Toxic effects of phenanthrene on physiological parameters of maize (Zea mays L.)

Polycyclic aromatic hydrocarbons (PAHs) are an important group of pollutants which are released into the environment mainly due to the incomplete combustion of organic materials. These compounds could reduce the growth of plants and affects their different physiological aspects. In this study, Zea mays plants were grown hydroponically and treated by different concentrations of phenanthrene (0, 25, 50, 75 and 100 ppm) and its effects on some physiological and biochemical parameters were evaluated. The results showed that the increase in phenanthrene concentration reduced all studied growth parameters and significantly increased H2O2, Chlorophyll a, and carotenoids contents of plants. Also, an increased trend was observed in anthocyanin s content compared to the control and the highest value (118.44%) was recorded at the level of 100 ppm, but there was no significant difference between plants treated. Therefore, these findings supported the concept that phenanthrene toxicity induced oxidative stress in the plant as was shown by H2O2 accumulation in the plant being physiological reasons for plants growth reduction in phenanthrene contaminated environments