Abstract
The aim of this study is to design de novo prediction models in order to gauge the likely uptake of eight heavy metals (Al, Cr, Cu, Fe, Mn, Ni, Pb and Zn) by Lycopersicon esculentum, the tomato plant. Uptake was assessed within the plant’s root, stem, leaf and fruit tissues, respectively. The plant was cultivated in soil amended by different application rates of sewage sludge, i.e. 0, 10, 20, 30 and 40 g/kg. The roots exhibited markedly elevated heavy metal concentrations compared to the above-ground plant components, with the exception of the quantity of Ni in the leaves. Apart from Al, Fe and Mn, a bioconcentration factor >1 was identified for all heavy metals. Excluding Ni in the leaves, all tested heavy metals exhibited a translocation factor < 1. The regression models were deployed to predict the accretion of the heavy metals under investigation within the various parts of L. esculentum. These were founded on the parameters of the equivalent eight heavy metals within the soil, pH and organic matter content. Student’s unpaired t-tests revealed no differences between the actual and predicted heavy metal concentrations in the roots, stems, leaves or fruits of the tomato plant. These data suggest an excellent model goodness of fit in terms of its accuracy to forecast the degree of heavy metal uptake. The constructed models may therefore facilitate the safe propagation of L. esculentum in growing media amended with sewage sludge, and concurrently provide a risk assessment with respect to human well-being.
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•Most heavy metals (HMs) were more concentrated in the L. esculentum roots than in any other tissue.•Most HM levels in L. esculentum tissues correlate significantly with HM levels in soil.•L. esculentum was documented by a bioconcentration factor > 1.0 for most HMs.•The translocation of HMs by L. esculentum was below 1 for most examined HMs.