Adventitious root system reduces lead uptake and oxidative stress in sunflower seedlings

In this work, the effect of lead on sunflower seedlings with two root system types: primary - formed from embryonic tissues and adventitious - originating from hypocotyl after cutting off primary roots was investigated. The seedlings were subjected to Pb(NO3)(2) in doses: 0, 0.5, 2.5, 5 and 20 mg(Pb) dm(-3) for a week. Lead accumulation, seedling length and mass as well as selected parameters representative of oxidative damage (malondialdehyde) and protection (superoxide dismutase and glutathione) were used to compare stress response of plants. The comparison showed significant differences between plants with different root systems in almost all the parameters and the plants with adventitious root were more tolerant to lead.