Effect of ethylenediaminetetraacetic acid and biochar on Cu accumulation and subcellular partitioning in Amaranthus retroflexus L.
Phytoremediation combined with amendments and stabilization technologies are two crucial methods to deal with soil contaminated with heavy metals. Copper (Cu) contamination in soil near Cu mines poses a serious threat to ecosystems and human health. This study investigated the effect of ethylenediaminetetraacetic acid (EDTA) and biochar (BC) on the accumulation and subcellular distribution of Cu in Amaranthus retroflexus L. to demonstrate the remediation mechanism of EDTA and BC at the cellular level. The role of calcium (Ca) in response to Cu stress in A. retroflexus was also elucidated. We designed a pot experiment with a randomized block of four Cu levels (0, 100, 200, 400 mg kg−1) and three treatments (control, amendment with EDTA, and amendment with BC). The subcellular components were divided into three parts (cell walls, organelles, and soluble fraction) by differential centrifugation. The results showed that EDTA amendment significantly increased (p < 0.05) the concentrations of Cu in root cell walls and all subcellular components of stems and leaves (cell walls, organelles, and the soluble fraction). EDTA amendment significantly increased (p < 0.05) the proportion of exchangeable fraction and carbonate fraction in the soil. While BC amendment significantly decreased (p < 0.05) the concentrations of Cu in root cell walls and the root soluble fraction, it had no significant effects on Cu concentrations in the subcellular components of stems and leaves. The results revealed that EDTA mainly promoted the transfer of Cu to aboveground parts and accumulation in subcellular components of stems and leaves, while BC mainly limited Cu accumulation in root cell walls and the root soluble fraction. Ca concentrations in cell walls of roots, stems, and leaves increased as the Cu stress increased in all treatment groups, indicating that Ca plays an important role in relieving Cu toxicity in Amaranthus retroflexus L.
KeywordsCu Ca Ethylenediaminetetraacetic acid (EDTA) Biochar Subcellular distribution Amaranthus retroflexus L.
This work was supported by the National Key R&D Program of China (2017YFD0801300); Key R&D Program of Shanxi Province of China (201703D211014); Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering, MOE (KLIEEE-16-03); Shandong Provincial Key Research and Development Program (2016CYJS05A02); and Key Research and Development Program of Shandong (2018GSF117024)
- Aguilar R, Hormazábal C, Gaete H, Neaman A (2011) Spatial distribution of copper, organic matter and pH in agricultural soils affected by mining activities. J Soil Sci Plant Nut 11:125–145Google Scholar
- Cataldo S, Gianguzza A, Pettignano A, Pettignano A, Sammartano S (2012) Complex formation of copper(II) and cadmium(II) with pectin and polygalacturonic acid in aqueous solution. An ISE-H+ and ISE-Me2+ electrochemical study. Int J Electrochem Sci 7:6722–6737Google Scholar
- Huang L, Zhang HQ, Song YY, Yang YR, Chen H, Tang M (2017) Subcellular compartmentalization and chemical forms of lead participate in lead tolerance of Robinia pseudoacacia L. with Funneliformis mosseae. Front Plant Sci 8:517–528Google Scholar
- Jiang XJ, Luo YM, Zhao QG (2001) Study on phytoremediation of cadmium contaminated soil and the EDTA regulation. Soil 33:197–201 (in Chinese)Google Scholar
- Nedjimi B (2018) Heavy metal tolerance in two Algerian saltbushes: a review on plant responses to cadmium and role of calcium in its mitigation. In: Hasanuzzaman M, Fujita M, Oku H, Nahar K, Hawrylak-Nowak B (eds) Plant nutrients and abiotic stress tolerance. Springer, Singapore, pp 205–220CrossRefGoogle Scholar
- Shahid M, Ferrand E, Schreck E, Dumat C (2013) Behavior and impact of zirconium in the soil-plant system: plant update and phytotoxicity. Rev Environ Contam Toxicol 221:107–127Google Scholar
- Wang Y, Shen H, Xu L, Zhu XW, Li C, Zhang W, Xie Y, Gong YQ, Liu LW (2015) Transport, ultrastructural localization, and distribution of chemical forms of lead in radish (Raphanus sativus L.). Front Plant Sci 6:293–305Google Scholar