TiO₂ and ZnO Nanoparticles Toxicity in Barley (Hordeum vulgare L.)

Abstract

In this study, the effects of TiO2 and ZnO nanoparticles (0, 5, 10, 20, 40, and 80 mg kg−1) on seed germination, root elongation, chlorophyll content, and the activities of antioxidant enzymes of barley (Hordeum vulgare L.) are studied. The number of seeds germinated and roots elongated in germinated plants (tillering stage) are determined on day 7. Seedlings are transferred to pots containing 50 g turf and grown for 21 days. Antioxidant levels (superoxide dismutase, catalase, ascorbate peroxidase, glutathione, and proline) are determined on day 21 after planting. The results shows that seed germination and root elongation are not significantly affected by types and concentrations of ZnO and TiO2 nanoparticles. However, the antioxidant enzyme activities are diversely affected. Furthermore, the results also show that the ZnO nanoparticles are more toxic to barley plants than the TiO2 nanoparticles.

Higher toxicity of nano-scale TiO2 and dose-dependent genotoxicity of nano-scale SiO2 on the cytology and seedling development of broad bean Vicia faba

“…The former (shortened shoot by n-TiO 2 ) is similar to that observed in Mentha piperita [46]. On the contrary, n-TiO 2 had no effect at lower concentrations of 5-20 mg/L on T. aestivum [14] or even at higher concentrations of 200-4000 mg/L on Z. mays [6].…”

Effects of ZnO Nanoparticles and Ethylenediamine‐N,N′‐Disuccinic Acid on Seed Germination of Four Different Plants

“…In this study, at the concentration of 10 mg L −1 ZnO nanoparticles concentration had an inhibitory effect on bread wheat ( Triticum aestivum L. İkizce) and provocative effect on barley ( Hordeum vulgare L. Ramata). These contradictory effects on rape, ryegrass, Zea mays, maize, and wheat and barley were reported in the literature, before.…”

“…By the way, it has been reported by many researchers that the ZnO nanoparticles variously effected on seed germination, seedling vigor, root elongation on wheat. These studies indicated the positive, negative, or ineffective impacts of ZnO nanoparticles depending on nanoparticles size and concentrations . While Awasthi et al and Solanki and Laura reported the positive effects of ZnO on wheat at about 13 nm (50 mg L −1 ZnO) and 40–50 nm (250 and 500 mg L −1 ZnO) mean size, respectively, on the other hand, Bagawade and Jagtap noted that ZnO nanoparticles (3–5 nm mean size) negatively affected wheat at the concentration of 1000–2000 mg L −1 ZnO.…”

“…The authors concluded that six different test chemicals on lettuce root elongation are effective for the chemicals tested . After Ratsch and Johndro's study, some researchers started to investigate phytotoxic effects of different chemicals (organic or inorganic) using seed germination rate and root–shoot elongation of plants and the others investigated effects of different nanoparticles in the environment …”

Effects of artificial diets and floral nectar on parasitization performance of Trichogramma brassicae Bezdenko, 1968 (Hymenoptera: Trichogrammatidae)

“…When worker bees make a new queen, they choose small larvae and feed them with royal jelly. This type of feeding triggers the development of queen morphology including the fully developed ovaries needed to lay eggs (Doğaroğlu & Doğaroğlu, 2015).…”