Acid mine drainage (AMD) endangers pomegranate trees nearby a copper mine

Acid mine drainage (AMD) is known as an important source of environmental pollution with potentially toxic ele-ments. High concentrations of minerals in soil were observed in a pomegranate garden nearby a copper mine, Chaharmahal and Bakhtiari, Iran. In the vicinity of this mine, AMD locally caused distinct chlorosis in pomegranate trees. As expected, potentially toxic concentrations of Cu, Fe, and Zn were accumulated in the leaves of the chlorotic pomegranate trees (YLP), i.e., increased by 69 %, 67 % and 56 %, respectively, compared to the non-chlorotic trees (GLP). Remarkably, also some other elements, including Al (82 %), Na (39 %), Si (87 %), and Sr (69 %) were consid-erably enhanced in YLP, compared to GLP. On the other hand, the foliar Mn concentration in YLP was strongly de-creased, about 62 % lower than that in GLP. The most plausible reasons for chlorosis in YLP are either toxicity of Al, Cu, Fe, Na, and Zn, or a deficiency of Mn. In addition, AMD led to oxidative stress, shown by a high accumulation of H2O2 in YLP, and a strong upregulation of enzymatic and non-enzymatic antioxidants. AMD apparently caused chlo-rosis, reduced the size of individual leaves, and caused lipid peroxidation. A further analysis of the adverse effect of the responsible AMD component(s) could be helpful to reduce the risk of food chain contamination.

Automated summary

High concentrations of minerals in soil near a copper mine in Iran caused chlorosis and reduced growth in pomegranate trees. The chlorotic trees showed increased levels of toxic elements such as copper, iron, and zinc, while manganese levels were significantly decreased. The chlorosis in the trees may be caused by toxicity of certain elements or a deficiency of manganese. Additionally, acid mine drainage led to oxidative stress and lipid peroxidation in the affected trees.