Chlorophyll Content in Two Medicinal Plant Species Following Nano-TiO₂ Exposure

Chlorophyll content in leaves is a convenient indicator of the physiological state of the plant following exposure to a stressor. In the present study, a pot experiment was carried out using two medicinal plant species - peppermint (Mentha X piperita L.) and common sage (Salvia officinalis L.) to determine the link between the chlorophyll content in the plant leaves and the exposure of the plants to nano-TiO₂ either through the leaves (in suspension) or through the root system (in soil). Following the exposure, the shoots were analysed for the contents of Ti, Al, Ca, K, Mg, Mn, Na and chlorophyll. Significant decrease in chlorophyll content was observed in all but one of the nano-TiO₂ treatments, the differences in the determined element content were mostly species-dependent: Ti exposure was found to be related to the decrease in the chlorophyll and Mn content in both species as well as to the decrease in Mg content in common sage.