The Effects of Zinc Oxide (ZnO) Nanoparticles on the Germination, Biochemical and Ultrastructural Cell Characteristics of Ricinus communis

Aim: The present research attempts to study the effect of different concentrations of zinc oxide (ZnO) nanoparticles on the germination, the amount of photosynthetic pigments and sugar content and analyze the ultrastructure of Ricinus communis plant leaves.
Material and Experiment were performed under controlled greenhouse conditions, and designed completely randomly with three incidents. The plants were exposed to various concentrations (0, 10, 100, 500 and1000) mg/l of zinc oxide nanoparticles. The ultrastructural Characteristics of plant leaves were made with the use of TEM electron microscope in the experimental plants of 1000 mg/l.
Treatment of the plant with (ZnO) Nanoparticels at concentration of 10 mg/l caused increased and higher concentrations significantly reduced the rate and percentage of germination, as well as the radicle and plumule length and the photosynthetic pigments. The amount of soluble sugars in leaves increased significantly with the increase of nanoparticle concentration. The images TEM electron microscope revealed the concentration of zinc oxide nanoparticles and cell membrane rupture, as well as a deformation and decrease of the number of chloroplasts in the1000 mg/l treated plants, compared with the control plants.
The Zn absorption by the plant increases by increasing the concentration of (ZnO) nanoparticles. At high concentrations due to toxicity, germination parameters in the plant decrease, which leads to oxidative stress in the plant. The plant in response to this stress increases its sugar content. In these conditions, the amount of photosynthetic pigments decreased and caused ultrastructural ruptures in plant cells.