Uptake of α-HCH by wheat from the gas phase and translocation to soil analyzed by a stable carbon isotope labeling experiment. (February 2021)

• Record Type: Journal Article
• Authors: Liu, Xiao; Bonhomme, Josephine; Merbach, Ines; Kümmel, Steffen; Richnow, Hans Hermann
• Is Part Of: Chemosphere. Volume 264(2021)Part 2
• Publication Date: 2021-02
• Subjects: Hexachlorocyclohexane isomers -- Carbon isotope composition -- Uptake -- Translocation; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128489
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Hexachlorocyclohexane isomers (HCH) are persistent organic pollutants which cause serious environmental pollution. Phytoextraction is one of the strategies of phytoremediation, which was considered as a promising method for the clean-up of HCH contaminated field sites. To understand the uptake and translocation mechanisms of HCH in soil-plant system, the uptake of HCH from the gas phase was investigated in a tracer experiment with 13 C-labeled α-HCH. The results provide new insights on the uptake mechanism of HCH and allow the elucidation of transport pathways of POPs from the leaves to the rhizosphere. A higher dissipation of α-HCH in planted set-ups versus unplanted controls indicated next to intensive biodegradation in the rhizosphere the removal of HCH by root uptake, accumulation and possible transformation within plants. Analyzing the carbon isotopic composition (δ 13 C) of α-HCH in the soil of unplanted controls revealed a change of 15.8–28.6‰ compared to the initial δ 13 C value, indicating that a soil gas phase transportation of α-HCH occurred. Additionally, higher δ 13 C values of α-HCH were observed in bulk and rhizosphere soil in non-labeled treatments compared to unplanted controls, revealing the uptake of α-HCH from the gas phase by the leaves and the further translocation to the roots and finally release to the rhizosphere. This uptake by the leaves and the subsequent translocation of α-HCH within the plant is further indicated by the observed variations of the δ 13 C value of α-HCH in different plant tissues at different growth stages. The uptake and translocation pathways of α-HCH from the gas phase need to be considered in phytoremediation. Graphical abstract: Image 1 Highlights: Carbon isotope composition analysis was applied to identify the plant uptake process. The uptake of α-HCH by plant tissues via gas phase was identified. The release of α-HCH from root to soil was identified by δ 13 C values. Amount of α-HCH by plant tissue uptake was quantified by isotope dilution analysis.