Investigation of phenolic compounds potential to reduce dust pollution of pomegranate trees.

The present study was carried out in two seasons from two areas at different distances from the industrial zone of Gabes city which is classified as a Mediterranean host-spot pollution region. Pomegranate tree were highly exposed to various industrial air pollutants containing Zn and Cu. The relation between Zn, Cu, morphological, physiological and biochemical changes induced in pomegranate leaves was evaluated based to the measurement of leaf heavy metals, leaf changes, total phenolic content and quali-quantification of individual phenol profile by LC-ESI-MS.Results showed that the highest levels of metals were found in the closet site to the industrial area. This accumulation varied significantly between areas and seasons and cause significant increase of necrosis leaf area, decrease of leaf area, green leaf area and specific leaf area. LC-ESI-MS analysis showed a spatial and seasonal variation of total phenolic acids and flavonoids which indicate that phenolic compounds are rigorously depending to stressful conditions. A significant positive correlation was found among total Zn, Cu, necrosis, cirsiliol, caffeic and trans-ferulic acids. This accumulation can serve as protective defensive mechanism to minimize the air pollutants effects, chelate Zn and Cu and then to improve the resistance of pomegranate trees.