Detection of heavy metal contamination in Batlama Stream (Turkiye) and the potential toxicity profile

Comparative investigation on chemical and green synthesized titanium dioxide nanoparticles against chromium (VI) stress eliciting differential physiological, biochemical, and cellular attributes in Helianthus annuus L

Nanotechnology is a new scientific area that promotes unique concepts to comprehend the optimal mechanics of nanoparticles (NPs) in plants under heavy metal stress. The present investigation focuses on effects of synthetic and green synthesized titanium dioxide nanoparticles (TiO2 NPs and gTiO2 NPs) against Cr(VI). Green TiO2 NPs have been produced from plant leaf extract (Ricinus communis L.). Synthesis was confirmed employing an array of optical spectroscopic and electron microscopic techniques. Chromium strongly accelerated H2O2 and MDA productions by 227 % and 266 % at highest chromium concentration (60 mg/kg of soil), respectively, and also caused DNA damage, and decline in photosynthesis. Additionally, anomalies were observed in stomatal cells with gradual increment in chromium concentrations. Conversely, foliar applications of TiO2 NPs and gTiO2 NPs considerably mitigated chromium stress. Sunflower plants treated with modest amounts of green TiO2 NPs had significantly better growth index compared to chemically synthesized ones. Principal component analysis highlighted the variations among photosynthetic attributes, oxidative stress markers, and antioxidant defense systems. Notably, gTiO2 supplementation to the Cr(VI) strained plants minimized PC3 production which is a rare report so far. Conclusively, gTiO2 NPs have been identified to be promising nano-based nutrition resource for farming applications.

Effect of Melissa officinalis L. leaf extract on manganese-induced cyto-genotoxicity on Allium cepa L

Although the antioxidant properties of Melissa officinalis extract (Mox) are widely known, little work has focused on its protective capacity against heavy metal stress. The primary objective of this study was to determine the potential of Mox to mitigate manganese (II) chloride (MnCI2)-induced cyto-genotoxicity using the Allium and comet assays. Physiological, genotoxic, biochemical and anatomical parameters as well as the phenolic composition of Mox were examined in Allium cepa (L.). Application of 1000 µM MnCl2 reduced the rooting percentage, root elongation, weight gain, mitotic index and levels of chlorophyll a and chlorophyll b pigments compared to the control group. However, it increased micronuclei formation, chromosomal abnormality frequencies, tail DNA percentage, proline amount, lipid peroxidation level and meristematic damage severity. The activities of superoxide dismutase and catalase also increased. Chromosomal aberrations induced by MnCl2 were fragment, sticky chromosome, vagrant chromosome, unequal distribution of chromatin and bridge. Application of 250 mg/L Mox and 500 mg/L Mox along with MnCl2 significantly alleviated adverse effects dose dependently. The antioxidant activity bestowed by the phenolic compounds in Mox assisted the organism to combat MnCl2 toxicity. Consequently, Mox exerted remarkable protection against MnCl2 toxicity and it needs to be investigated further as a potential therapeutic option.