Influence of platinum ions on phenolic compounds in Lepidium sativum seedlings

Despite limiting the transport emitted pollution, contamination of the roadside environment remains an important issue. Due to necessity to decrease the lead emission, catalytic converters modifications were introduced. It caused increase of Platinum Group Elements (PGEs) emission, which was rare in the environment before. So far there is lack of information about platinum contamination to functioning of plants which are so important in the urban environment. In the experiment garden cress (Lepidium sativum) were sown into Petri dishes filled with filter paper soaked with solutions of different platinum concentration. There were used two compounds containing platinum at different oxidation states PtCl4 - ssolutions containing 0.58, 2.89, 5.79, 11.58 and 23.16 mg Pt4+•dm−3 and [Pt(NH3)4] (NO3)2 - solutions containing 0.50, 2.52, 5.04, 10.08 and 20.15 mg Pt2+•dm−3 in every combination of the experiment. In every combination there were five Petri dishes, experiment was repeated twice. To estimate plant response to stress factor, phenolic compounds contents were analyzed in the roots and shoots parts separately. The highest amount of total phenolics in roots was recorded in plants treated with highest Pt4+ dose which was 23.16 mg•dm−3, seeds treated with other doses of platinum (including those treated with highest dose of Pt2+ did not differ significantly from control plants. In the case of phenolic compounds in the aboveground parts of seedlings there was highest accumulation than in roots. Highest amounts of phenolics were recorded in plants also treated with Pt4+ in doses 11.58 and 23.16 mg•dm−3.