Brassica napus Growth in Lead-Polluted Soil: Bioaccumulation in Plant Organs at Different Ontogenetic Stages and Lead Fractionation in Soil

Abstract

Lead is known to be a highly toxic metal; it is often found in soils with the potential to be incorporated by plants. Here, the bioaccumulation of lead by rapeseed (Brassica napus) from a soil with Pb(II) added just before sowing is studied. The effect on plant organs is also studied at the ontogenetic stages of flowering and physiological maturity. Moreover, the chemical fractionation of Pb in the rhizosphere and bulk soil portions is investigated and related to Pb accumulation in plant organs. B. napus are found to accumulate Pb in its organs: 1.5-19.6 mg kg −1 in roots, 3.3-15.6 mg kg −1 in stems, 0.5-8.6 mg kg −1 in leaves in all treatments, and in grains 1.45 mg kg −1 at physiological maturity and only for the highest Pb dose (200 mg kg −1 ). Plant biomass reduction was observed to be about 20% at the flowering stage and only for the highest Pb dose. The analysis of metal fractionation in soil shows Pb migration from the bulk soil to the rhizosphere, attributed to concentration gradients created by root intake. Along the time period studied, lead chemical fractionation in soil evolved toward the most stable fractions, which coupled to plant uptake depleted the soluble/ exchangeable one (assumed bioavailable).

Long-term field study on stabilization of contaminated wastes by growing clonally reproduced Silene vulgaris calamine ecotype

“…Some tolerant plants tend to restrict soil-root and root-shoot transfers, and therefore accumulate low amounts of metals, while hyperaccumulators actively take up and translocate metals into their aboveground organs. Plants with TF and particularly BCF values below one are unsuitable for phytoextraction but may be efficient in phytostabilization schemes (Yoon et al 2006;Ferreyroa et al 2018). Our experiments with S. vulgaris calamine population showed that both Zn and Cd TF coefficients were too low to use this species for effective phytoextraction.…”

Enhancing Phytoextraction Potential of Brassica napus for Contaminated Dredged Sediment Using Nitrogen Fertilizers and Organic Acids

“…Therefore, even the highest concentration measured in Brassica napus shoots was 26 times lower than in the sediment. Other authors also recorded low Pb uptake by Brassica napus [ 59 , 60 , 61 , 62 ].…”

Toxic metals in pregnancy and congenital heart defects. Insights and new perspectives for a technology-driven reduction in food sources

“…Phytoextraction, the most common form of phytoremediation, uses hyper-accumulators able to extract 50-500 times more pollutants than normal plants, and genetic engineering has allowed to transfer hyper-accumulator genes from plants having low biomass to others with high biomass such as Brassica species [161]. Several Brassica species were reported to moderately accumulate quantities Cd, Pb, and As [167][168][169]. Furthermore, the use of chelating agents such as synthetic ethylenediaminetetraacetic acid, increasing the solubility of the metals in soils, improves plant metal uptake and, consequently, soil decontamination [161,164].…”