Biochemical Changes Observed in Isolated Roots of Phragmites australis Treated with Industrial Wastewater

Abstract: The objective of this study is to highlight the behavior of isolated roots of a plant known for this potential bio-purification (sewage plant): Phragmites australis treated with wastewater discharges from the steel complex of El Hadjar (Annaba). The analysis of the dust released from the complex shows that the majority of the rejected elements are heavy metals with very high concentrations. The evolution of the total protein levels of isolated roots shows that they are much higher than in the roots treated especially during the month of June. Concerning, the content of Proline it varies between 4 and 20 mg/g in roots PF witnesses. In the presence of wastewater rates are 6 times higher; indicating that treatment with wastewater strongly stimulates the synthesis of proline (indicator parameter of stress). Monitoring of the peroxidase enzyme activity (enzyme oxidative stress) shows that the values obtained in isolated roots of Phragmites australis controls tend to decrease as a function of time (less than 50%). Parallel in the presence of water, these values increase to reach a max level. This increase is by 20 % during the month of March, 40 % and 60 % for the months of June and October. Finally, Polarographic monitoring of the respiration of isolated roots showed a high consumption of oxygen at the roots witnesses (nearly 90%). The respiratory activity is strongly reduced in the presence of sewage; the reduction is 50 % /10 minutes. Phragmites australis is a plant that adapts well to oxidative stress generated by wastewater from industrial sources resulted in high levels of proline. This stress causes the activation of detoxification involving the use of anti-oxidant enzyme activities, confirmed by stimulating the synthesis of total protein and by inhibition of respiratory metabolism of the plant