Mutagenic effects of spent potliner and derivatives on Allium cepa L. and Lactuca sativa L.: A molecular approach

Complementary advantages of spent pot lining and coal gangue in the detoxification and valuable components recovery process

As a hazardous solid waste rich in carbon and fluorine, spent pot lining (SPL) is a huge threat to sustainable production and environmental security. As abundant carbon and fluorine resources, the use of such valuable components has great practical and economic significance. Based on the environmental concerns and the component characteristics of SPL, coal gangue (CG), the largest output of solid wastes in the coal-producing industry and rich in aluminum and silicon, was introduced in the utilization and detoxification process of SPL in this work. The substance flow of the co-utilization process presents a circular economy and complementary advantages of SPL and CG. Pure regular fibrous silicon carbides were obtained owing to the synergy effect of SPL and CG. Aluminum from CG and SPL was utilized to prepare dawsonite combined with the sodium from the impurities removal process. Pure cryolite was obtained via mixing wastewater from the silicon carbide purification process and the dawsonite extraction process. Almost all components in SPL and CG were converted into valuable products, and no wastewater and residue was discharged. Thus, a sustainable process of trash to treasure and circular economy for treating CG and SPL was established here with environmental and economically friendly characteristics, which gave a new insight into utilizing wastes with complementary advantages.

Ultrastructural and molecular implications of ecofriendly made silver nanoparticles treatments in pea (Pisum sativum L.)

Background

Silver nanoparticles (AgNPs) are the most widely used nanomaterial in agricultural and environmental applications. In this study, the impact of AgNPs solutions at 20 mg/L, 40 mg/L, 80 mg/L, and 160 mg/L on cell ultrastructure have been examined in pea (Pisum sativum L) using a transmission electron microscope (TEM). The effect of AgNPs treatments on the α, β esterase (EST), and peroxidase (POX) enzymes expression as well as gain or loss of inter-simple sequence repeats (ISSRs) markers has been described.

Results

Different structural malformations in the cell wall and mitochondria, as well as plasmolysis and vacuolation were recorded in root cells. Damaged chloroplast and mitochondria were frequently observed in leaves and the osmiophilic plastoglobuli were more observed as AgNPs concentration increased. Starch grains increased by the treatment with 20 mg/L AgNPs. The expressions of α, β EST, and POX were slightly changed but considerable polymorphism in ISSR profiles, using 17 different primers, were scored indicating gain or loss of gene loci as a result of AgNPs treatments. This indicates considerable variations in genomic DNA and point mutations that may be induced by AgNPs as a genotoxic nanomaterial.

Conclusion

AgNPs may be used to induce genetic variation at low concentrations. However, considerations should be given to the uncontrolled use of nanoparticles and calls for evaluating their impact on plant growth and potential genotoxicity are justified.

Determination of malathion's toxic effect on Lens culinaris Medik cell cycle

The present study aimed to determine the toxic effect of malathion pesticide on root growth, cell division and the chromosomal abnormalities frequency using the L. culinaris test. Initially, the lentil seeds were subjected to different doses of malathion (0.0 0.5, 1, 2.5, 5, 10, 15, 20, 25 and 30 mgL^-1) and during 24, 48, and 72 h, the root length was measured. Subsequently, at 72h, the mitotic index, mitotic inhibition, and cellular abnormalities were calculated for all treatments. According to the obtained results, it was visualized that the root growth was inversely proportional to the concentration of malathion at all times of exposure. After 72h of exposure, the lowest values of the mitotic index and inhibition were presented at malathion concentrations 20, 25 and 30 mgL^-1. Additionally, micronuclei cell abnormalities, metaphase sticky chromosomes, split chromosomes, nuclear lesions, irregular anaphase, anaphase bridges, binucleated cells, absence of nucleus and telophase bridge were observed. Finally, Malathion induced mitodepressive and cytotoxic effects in the meristematic cells of the L. culinaris root tip. A high frequency of abnormality was found in the micronuclei, which represented an indicator of a high degree of toxicity at the cellular level.

Cytogenotoxic effect of propanil using the Lens culinaris Med and Allium cepa L test

Propanil can produce methemoglobinemia, hemolytic anemia, hepatotoxicity, metabolic disorder and nephrotoxicity. It also has a genotoxic effect, although it is not listed as a carcinogen and it continues to be applied excessively throughout the world. Consequently, in this study the cytogenotoxic effect of propanil was evaluated, using apical root cells of Allium cepa and Lens culinaris. In which, L. culinaris seeds and A. cepa bulbs were subjected to 6 treatments with propanil (2, 4, 6, 8, 10 and 12 mg L^-1) and to distilled water as control treatment. Subsequently, the root growth was measured every 24 h for 3 days. Next, the mitotic index and cellular anomalies were determined. Whereby, decreased root development was observed in all treatments. Likewise, greater inhibition of mitosis was evidenced in L. culinaris compared to A. cepa. In addition, chromosomal abnormalities, such as nucleus absence, sticky chromosomes in metaphase and binucleated cells, were present in most of the treatments. Thus, the presence of micronuclei and the results of L. culinaris, indicate the high cytogenotoxicity of propanil and the feasibility of this species as bioindicator.

Toxicological effects of comercial formulations of fungicides based on procymidone and iprodione in seedlings and root tip cells of Allium cepa

In this study the phytotoxic, cytotoxic, genotoxic and mutagenic effects of two commercial fungicide-active compounds, procymidone (PR) and iprodione (IP), were determined. The parameters evaluated were germination and root growth, mitotic index, chromosomal and nuclear aberrations, and molecular analyses were also performed in the model plant Allium cepa L. The results demonstrated that the active compounds PR and IP were phytotoxic, delaying germination and slowing the development of A. cepa seedlings. Moreover, PR and IP showed cytogenotoxicity towards A. cepa meristematic cells, inducing chromosomal changes and cell death. The mutagenic activity of the active compounds was demonstrated by the detection of DNA changes in simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) markers in the treated cells compared to the negative control. Together, these results contribute to a better understanding of the damage caused by these substances in living organisms and reveal a promising strategy for prospective studies of the toxic effects of environmental pollutants.