea still require further investigation. Further studies are required to demonstrate the mechanism of phenolic, flavonoid, and antioxidant compounds in the protection of plants against crude oil pollution stress. Testing different molecular markers and studying the differentially expressed genes will help understand the behavior of genetic polymorphism and stress-resistant genes in response to crude oil pollution.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43141-022-00412-6.

Role of Different Material Amendments in Shaping the Content of Heavy Metals in Maize (Zea mays L.) on Soil Polluted with Petrol

Petroleum substances are among the xenobiotics that most often contaminate the natural environment. They have a strong effect on soil, water, and other components of the environment. The aim of this pot experiment has been to determine the effect of different soil material amendments (compost, 3%; bentonite, 2% relative to the soil mass or calcium oxide, in amounts corresponding to one full hydrolytic acidity) on the content of heavy metals in aerial parts of maize (Zea mays L.) grown on soil polluted with petrol (0, 2.5, 5, and 10 cm3 kg−1 of soil). The content of all heavy metals, except copper, in the aerial biomass of maize was positively correlated, but biomass yield negatively correlated, with the increasing doses of petrol. The highest increase in the content of heavy metals was noted for chromium and manganese. Materials used for phytostabilisation (compost, bentonite, and calcium oxide) had a significant effect on the content of heavy metals and biomass yield of maize. They contributed to the modified accumulation of elements, especially chromium, copper, and cobalt in the aerial biomass of maize. In comparison with the control series (without material amendments), the application of calcium oxide proved to be most effective. It had the most evident influence on the chemical composition of maize, limiting the accumulation of lead, zinc, manganese, and iron and increasing biomass yield.

Fungicide-loaded mesoporous silica nanoparticles promote rice seedling growth by regulating amino acid metabolic pathways

Mesoporous silica nanoparticles (MSN) are widely researched as carriers for pesticides (including fungicides, insecticides and herbicides) to improve their effective utilization rate in the target plant. However, pesticides enter the target crops and may bring some impacts on the growth and physiological function of plants. When they are loaded to nanoparticles, different effects on the metabolic properties of target plants will be produced. In this study, thifluzamide-loaded MSN was prepared with average diameter of 80-120 nm. Rice seedlings were exposed for 7 days to different treatments of MSN, thifluzamide, and thifluzamide-loaded MSN. After treatment, non-targeted metabolomic method was employed to explore the metabolic pathways. It was found that the negative effect of thifluzamide to rice seedling was alleviated by thifluzamide-loaded MSN, since it increased amino acid metabolic pathways, which improved purine and pyrimidine metabolism and induced the production of total protein. Thifluzamide-loaded MSN can also relieve the damage of thifluzamide to rice seedlings by altering the chlorophyll, phenols and flavonoids content. In conclusion, it was proposed that the mechanism of fungicide-loaded MSN prevent plant from negative effects of fungicides by regulating the amino acid metabolic pathways.

Transcriptome analysis revealed key genes involved in flavonoid metabolism in response to jasmonic acid in pigeon pea (Cajanus cajan (L.) Millsp.)

Flavonoids are important metabolites of pigeon pea in relation to its stress resistance. However, the molecular basis and regulatory mechanisms of flavonoids in pigeon pea remain unclear. Methyl jasmonate (MeJA) is a signaling molecule associated with biosynthesis of flavonoids. In this study, after exogenous treatment of 10 mg/L MeJA, infection of pathogenic fungi to pigeon pea was alleviated and the content of flavonoids was increased. Results of gene expression and metabolic changes that were respectively analyzed by transcriptome sequencing and high performance liquid chromatography (HPLC) showed that (1) concentrations of various flavonoids, such as genistein, apigenin, vitexin and biochanin A were significantly up-regulated; (2) 13675 differentially expressed genes were produced, mainly enriched in signal transduction and isoflavone biosynthesis pathways: (3) the expression levels of key synthase genes (CcI2'H, CcHIDH, Cc7-IOMT) in the flavonoid biosynthesis pathway were significantly up-regulated; (4) Overexpression of CcbHLH35 significantly induced upregulation of flavonoid synthase genes and accumulation of genistein, vitexin and apigenin. Our findings reveals the pivotal roles of MeJA in synthesis and functioning of flavonoids in pigeon pea, which provide a basis for further studies on flavonoid-mediated defense responses.

Influence of Hydrocarbon-Oxidizing Bacteria on the Growth, Biochemical Characteristics, and Hormonal Status of Barley Plants and the Content of Petroleum Hydrocarbons in the Soil

Much attention is paid to the relationship between bacteria and plants in the process of the bioremediation of oil-contaminated soils, but the effect of petroleum degrading bacteria that synthesize phytohormones on the content and distribution of these compounds in plants is poorly studied. The goal of the present field experiment was to study the effects of hydrocarbon-oxidizing bacteria that produce auxins on the growth, biochemical characteristics, and hormonal status of barley plants in the presence of oil, as well as assessing the effect of bacteria and plants separately and in association with the content of oil hydrocarbons in the soil. The treatment of plants with strains of Enterobacter sp. UOM 3 and Pseudomonas hunanensis IB C7 led to an increase in the length and mass of roots and shoots and the leaf surface index, and an improvement in some parameters of the elements of the crop structure, which were suppressed by the pollutant. The most noticeable effect of bacteria on the plant hormonal system was a decrease in the accumulation of abscisic acid. The data obtained indicate that the introduction of microorganisms weakened the negative effects on plants under abiotic stress caused by the presence of oil. Plant-bacteria associations were more effective in reducing the content of hydrocarbons in the soil and increasing its microbiological activity than when either organism was used individually.

Potentiality of Azolla pinnata R. Br. for Phytoremediation of Polluted Freshwater with Crude Petroleum Oil

The pollution of freshwater resources with crude petroleum oil is a major environmental issue in oil-producing countries. As a result, the remediation of polluted aquatic ecosystems using eco-friendly and cost-effective technology is receiving increased global attention. In this study, the ability of Azolla pinnata R. Br. to remediate petroleum-polluted freshwater was assessed. The remediation potentiality was determined by evaluating the total petroleum hydrocarbon degradation percentage (TPH%) and changes in the molecular type composition of saturated and aromatic hydrocarbon fractions. TPH% was estimated gravimetrically, and changes in the molecular type composition of saturated and aromatic fractions were measured using gas chromatography and high-performance liquid chromatography, respectively. The results reveal that A. pinnata has the potential to phytoremediate freshwater polluted with low levels (up to 0.5 g/L) of petroleum hydrocarbons (PHs). After seven days of phytoremediation, the degradation rate of total PHs was 92% in the planted treatment compared with 38% in the unplanted positive control. The highest breakdown of PHs for the normal paraffinic saturated hydrocarbon fraction occurred in the presence of A. pinnata combined with Anabena azollaea (A-A), which showed a moderate degradation capacity toward total aromatic hydrocarbons (TAHs) and total polycyclic aromatic hydrocarbons (PAHs). The results indicate that A. pinnata effectively removed C18, a saturated PH, and acenaphthene (Ace), an aromatic PH. Therefore, this study suggests that A. pinnata is a useful tool for the remediation of freshwaters contaminated with low pollution levels of crude oil.