Effect of cadmium, zinc and substrate heterogeneity on yield, shoot metal concentration and metal uptake by Brassica juncea: implications for human health risk assessment and phytoremediation

Abstract

313 ResearchBlackwell Publishing, Ltd.Effect of cadmium, zinc and substrate heterogeneity on yield, shoot metal concentration and metal uptake by Summary• Heavy metal contaminants are usually heterogeneously distributed in soils. However, their effects on plants are usually studied under homogeneous conditions. Here we examined the effects of Cd, Zn, and their spatial distribution on shoot yield, shoot metal concentrations, and total metal uptake by Brassica juncea .• One Cd concentration and three Zn concentrations were used. Metals were applied to the substrate either singly or in combination.• Heterogeneous metal distribution enabled growth reduction to be avoided, even at concentrations that were highly phytotoxic when distribution was homogeneous. Moderate Zn contamination reduced Cd uptake by 40%. With high Zn contamination, metal concentrations were two to four times lower when metals were heterogeneously, rather than homogeneously, distributed; shoot yields were up to 24-times greater and total shoot Cd and Zn uptakes were on average six-times higher.• It is suggested that human health risk from consuming plant parts grown on Cd-contaminated substrates is lower when Zn is also present and metal distribution is heterogeneous, and that phytoremediation potential is greater when contaminant distribution is heterogeneous.

Amaranthus Tricolor Has the Potential for Phytoremediation of Cadmium‐Contaminated Soils

“…It has been reported that B. juncea does not have high Cd accumulating ability when grown in Cd-contaminated soils (Podar, Ramsey, and Hutchings 2004). Our study also showed low Cd accumulation in shoots of B. juncea as well as P. sachalinense under soil culture conditions (Fig.…”

Resposta da couve-da-Malásia (Brassica chinensis L. var. parachinensis (Bailey) Sinskaja) à deficiência nutricional

“…Em condições tropicais a deficiência de zinco é muito freqüente e, no Brasil, também tem limitado a produtividade de algumas culturas (PRADO et al, 2008;TEIXEIRA et al, 2008). A presença de Zn no substrato de cultivo também reduz a absorção de cádmio em Brassica juncea, metal pesado carcinogênico (PODAR et al, 2004). …”

“…Dentre os macronutrientes, N e P são os que mais interferem na produtividade dessas plantas, mas elas também são exigentes em Ca e S, sendo o K e o N retirados do solo em maiores quantidades (FURLANI et al, 1978;SHARMA, 2008). Em função dessa capacidade extratora as brássicas estão sendo testadas com sucesso para detectar metais pesados em substratos diversos, sendo candidatas à fitorremediação (HAN et al, 2004;PODAR et al, 2004;LINDBLOM et al, 2006;LI-XIAN et al, 2007;QI-TANG et al, 2007). Brassica napus L. acumula grandes quantidades de Fe, Mn, Zn, As, Cr, Ni, Cu, Pb, Co, Mo, Cd, Ag e Tl na raiz, mas a transferência desses metais para a parte aérea das plantas é limitada e para as sementes mais ainda, o que garante sua qualidade como fonte de alimento humano (MESTEK et al, 2007).…”

The Effects of More Realistic Forms of Lead Heterogeneity in Soil on Uptake, Biomass and Root Response of Two Brassica species

“…Earlier Studies [53,[12][13][14] reported that the effect of heterogeneity of Cd and Zn in soil on plant biomass and uptake. Findings from this study suggest that predictions of plant uptake and plant performance for use in phytoremediation and risk assessment from homogeneous pot trials may not be accurate representations of plant uptake and performance under field conditions, which are usually heterogeneous to some extent.…”