Assessment of Eco-Physiological Performance of Quercus ilex L. Leaves in Urban Area by an Integrated Approach

Plant physiological performance may be endangered in contaminated urban areas. Metal and polycyclic aromatic hydrocarbon (PAH) content in Quercus ilex leaves mainly reflects air pollution, being for these pollutants traceable the translocation from soil. In this work, in a field study, the responses at structural and functional level of Q. ilex leaves to metal and PAH pollution were assessed by an integrated approach. At this purpose, morphological (functional traits), biochemical (pigment content, antioxidant capacity, and PARP activity), and physiological (partitioning of absorbed light in the photosynthetic process) analyses were performed in leaves collected at urban parks and roadsides. Compared to the leaves of the urban parks, those sampled at the roadsides showed higher metal and PAH accumulation. The most contaminated leaves showed smaller leaf sizes and lower relative water and pigment content, as well as a lower photochemistry. In this circumstance, the excess of absorbed light at PSII was mainly dissipated via non-regulated than heat processes. On the basis of the biochemical analyses, the occurrence of DNA damages in contaminated Q. ilex leaves may be hypothesized.