Influence of platinum ions on phenolic compounds in Lepidium sativum seedlings

Abstract

Despite limiting the transport emitted pollution, contamination of the roadside environment remains an important issue. Due to necessity of decrease the lead emission, catalytic converters modifications were introduced. It caused increase of Platinum Group Elements (PGEs) emission, which were rare in the environment before. It was proved that platinum present in the street dust and urban soils is bioavailable to plants. 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 (0, 1, 5, 10, 20 and 40 mg compound·dm^-3). There were used two compounds containing platinum at different oxidation states Pt⁺⁴ (PtCl₄)and Pt⁺² ([Pt(NH₃)₄](NO₃)₂) in every combination of the experiment. In every combination there was five Petri dishes, experiment was repeated twice. To estimate plant response to stress factor, phenolic compounds content were analyzed in the roots and shoots parts separately.

The highest amount of total phenolics in roots were recorded in plants treated with highest Pt⁺⁴ dose which was 40mg compound·dm^-3, other objects (including those treated with highest dose of Pt⁺²) 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 Pt⁺⁴ in doses 20 and 40 mg compound·dm^-3.