Are the physiological and biochemical characteristics in dandelion plants growing in an urban area (Pisa, Italy) indicative of soil pollution?

Physiological and biochemical characteristics were evaluated in dandelion plants (Taraxacum officinale) growing naturally in an urban environment. The study area was located in Pisa, Italy, and 27 sites in the municipality were chosen to assess the biochemical and physiological features of dandelion plants and the trace metal content in the urban soil. Concentrations of elements including, Cr, Cu, Mn and Zn were analysed in the soil together with dandelion shoot and root tissues collected from the various sites. Chlorophyll a fluorescence analysis, the pigment content, antioxidant power and phenol content were determined in dandelion. The results showed very limited soil pollution due to trace metals in the urban sites. However, dandelion showed Zn uptake and translocation although no damage was observed in the plants. Our results highlight that dandelion plants are able to survive in a constrained environment thanks to the high phenol content which is effective in combatting the oxidative stress induced by heavy metals.