Comparison the effect of phenanthrene and Pyrene, on seed germination and growth parameters of seedlings in sunflower plant

Polycyclic Aromatic Hydrocarbons (PAHs), usually as byproducts of carbon-based fuel combustions, are an important group of pollutants with wide distribution in the environment. PAHs are toxic for almost all organisms, and plants can uptake such compounds via roots and translocate to various aerial parts. Given that germination is the first and most important stage of plant growth, the main objective of this research is to evaluate the effects of phenanthrene and pyrene, as well-known PAHs, on germination, root growth, dry and wet weight of seedlings, as well as biochemical activities in sunflower (Helianthus annuus L). For this purpose, the seeds were hydroponically cultivated in a perlite substrate treated with various concentrations of phenanthrene and pyrene (۰, ۵۰ and ۱۰۰ ppm) and then intended investigations were done. The results showed that both contaminants had inhibitory effects on germinations and growth parameters, however pyrene had a greater effect than that of phenanthrene. Hydrogen peroxide contents were increased by phenanthrene and pyrene treatments. Also soluble sugar content was significantly reduced in the roots, while it was increased in the shoots of plants treating by ۵۰ ppm of pyrene compared to the control. Overall, the negative effect on growth as well as some biochemical parameters of the sunflower plant is probably due to the oxidative stress generated by these compounds which was shown with increased hydrogen peroxide. This eventually reduced germination and growth parameters of the sunflower plant.In order to expand this work, the structural and ultrastructural changes in the cells and tissues of sunflower plant under the influence of phenanthrene and pyrene can be studied.

کلیدواژه ها:

Polycyclic Aromatic Hydrocarbons (PAHs) ، Hydrogen peroxide ، Oxidative stress ، sugar content