Effects of permissible maximum-contamination levels of VOC mixture in water on total DNA, antioxidant gene expression, and sequences of ribosomal DNA of Drosophila melanogaster

Acaricidal and pathogenic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl tick, Argas persicus (Argasidae)

This study examined the acaricidal, histopathological and genotoxic effects of the entomopathogenic fungus Beauveria bassiana on engorged females of the fowl tick, Argas persicus. The acaricidal effect of B. bassiana (at 10⁶-10¹⁰ conidia/mL) was concentration- and time-dependent. At 10⁶ conidia/mL, the accumulated mortality of treated females ranged from 3.33 ± 3.3 to 13.33 ± 3.3% over 21 days. However, the mortality was remarkably increased after the application of 10¹⁰ conidia/mL, ranging from 6.67 ± 3.3 to 80 ± 5.8%. Females treated with various conidial concentrations exhibited complete inhibition of oviposition. Light and electron microscopic examination of the ovary of engorged female ticks at 3, 6 and 9 days after treatment with 10⁷ conidia/mL revealed that the oocytes exhibited drastic changes that affected their growth and development. The overall damage observed in the ovary included loss of grape-like appearance, distortion of oocytes, cytoplasmic vacuolation, degeneration of organelles and myelin figure formation. Previtellogenic oocyte progression was completely inhibited as the vitellogenic phase was not observed. Random amplified polymorphic DNA (RAPD-PCR) and inter simple sequence repeat (ISSR) methods were used to assess the genotoxic effects of B. bassiana at 10⁷ conidia/mL on engorged female A. persicus over 3 weeks. The lowest percentage of genomic template stability was recorded in paralyzed ticks after 3 weeks. The study demonstrated the efficacy of B. bassiana as a biocontrol agent against A. persicus as it interfered with its reproduction, movement and viability and disrupted its normal tissue and DNA integrity.

The genotoxic effects of mixture of aluminum, arsenic, cadmium, cobalt, and chromium on the gill tissue of adult zebrafish (Danio rerio, Hamilton 1822)

The aim of this study is to investigate the genotoxic effects of mixtures of five metals on zebrafish at two different concentrations; at the permissible maximum contamination levels in drinking water and irrigation waters. The drinking water limits are as follows: 300 µg/L for Aluminum (Al⁺³), 10 µg/L for Arsenic (As⁺³), 5 µg/L for Cadmium (Cd⁺²), 10 µg/L for Cobalt (Co⁺²), and 50 µg/L for Chromium (Cr⁺²). The irrigation water limits: 5000 µg/L for Al⁺³, 100 µg/L for As⁺³, 10 µg/L for Cd⁺², 50 µg/L for Co⁺², and 100 µg/L for Cr⁺². The zebrafish underwent chronic exposure for periods of 5, 10, and 20 days. The gene expressions for mitochondrial superoxide dismutase (SOD2), stress-specific receptor protein NCCRP1, the heat shock proteins: Hsp9, Hsp14, Hsp60, Hsp70, DNA repair (XRCC1 and EXO1), and apoptosis (BOK and BAX) were evaluated. It was found that exposure to the low- and high-concentrations of the heavy metal mixtures caused cell stress, an increased expression of the antioxidant genes, and repair proteins. As the duration of exposure was increased, the cells progressed through the apoptotic pathway. This was more evident in the high-concentration exposure groups. The results demonstrated the necessity for a reevaluation of the maximum values of heavy metal and toxic element concentrations as prescribed by the Local Standing Rules of Water Pollution Control Regulation, as well as a reevaluation of the limitations of heavy metal mixture interactions with respect to ecological balance and environmental health.HighlightsThe purpose of this study was to investigate the genotoxic effects of a mixture of Aluminum, Arsenic, Cadmium, Cobalt, Chromium on zebrafish, within drinking water, and irrigation water limits determining the concentration.The zebrafish were exposed to two different concentrations of each metal mixture for 5-, 10-, and 20-day periods. Following exposure, gene expressions of the zebrafish's gill tissues were examined.As a result of the exposure to the metal mixtures, the following occurred: cell stress, increased antioxidant gene activity, and attempts to protect cell viability. However, the cells progressed through the apoptotic pathway after prolonged exposure.The results demonstrated the necessity for a reevaluation of the maximum limits of metal and toxic element concentrations as stated in the Standing Rules of Water Pollution Control Regulation.

