Plants as models for chromium and nickel risk assessment

Abstract

The adverse effects of Cr(III), Cr(VI), and Ni(II) expressed as root and shoot growth inhibition, metal accumulation and translocation throughout plants, and genotoxicity study were examined. To examine phytoxicity and metal accumulation, Vicia sativa, Raphanus sativus, Zea mays and Sinapis alba plants were used. Except for S. alba root growth inhibition, Ni had the strongest inhibitory effect on root and shoot growth. The inhibitory rank order based on IC₅₀ values was Ni(II) > Cr(VI) > Cr(III). Z. mays was the least sensitive to all metals. While the accumulation of Cr was higher in the roots than the upper plant parts, Ni transport to shoots was at least two times higher than that of Cr. The highest accumulation of Cr was found in Z. mays and that of Ni in V. sativa and Z. mays roots. For all plants, the translocation factor was higher for Cr(VI) than for Cr(III). The translocation factor for Ni was several times higher than those of Cr. For mutagenicity assay, root tips of V. sativa, R. sativus and Z. mays were used. All metals exerted a significant increase of chromosomal aberrations and the rank order of aberrations was: Cr(VI) > Ni(II) > Cr(III). Genotoxic effects of metals were also determined by analysis of micronuclei frequency in the pollen tetrads of Tradescantia plants. None of metals significantly stimulated micronuclei frequency and the genotoxic effect decreased in the following order: Cr(VI) ≥ Ni(II) > Cr(III).

Quantification of Heavy Metals in Mining Affected Soil and Their Bioaccumulation in Native Plant Species

“…Essential (Mn, Mg, Zn Fe, Ni, and Cu) and non-essential (Cd, Cr, and Pb) metals are accumulated by different plant species from soil. Bioaccumulation of heavy metals in plants is also controlled by environmental conditions such as soil pH, organic matter and heavy metal concentrations (Fargašová 2012;Liu et al 2012). Soil phosphorous concentrations can also affect the metal uptake and their bioaccumulation in plant tissues.…”

Phytoremediation potential of Phalaris arundinacea, Salix viminalis and Zea mays for nickel-contaminated soils

“…It means that plants transferred only 2-8% Ni from the roots to the aboveground parts. Also, in the studies of Fargasova (2012) and Antonkiewicz et al (2016), the values of TFs for Z. mays were lower than for other species investigated plants. According to Seregin et al (2003), Z. mays belongs to excluder plants, as its roots constitute a barrier limiting Ni transport to the shoots.…”

Dose dependent rhizospheric Ni toxicity evaluation: Membrane stability and antioxidant potential of Vigna species

“…Thus, the stronger cell wall itself acts as a physical barrier against toxic metal ions (Fargasova, 2012). The substrate affinity of POD is higher than that of CAT (Mhamdi et al, 2010).…”

“…Oxidative damage could result when the balance between the detoxification of the ROS products and the antioxidative system is altered (Yusuf et al, 2011). The antioxidative activity may be of fundamental significance for the plants in their response against heavy metal stress including Ni (Fargasova, 2012). However, excess Ni has been found to reduce the activity of many cellular antioxidant enzymes and plant's capability to scavenge ROS, leading to ROS accumulation and finally oxidative stress in plants (Gill and Tuteja, 2010).…”