Nonoccupational Exposure of Agricultural Area Residents to Pesticides: Pesticide Accumulation and Evaluation of Genotoxicity

Although many studies related the toxic effects of pesticides on agricultural workers, little research has been done about agricultural area residents. The purpose of this work was to monitor the presence of pesticides, as well as their genotoxic and cytotoxic potential, in humans with blood samples collected from control and intensive agricultural areas in the Thrace region. Pesticide accumulations were determined by LC-MS/MS. Cytotoxicity and genotoxicity were analyzed by comet assay, and the effect of pesticide accumulation on oxidative stress, DNA repair, and molecular chaperone response were analyzed by qRT-PCR assays in the human blood samples. The agricultural area residents had a significantly higher concentration of pesticides than those in the control area at all three sampling times, and the total pesticide amounts were 4.3 and 10 times significantly higher in blood sampled in the pesticide use period (August 2015 and 2016, respectively) than in the nonuse period (November 2015). The results showed that the pesticide level in blood during the use period led to oxidative stress, DNA damage (mean comet length and % tail DNA), and unfolded/misfolded protein response. Particularly, in pesticide use season, difference between these parameters was found statistically significant with comparison to control. Our results indicate that individuals residing around a monoculture rice farming area comprise an at-risk group as a result of increased genotoxicity evidenced in human blood. We suggest that biological monitoring efforts should be used to control nonoccupational exposures to pesticides and thus safeguard the health of agricultural area residents.

Genotoxic effects of olive oil wastewater on sunflower

The aim of this study is to determine in detail the genotoxic effects of Olive Oil Wastewater (OOWW) on sunflower. For this reason, different concentrations of OOWW (1/1,1/10,1/100) were applied as irrigation water to sunflowers at different times (3-day, 5-day, 10-day). In the plants taken during these times, RAPD-based genomic template stability (GTS) assays and gene expression (transcriptomic) levels of different free radical scavenging enzyme genes (SOD, CAT, SOD2, GST, GPX, APX), protein repair/chaperoning genes (HSP26, HSP70, HSP83), N metabolism gene (GS) and apoptotic genes (BAX, BCL2, BCLXL, CYT-C, XIAP) were compared to the those of the control (OOWW-free) group. As a result; The GTS rates seemed to be fairly lower than the control and therefore the OOWW was likely to cause significant damage to the DNA's nucleotide and genomic structure, and the GTS value increased inversely proportional when the OOWW concentration was reduced from 1/1 to 1/10, and after a 10-day application, it seemed to be partly healing. In transcriptomic analysis; all OOWW experiments caused a free radical threat, and especially in 5-day OOWW applications, this raised significantly almost all expressions of antioxidants, protein repair, N metabolism, and apoptotic genes. So, the damages of 5-day OOWW treatments were found to be relatively more than those of 3-day treatments. Regarding 10-day transcriptomic data; a partial repair was found. Additionally, it was determined that the values of B, F, Al, Mn, Ni, Cr, As, Se, Cd, Pb and total polyphenols were high in OOWW. Our findings were also supported by plant images and various heavy metals' and OOWW polyphenols' toxicity results. Our results pointed to key findings in OOWW genotoxicology.

Fusarium infection causes genotoxic disorders and antioxidant-based damages in Orobanche spp

This study aims to evaluate the toxic effects of Fusarium oxysporum on root parasitic weed, Orobanche spp. Comparative genetic and gene expression studies were conducted on uninfected and fungus-infected orobanches. In genetic studies, isolated total DNA was amplified by RAPD PCR. Fragment properties were analysed by GTS test. According to the results, the fragment properties of control and Fusarium infected (experimental) groups varied widely; and it has been observed that Fusarium has genotoxic effects on the DNA of orobanches. In gene expression studies, the expression levels of genes encoding enzymes or proteins were associated with ROS damage and toxic effects, therefore, gene expressions of Mn-superoxide dismutase (SOD), Zn-superoxide dismutase (=SOD2, mitochondrial), glutamine synthetase (GS), heat shock protein gene (HSP70), BAX, Caspase-3 and BCL2 were significantly higher in the experimental group. In the light of obtained data, it was concluded that F. oxysporum (1) caused heavy ROS damage in Orobanche (2) induced significant irrevocable genotoxic effects on the DNA of Orobanche, (3) degraded protein metabolism and synthesis, and finally (4) triggered apoptosis. The results of this study can be a ground for further research on reducing the toxic effects of Fusarium on agricultural products, so that advancements in bio-herbicide technology may provide a sustainable agricultural production.